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Locked
Aliexpress Chinese ES9039Q2M module... what can we do with it?
- By jean-paul
- Digital Line Level
- 10 Replies
Marantz PM-66SE KI Signature PSU Modifications
- By Hamish119
- Solid State
- 23 Replies
I recently purchased a Marantz PM-66SE KI Signature (the same circuit as the PM-40SE, PM-44SE and PM-66SE, but with a toroidal transformer, a sprinkling of 'boutique' capacitors and a copper-plated chassis.
N.B. The PM-66* variants have an extra transformer winding for the remote control features.
Whilst it appeared to be fully-functional (** I normally listen with the 'Source DIRECT' button engaged **), I was concerned by the amount of heat dissipated by Q801 & Q802.
I resolved to reduce the amount of heat dissipated by these transistors with the minimum amount of circuit modifications and parts.
I noted that R802 had been replaced. I also noted that Q801 was loose! Too much heat in a TO220 package.
Marantz_PM-66SE_KI_1_small.mp4
Marantz_PM-66SE_KI_2.mp4
N.B. I had a Marantz PM-44SE that used to intermittently drop-out the speaker relay, then re-engage a few seconds later. That amplifier 'disappeared' before I could investigate the cause (I now suspect Q801 as aove).
After measuring the voltage drops across R802 (47R / ~5V drop) and R804 (47R / ~3V drop), I determined that the +24V rail was supplying ~100mA (worst case - speaker + source direct relays engaged) and the -18V rails was supplying ~66mA (worst case - ALL LEDs illuminated).
It's not surprising that (according to 'the Internet') R802 is the most common failure with these amplifiers - it's severely underrated. It's a design oversight!.
R804, D804 & D805 also take a beating in the default configuration.
Marantz_PM-66SE_KI_PSU.jpg
Marantz_PM-66SE_KI_Resistor.jpg
** When I disengaged the 'Source Direct' relay, I lost the right channel (intermittently). Re-engaging the 'Source Direct' relay restored the right channel (always).
After replacing ALL the semiconductors and capacitors, the amplifier was completely destroyed. 😱
The above sentence is completely untrue and is precisely what happens when you believe 'misinformation' on the Internet. 🙄
The right channel could be restored (temporarily) by moving the large ribbon cable (WV01), but would disappear minutes/hours later.
After chasing the intermittent problem, I discovered that the (never used) 'Balance' control had been 'whacked' by a previous (l)User.
Resoldering ALL the pins restored normal operation (but for how long?).
Balance_Control_Knob.jpg
N.B. The PM-66* variants have an extra transformer winding for the remote control features.
Whilst it appeared to be fully-functional (** I normally listen with the 'Source DIRECT' button engaged **), I was concerned by the amount of heat dissipated by Q801 & Q802.
I resolved to reduce the amount of heat dissipated by these transistors with the minimum amount of circuit modifications and parts.
I noted that R802 had been replaced. I also noted that Q801 was loose! Too much heat in a TO220 package.
Marantz_PM-66SE_KI_1_small.mp4
Marantz_PM-66SE_KI_2.mp4
N.B. I had a Marantz PM-44SE that used to intermittently drop-out the speaker relay, then re-engage a few seconds later. That amplifier 'disappeared' before I could investigate the cause (I now suspect Q801 as aove).
After measuring the voltage drops across R802 (47R / ~5V drop) and R804 (47R / ~3V drop), I determined that the +24V rail was supplying ~100mA (worst case - speaker + source direct relays engaged) and the -18V rails was supplying ~66mA (worst case - ALL LEDs illuminated).
It's not surprising that (according to 'the Internet') R802 is the most common failure with these amplifiers - it's severely underrated. It's a design oversight!.
R804, D804 & D805 also take a beating in the default configuration.
Marantz_PM-66SE_KI_PSU.jpg
Marantz_PM-66SE_KI_Resistor.jpg
** When I disengaged the 'Source Direct' relay, I lost the right channel (intermittently). Re-engaging the 'Source Direct' relay restored the right channel (always).
After replacing ALL the semiconductors and capacitors, the amplifier was completely destroyed. 😱
The above sentence is completely untrue and is precisely what happens when you believe 'misinformation' on the Internet. 🙄
The right channel could be restored (temporarily) by moving the large ribbon cable (WV01), but would disappear minutes/hours later.
After chasing the intermittent problem, I discovered that the (never used) 'Balance' control had been 'whacked' by a previous (l)User.
Resoldering ALL the pins restored normal operation (but for how long?).
Balance_Control_Knob.jpg
Attachments
For Sale Lots of PCBs - VRDN H9KPXG Milpitas UDP3 AmyAlice Holy Grail R21
PCB's and some full kits "recently" purchased (early Oct 2024) received from JLCPCB as an ode to @Mark Johnson , @lhquam , @tombo56 , & @Zen Mod for all they have given to the community.
UPDATE April 28: (See the table for price/availability. Shipping is about $6 in USA. International shipping tends to be a lot more.)
Send me a PM and I can provide more details. All this stuff is what I wanted to build and just got in bulk with the hopes of helping others out as well with a "reverse group buy" approach.
Yes It Can Drive An F4 Full Kits - (just PCB's shown of course in picture
Mark Johnson's BJT Simple Matcher
Holy Grail by @lhquam
FETS (Not matched) for Holy Grail (FQA28N15/IXTQ36P15) for Holy Grail
VRDN - Voltage Regulator De-Noiser by @Mark Johnson
AC Power Relay Soft Start - H9KPXG by @Mark Johnson
Milpitas for M2x Amp by @Mark Johnson
Pearl 3 PSU Board(s) "UDP3" by @Mark Johnson
AmyAlice by @Mark Johnson
Korg B1 Soft Heat by @Zen Mod
Tombo's R25 PCBs (replacement for R21 boards with PSU)
Mark Johnson's Cheapomodo Full Kit
UPDATE April 28: (See the table for price/availability. Shipping is about $6 in USA. International shipping tends to be a lot more.)
- IPS Boards for M2x - Milpitas IPS9 available currently (eventually there will be IPS6 and IPS7 kits available and IPS8 Cederburg PCBs). Making kits up takes a lot of effort, so it'll be a few weeks before these are posted.
- Yes It Can Drive An F4 (YICDAF4) full kits available. 15 qty stereo kits available with (or without) tightly matched B546C BJTs. Parts kits without the PCBs are also available if that's all that's needed.
- BJT Simple Matcher Full kits available. (around 10 left)
- AmyAlice Full kits available (still have lots). Really nice 2oz outer copper, 2mm board thickness, and ENIG finish!
- Korg B1 Soft Heat Kits available.
- H9KPXG Full kits available. Made up about 10 kits. (2oz outer copper, purple PCB)
- VRDN Full kits are almost done. Need a couple more weeks to get them completed and figure out cost. (2oz outer copper, blue PCB)
- Cheapomodo R3 Full kits available (20 kits available now).
- R25 PCBs by tombo56 available for those wanting to try out the active rectifier approach to a PSU (Limited quantity on hand). These are the updated version of the R21 boards now as a single PSU package. Really nice 2oz outer copper, 2mm board thickness, and HASL finish!
- Holy Grail PCBs and unmatched FETs (FQA28N15P/ITXQ36P20P) available (matching not necessary according to Lynn). Also have some FQA36P20 if you'd prefer those over the ITXQ36P20 although they seem to be the exact same part overall. Some matched N to N and P to P by Vgs (measured at 50°C, 1A, 24V) are available if needed.
- A few FQA40N25/FQA36P20 are available as well, so that's what you need for XRK and AKSA's Alpha Nirvana 39.
- Some matched by Vgs of IRFP140/9140 parts are available if anyone wants those. They are IR brand and are N channel matched and P channel matched, not N to P though for awareness. Quads and a few octets available as well matched N to N and P to P by Vgs (measured at 50°C, 1A, 24V).
- Replacements for the Toshiba 2SK2013/2SJ313 are FQA3N30/FQP3P20 are also available matched for either NN and PP, or NNPP (matched at 20mA, 40°C, 24V)
- Now that the KSC/2SC3503E & KSA/2SA1381E are near unobtainable, the KEC versions KTC3503-Y and KTA1381-Y are available for super good price. Not matched yet, however, that could likely be done if needed. Need to still figure out how to do this, so it'll be a while to get it all done by Vbe and Hfe.
- A few remaining ACA Mini "Modification" kits suggested by @ClaudeG are available as well. Reference this link.
- HPA-1 boards with the hard to find components are available for a few interested folks.
- Willing to 3D print items for super low cost (a buck or two). Search "3D" under the "Parts" to see what has already been posted. Some examples are the vertical Antek transformer mount and Zenductor II "chassis" feet. The designs are shared freely if you have access to a 3D printer. We can make up a custom design for your needs as well if that's helpful.
- Lastly, I have a Vinyl cutter if anyone wants custom stickers made up to put on an amp, or preamp. I'm willing to make a small quantity for custom designs (not bulk orders as it's really time consuming to "weed" the vinyl). Send me a PM if that's something I can help with.
Send me a PM and I can provide more details. All this stuff is what I wanted to build and just got in bulk with the hopes of helping others out as well with a "reverse group buy" approach.
Yes It Can Drive An F4 Full Kits - (just PCB's shown of course in picture
Mark Johnson's BJT Simple Matcher
Holy Grail by @lhquam
FETS (Not matched) for Holy Grail (FQA28N15/IXTQ36P15) for Holy Grail
VRDN - Voltage Regulator De-Noiser by @Mark Johnson
AC Power Relay Soft Start - H9KPXG by @Mark Johnson
Milpitas for M2x Amp by @Mark Johnson
Pearl 3 PSU Board(s) "UDP3" by @Mark Johnson
AmyAlice by @Mark Johnson
Korg B1 Soft Heat by @Zen Mod
Tombo's R25 PCBs (replacement for R21 boards with PSU)
Mark Johnson's Cheapomodo Full Kit
Comparison of various motor structures
- Subwoofers
- 3 Replies
Hi,
Below is a comparison of various motor structures for subwoofers.
JBL's differential drive wins. Its both coils are overhung and yet produces less distortion, please see Figure 8A on page 7 in attached technote. a) Can anyone tell why?
My guess is that since both the coils are wound opposite to each other on the same pole piece its inductance is nullified (maybe very little remains) as compared to other technologies. In a typical subwoofer the inductance is fairly high due to 4 layer windings and it varies as the voice coil moves in and out, when coil is in the inductance is more and when coil is out the inductance is less. This produces audible distortion. Since differential drive has very less inductance it can firstly go higher in frequency and produce less excursion related distortion. b) Am I making the right conclusion?
Also, the whitepaper states symmetrical field geometry, I dont understand how it helps as ultimately both coils are overhung and will have same non linearity of typical overhung designs. c) Can anyone please explain how symmetric field geometry works to reduce distortion?
If b) is true then it means we could just use multiple small subwoofers instead of 1 big one as the inductance of smaller drivers is less, even if it changes with excursion, the resulting distortion will be higher up in frequency than subwoofer use, hence harmless. d) Do you agree? Of course, XMAX of smaller drivers is less than a bigger one, agreed. For this discussion, let us keep it aside.
Please provide your thoughts for a), b),c) and d).
Attached is technical note of differential drive.
Thanks and Regards,
WonderfulAudio
Below is a comparison of various motor structures for subwoofers.
JBL's differential drive wins. Its both coils are overhung and yet produces less distortion, please see Figure 8A on page 7 in attached technote. a) Can anyone tell why?
My guess is that since both the coils are wound opposite to each other on the same pole piece its inductance is nullified (maybe very little remains) as compared to other technologies. In a typical subwoofer the inductance is fairly high due to 4 layer windings and it varies as the voice coil moves in and out, when coil is in the inductance is more and when coil is out the inductance is less. This produces audible distortion. Since differential drive has very less inductance it can firstly go higher in frequency and produce less excursion related distortion. b) Am I making the right conclusion?
Also, the whitepaper states symmetrical field geometry, I dont understand how it helps as ultimately both coils are overhung and will have same non linearity of typical overhung designs. c) Can anyone please explain how symmetric field geometry works to reduce distortion?
If b) is true then it means we could just use multiple small subwoofers instead of 1 big one as the inductance of smaller drivers is less, even if it changes with excursion, the resulting distortion will be higher up in frequency than subwoofer use, hence harmless. d) Do you agree? Of course, XMAX of smaller drivers is less than a bigger one, agreed. For this discussion, let us keep it aside.
Please provide your thoughts for a), b),c) and d).
Attached is technical note of differential drive.
Thanks and Regards,
WonderfulAudio
ZEN Amplifier Mini with IRF610 as Headphone Amplifier for 32 Ohm
The ZEN Amplifier concept is simple. But it works great.
Here is such an amplifier but with less current and uses IRF610 as MOSFET.
It makes a simple and sweet headphone amp.
Building shouldn't be difficult.
The heatsinking it takes is not so much.
There is some THD, but it is mainly 2nd harmonic.
So, it would be good listening.
The amp is designed for 32 Ohms headphones.
For other impedances it may need tweaking to make it alright.
Here is such an amplifier but with less current and uses IRF610 as MOSFET.
It makes a simple and sweet headphone amp.
Building shouldn't be difficult.
The heatsinking it takes is not so much.
There is some THD, but it is mainly 2nd harmonic.
So, it would be good listening.
The amp is designed for 32 Ohms headphones.
For other impedances it may need tweaking to make it alright.
USB UAC2+HID Multichannel input/output interface York
- By eclipsevl
- Vendor's Bazaar
- 222 Replies
Hello DiyAudio community,
TL;DR: This is a USB transport for audio output (up to 8ch) and input (2ch for now) and user device control (e.g., DSP management) from PC (MacOS/Linux/Windows) thru I2C/GPIO. Including bootloader for remote firmware update, flexible device configuration, HID interface, multiple audio output options, integration with SigmaStudio (simultanious audio playback and ADAU DSP configuration). Compact module available in USB-C and USB-B versions, isolated or non-isolated.
Latest docs, config tool, link to buy:
http://york.eclipsevl.org/
So, the story started when I needed a USB transport for audio output and another channel for device control, such as for managing DSP.
Last time, I solved this problem using a USB hub and a USB to Serial converter. This way, I assembled the required interface from 4 chips:
https://www.diyaudio.com/community/threads/audio-transport-module-york.406025/
(first post)
I tried to combine everything into one XMOS chip. This was also a working solution, but there was a big problem with the availability of the chips, especially in the desired package.
Thus, developing the transport on the pic32mz seemed the most logical to me. The first prototype module was based on Dortonyan’s project from Vegalab: in terms of circuitry, it almost completely repeated the original project and was designed for two-channel audio output, plus a serial interface. During testing of the firmware based on the original source code, several problems were identified when working in different OSs. The serial port was also not fully implemented.
I posted my version of the firmware with fixes in the original thread and on GitHub: https://github.com/eclipsevl/york_pic32mz_uac2_osfw/
After that, I continued working on the functions I needed. The following features were implemented:
1. Bootloader. Necessary for firmware updates via USB, without a programmer.
2. Flexible device configuration using a PC utility (which is also used for firmware updates).
3. HID interface for transmitting service information and device configuration. Initially, I planned to use the serial port, but HID is much more suitable.
4. Serial interface, which can be optionally enabled.
5. Various additional audio output options: s/pdif, 8-channel TDM, dual i2s (for using some DACs channel-by-channel in mono mode). Recently I also added support for old dacs with clock/data/latch interface. I.e. direct connection to dac ICs such as AD1862/PCM1702 etc is also possible without glue logic.
6. Various clocking options: module oscillators, external clock (slave mode), internal PLL clocking.
7. I2C port and library for integration with SigmaStudio: for simultaneous audio input/output and DSP ADAU programming.
This last feature is currently a unique combination and fits well into DSP projects: https://www.diyaudio.com/community/threads/freedsp-octavia.393804/page-18#post-7625685
The configuration and firmware update utility looks like this:
Device name and PID/VID settings
Audio interface settings:
Input of up to 2 PCM channels, up to 192kHz (384kHz with external clocking at 1024fs)
Output of 2 PCM channels, up to 192kHz
(384kHz with external clocking)
Output of 8 channels in TDM8 mode (up to 96kHz, clocked by PLL)
Output of 8 channels in 2xI2S mode
Output of 2 S/PDIF channels, up to 192kHz clocked by PLL
And of course, in the simplest version, this module can work similarly to any USB interface, in slave or master mode.
DSD has not been tested yet.
Photo of the module, second version.
The additional 4-pin connector can be configured as i2c/uart/gpio, and is also used for forced entry into the bootloader (in case of unsuccessful software update).
Available in two versions: USB-C and USB-B. The transport itself is quite compact: it fits into an area of about 2x2 cm - which is important for integration into other devices.
So I'm working on a smaller PCB with same functionality.
Later I'm going to release a software library to basically enable anyone to create their own app for PC to control custom devices: toggle GPIO of USB module/send I2C transactions.
The module is available with USB-B or USB-C, the price is 49 Euro.
For purchase PM me. Also available on Tindie:
Multichannel USB UAC2+HID+CDC interface York
I'm open for requests for additional features but whether it is going to be added to the firmware depends on hardware limitations and time required to implement it.
Latest version of config tool:
https://york.eclipsevl.org/york_config_tool.zip
P.S. Huge thanks to:
1. Alexey (Dortonyan) for publishing the project. His work laid the foundation, and without it, this project would never happen.
2. Beta testers of the first version: @CyberPit, @Ludilu
UPD Oct 28th 2024:
Documentation draft attached
UPD Feb 17th 2025:
Latest docs, config tool, link to buy:
http://york.eclipsevl.org/
TL;DR: This is a USB transport for audio output (up to 8ch) and input (2ch for now) and user device control (e.g., DSP management) from PC (MacOS/Linux/Windows) thru I2C/GPIO. Including bootloader for remote firmware update, flexible device configuration, HID interface, multiple audio output options, integration with SigmaStudio (simultanious audio playback and ADAU DSP configuration). Compact module available in USB-C and USB-B versions, isolated or non-isolated.
Latest docs, config tool, link to buy:
http://york.eclipsevl.org/
So, the story started when I needed a USB transport for audio output and another channel for device control, such as for managing DSP.
Last time, I solved this problem using a USB hub and a USB to Serial converter. This way, I assembled the required interface from 4 chips:
https://www.diyaudio.com/community/threads/audio-transport-module-york.406025/
(first post)
I tried to combine everything into one XMOS chip. This was also a working solution, but there was a big problem with the availability of the chips, especially in the desired package.
Thus, developing the transport on the pic32mz seemed the most logical to me. The first prototype module was based on Dortonyan’s project from Vegalab: in terms of circuitry, it almost completely repeated the original project and was designed for two-channel audio output, plus a serial interface. During testing of the firmware based on the original source code, several problems were identified when working in different OSs. The serial port was also not fully implemented.
I posted my version of the firmware with fixes in the original thread and on GitHub: https://github.com/eclipsevl/york_pic32mz_uac2_osfw/
After that, I continued working on the functions I needed. The following features were implemented:
1. Bootloader. Necessary for firmware updates via USB, without a programmer.
2. Flexible device configuration using a PC utility (which is also used for firmware updates).
3. HID interface for transmitting service information and device configuration. Initially, I planned to use the serial port, but HID is much more suitable.
4. Serial interface, which can be optionally enabled.
5. Various additional audio output options: s/pdif, 8-channel TDM, dual i2s (for using some DACs channel-by-channel in mono mode). Recently I also added support for old dacs with clock/data/latch interface. I.e. direct connection to dac ICs such as AD1862/PCM1702 etc is also possible without glue logic.
6. Various clocking options: module oscillators, external clock (slave mode), internal PLL clocking.
7. I2C port and library for integration with SigmaStudio: for simultaneous audio input/output and DSP ADAU programming.
This last feature is currently a unique combination and fits well into DSP projects: https://www.diyaudio.com/community/threads/freedsp-octavia.393804/page-18#post-7625685
The configuration and firmware update utility looks like this:
Device name and PID/VID settings
Audio interface settings:
Input of up to 2 PCM channels, up to 192kHz (384kHz with external clocking at 1024fs)
Output of 2 PCM channels, up to 192kHz
(384kHz with external clocking)
Output of 8 channels in TDM8 mode (up to 96kHz, clocked by PLL)
Output of 8 channels in 2xI2S mode
Output of 2 S/PDIF channels, up to 192kHz clocked by PLL
And of course, in the simplest version, this module can work similarly to any USB interface, in slave or master mode.
DSD has not been tested yet.
Photo of the module, second version.
The additional 4-pin connector can be configured as i2c/uart/gpio, and is also used for forced entry into the bootloader (in case of unsuccessful software update).
Available in two versions: USB-C and USB-B. The transport itself is quite compact: it fits into an area of about 2x2 cm - which is important for integration into other devices.
So I'm working on a smaller PCB with same functionality.
Later I'm going to release a software library to basically enable anyone to create their own app for PC to control custom devices: toggle GPIO of USB module/send I2C transactions.
The module is available with USB-B or USB-C, the price is 49 Euro.
For purchase PM me. Also available on Tindie:
Multichannel USB UAC2+HID+CDC interface York
I'm open for requests for additional features but whether it is going to be added to the firmware depends on hardware limitations and time required to implement it.
Latest version of config tool:
https://york.eclipsevl.org/york_config_tool.zip
P.S. Huge thanks to:
1. Alexey (Dortonyan) for publishing the project. His work laid the foundation, and without it, this project would never happen.
2. Beta testers of the first version: @CyberPit, @Ludilu
UPD Oct 28th 2024:
Documentation draft attached
UPD Feb 17th 2025:
Latest docs, config tool, link to buy:
http://york.eclipsevl.org/
Bass guitar & amp build
- By soundbrigade
- Instruments and Amps
- 25 Replies
Many years ago I bought a BYOB (Build Your Own Buitar) from Hobby Lobby and got it together a few years ago. As a non-musician I have since decided that maybe I could eventually learn to play a frew notes on a bass guitar so I bought a Harley David ... Bentley P-bass kit from the German shop Thomann.
Whilst making work on the body (I will borrow a jig saw for the headstock - my design), I have started looking for a amp/speaker combo. Luckily, with workers replacing the old roofs, and throwing away plywood offcuts, I have enough material for a box to hold that one. It's not furniture grade, but still 15mm pretty acceptable plywood (often referred to as "plyfa" in Swedish). (All dimension in normal units (centigrade).
The guitar is the Harley Benton P-bass as it looks nicer and I just found a heavy coaxial speaker from Master Audio (Italy), an CSX08, an 8", 4.5kg piece with what looks like a small horn tweeter. Stated freqency range 63Hz - 20kHz (could be lower) and recommended crossover frequency of 1.7kHz. 6dB/12dB crossover.
I had an idea to go for a speaker box of approx 400 x 500 x 250mm (16" x 20" x 10") or slightly smaller, using a sort of Onken design or maybe just a single slit, but nothing decided yet.
When it comes to an amp, there's an "issue". I am not going to play at Stockwood ... errr ... Woodstock, but at home and, if I learn more that one note at local events in our old folks club and I think 50W amperage will be enuff.
I've gotten a pair of simple 50W transistor amps built from cheap Chian kits and I guess one of these would be perfect. Else a similar kit from EliExpress is considered: THIS ONE.
For testing I have gotten a D-class chipamp, which had been nice as it doesn't requires a lot of space heatsinks and whatnot. A simple SMPS will do fine (it it works).
I love to fiddle with things and make things a bit diffrunt. I've got 50 shades of pink .. 2 actually for the bass and I will try to mix them in some "odd way". Also gotten a green pickguard that will match the pink body perfectly
.
The speaker/amp combo will be covered in vinyl (black-ish) and apart from thinking of power amplifier, I must look up a decent preamp.
This is my plan and I am open for suggestions ... open for REASONABLE suggestions
, remember that this is a mid- to lowfi project. For fun. Low cost.
Whilst making work on the body (I will borrow a jig saw for the headstock - my design), I have started looking for a amp/speaker combo. Luckily, with workers replacing the old roofs, and throwing away plywood offcuts, I have enough material for a box to hold that one. It's not furniture grade, but still 15mm pretty acceptable plywood (often referred to as "plyfa" in Swedish). (All dimension in normal units (centigrade).
The guitar is the Harley Benton P-bass as it looks nicer and I just found a heavy coaxial speaker from Master Audio (Italy), an CSX08, an 8", 4.5kg piece with what looks like a small horn tweeter. Stated freqency range 63Hz - 20kHz (could be lower) and recommended crossover frequency of 1.7kHz. 6dB/12dB crossover.
I had an idea to go for a speaker box of approx 400 x 500 x 250mm (16" x 20" x 10") or slightly smaller, using a sort of Onken design or maybe just a single slit, but nothing decided yet.
When it comes to an amp, there's an "issue". I am not going to play at Stockwood ... errr ... Woodstock, but at home and, if I learn more that one note at local events in our old folks club and I think 50W amperage will be enuff.
I've gotten a pair of simple 50W transistor amps built from cheap Chian kits and I guess one of these would be perfect. Else a similar kit from EliExpress is considered: THIS ONE.
For testing I have gotten a D-class chipamp, which had been nice as it doesn't requires a lot of space heatsinks and whatnot. A simple SMPS will do fine (it it works).
I love to fiddle with things and make things a bit diffrunt. I've got 50 shades of pink .. 2 actually for the bass and I will try to mix them in some "odd way". Also gotten a green pickguard that will match the pink body perfectly
.The speaker/amp combo will be covered in vinyl (black-ish) and apart from thinking of power amplifier, I must look up a decent preamp.
This is my plan and I am open for suggestions ... open for REASONABLE suggestions
, remember that this is a mid- to lowfi project. For fun. Low cost.
Low-profile turntable vibration isolators
- By Mark'51
- Analogue Source
- 1 Replies
I have a feedback problem between my old turntable and speakers. I'm not crazy about using multi-pound weights, a box full of sand or an ugly-as-sin inner tube to address the problem so I started experimenting with a different approach. It started with some floor protectors that are designed for things that have casters on their feet -- they have a cylindrical depression in them, so a small ball bearing can easily roll back & forth inside them For my first experiment I actually got some 1/2" silicone balls, on the theory that they could also damp a certain amount of vibration in the vertical plane. The protectors were placed, plastic spheres dropped in, a plywood piece on top, and finally the TT went down.
It worked pretty darned good! I thought things could be further improved because the cylindrical "bowl" permits the spheres to freely move along the axis of the cylinder so the TT had a tendency to drift around. What I really needed was some "pucks" with a spherical bowl shape so they would work on both the X and Y axes. I looked around but didn't find anything the right size, or didn't cost too much -- so I decided to make some.
Here's my first shot at a home-made version:
I have a small machine shop so it actually wasn't too difficult to make this guy. I first tried printing one on my 3D printer but the vertical steps interfered with the free motion of the sphere. It probably would work with something better than an Ender 3. An SLA printer might be the ticket, but I don't have one.
Interestingly, the oscillation frequency of the sphere is independent of the TT mass, it only depends on the bowl's radius of curvature. And it doesn't take a very large radius of curvature to achieve a very low effective cutoff frequency. I calculate that a bowl with a 4.4cm radius of curvature has an oscillation frequency of just TWO HERTZ!
The one in the photo has a natural oscillation frequency around 3 Hz so I believe the math. I'm grinning a lot over this one.
The fact that the frequency doesn't depend on the TT mass resting on them means that the entire system, consisting of 4 of these pucks, has the SAME cutoff frequency as just one of them. I love physics....when it works in my favor 😆
I had thought that the oscillation frequency would be the same as for a pendulum, but it isn't. The fact that the sphere rotates (due to friction) changes its natural oscillation frequency so the oscillation period is slightly longer, compared to a simple pendulum. The approximate period is given by: T = 2*pi*sqrt((7R)/(5g)), where R is the bowl's radius of curvature and g is the gravitational constant. SI units -- R is in meters, g is 9.81 m/s^2. T is seconds, of course -- 1/sqrt(s^2) = s. I found the formula over on physics.stackexchange.com. It's valid for small-amplitude oscillations, which should be the case here. A simple pendulum's period is given by T = 2*pi*sqrt(R/g) so T isn't THAT different, just a bit longer. Longer is better.....
The shallow bowl means that it wouldn't be too difficult to push the TT off of them, so my final puck design will include a 3D-printed skirt around the outside of each puck so the sphere will fetch up against it and stop.
I bought the spheres from McMaster-Carrr so I could get them quickly, but that ended up costing me $35 for 10 of them. Rubber spheres can be had on ebay or Amazon for less, if you're willing to wait. Grainger might be another source. I got the acetal plastic from Tap Plastics, $5 for 4 of them, 1/2" thick. There also are online metal and plastic suppliers that will cut material to size, although they usually charge a small fee for special cuts. If you go that route, shop around first -- fees can vary quite a bit.
I realize that few of you will own, or have access to, the machine tools I used to make these, but there are other ways to make something similar. For instance, it wouldn't be too difficult to make a mold using a large ball, to cast them out of epoxy resin. The inside surface of a large ~2" ABS plumbing fitting -- an end cap -- has a decent radius. But Its exterior also has a radius, so I don't know how that will work -- if left free to rock, it might behave like a flat piece & that's not what you want. But it MIGHT make be good for creating the bowl, maybe pressing it into epoxy putty. Put mold release on it first.....
It worked pretty darned good! I thought things could be further improved because the cylindrical "bowl" permits the spheres to freely move along the axis of the cylinder so the TT had a tendency to drift around. What I really needed was some "pucks" with a spherical bowl shape so they would work on both the X and Y axes. I looked around but didn't find anything the right size, or didn't cost too much -- so I decided to make some.
Here's my first shot at a home-made version:
I have a small machine shop so it actually wasn't too difficult to make this guy. I first tried printing one on my 3D printer but the vertical steps interfered with the free motion of the sphere. It probably would work with something better than an Ender 3. An SLA printer might be the ticket, but I don't have one.
Interestingly, the oscillation frequency of the sphere is independent of the TT mass, it only depends on the bowl's radius of curvature. And it doesn't take a very large radius of curvature to achieve a very low effective cutoff frequency. I calculate that a bowl with a 4.4cm radius of curvature has an oscillation frequency of just TWO HERTZ!
The one in the photo has a natural oscillation frequency around 3 Hz so I believe the math. I'm grinning a lot over this one.
The fact that the frequency doesn't depend on the TT mass resting on them means that the entire system, consisting of 4 of these pucks, has the SAME cutoff frequency as just one of them. I love physics....when it works in my favor 😆
I had thought that the oscillation frequency would be the same as for a pendulum, but it isn't. The fact that the sphere rotates (due to friction) changes its natural oscillation frequency so the oscillation period is slightly longer, compared to a simple pendulum. The approximate period is given by: T = 2*pi*sqrt((7R)/(5g)), where R is the bowl's radius of curvature and g is the gravitational constant. SI units -- R is in meters, g is 9.81 m/s^2. T is seconds, of course -- 1/sqrt(s^2) = s. I found the formula over on physics.stackexchange.com. It's valid for small-amplitude oscillations, which should be the case here. A simple pendulum's period is given by T = 2*pi*sqrt(R/g) so T isn't THAT different, just a bit longer. Longer is better.....
The shallow bowl means that it wouldn't be too difficult to push the TT off of them, so my final puck design will include a 3D-printed skirt around the outside of each puck so the sphere will fetch up against it and stop.
I bought the spheres from McMaster-Carrr so I could get them quickly, but that ended up costing me $35 for 10 of them. Rubber spheres can be had on ebay or Amazon for less, if you're willing to wait. Grainger might be another source. I got the acetal plastic from Tap Plastics, $5 for 4 of them, 1/2" thick. There also are online metal and plastic suppliers that will cut material to size, although they usually charge a small fee for special cuts. If you go that route, shop around first -- fees can vary quite a bit.
I realize that few of you will own, or have access to, the machine tools I used to make these, but there are other ways to make something similar. For instance, it wouldn't be too difficult to make a mold using a large ball, to cast them out of epoxy resin. The inside surface of a large ~2" ABS plumbing fitting -- an end cap -- has a decent radius. But Its exterior also has a radius, so I don't know how that will work -- if left free to rock, it might behave like a flat piece & that's not what you want. But it MIGHT make be good for creating the bowl, maybe pressing it into epoxy putty. Put mold release on it first.....
How to make a loudspeaker sandwich cone
- By Freedom666
- Full Range
- 169 Replies
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For Sale Acro Acrosound TO-330 Output Transformer
Sold, Thanks for interest!
Acro T0-330 Output Transformer.
Primary: 3800 ohms, screen taps for Ultra Linear operation, Parallel PP 6550s, EL34s
Secondary: 4, 8, 16 ohms
I verified turns ratio & Z ratio using 10V rms 1Khz on the secondary and reading the primary voltage.
$200 plus shipping. US lower 48 only
Acro T0-330 Output Transformer.
Primary: 3800 ohms, screen taps for Ultra Linear operation, Parallel PP 6550s, EL34s
Secondary: 4, 8, 16 ohms
I verified turns ratio & Z ratio using 10V rms 1Khz on the secondary and reading the primary voltage.
$200 plus shipping. US lower 48 only
For Sale Clearance of spot inventory, transistors, vFET, TOKIN THF-51N THF51N TO-79 gold-capped tubes, old used Passed the test
Update the latest spot, you can circle the VGS you want, and friends who want more quantity can negotiate the price.
1: Only 1 piece of old 2SK180 USD: 50
2: Only 1 piece of old 2SK181 USD: 50
3: Old THF-51N THF51N THF51N and THF-51S functions the same. Friends in need, please see the picture below. It is cheap For sale, tested, please browse if there are data records, and there is an exact match. 1 piece USD: 50 China Post USD: 12-20
1: Only 1 piece of old 2SK180 USD: 50
2: Only 1 piece of old 2SK181 USD: 50
3: Old THF-51N THF51N THF51N and THF-51S functions the same. Friends in need, please see the picture below. It is cheap For sale, tested, please browse if there are data records, and there is an exact match. 1 piece USD: 50 China Post USD: 12-20
Yet another MEH Synergy project
- By Speedysteve7
- Multi-Way
- 229 Replies
Time to fess up, I've been reading and learning about the Danley originals and inspired clones for a good while now.
So much info and help here and online.
Very inspiring.
I decided to make one, to start with.
Lots of measuring what's online, drawing and scaling and plenty of thinking.
I took the plunge and decided to make a prototype.
As this is for a domestic room test, I decided to to go with one 12" woofer and two 5" MIDs + HF compression driver.
Flares on and rounding / smoothing started.
Primed to help see the imperfections.
I spend a lot of time ensuring a smooth throat transition from perfect 1" to 4 sided conical.
I've always found this to be critical on my other horn creations -
12 sided conicals, tractrix and Le Cléac'h diy horns.
Drivers from the top down:
HF; BMS 4550 - need to introduce this one🙂
MF; 2 X Celestion 5" sealed back.
Not the Misco ones I would have liked!
I did message Misco but didn't hear back.. yet.
LF; single Eminence Kappa 12A
These have served me very well in my mid bass 100Hz to 400Hz hyperbolic horns. No need to buy more either.
This was a trial fitting
I decided the conical to flares needed more smoothing..
Happier with that.
Having used cheap as chips chipboard, I decided to sheet them with some leftover sound deadening sheeting.
Result, pretty dead!
These won't be going very loud, so should be good.
Making the rear enclosure for the bass reflex part took time.
Overall quite compact and easy to carry the pieces up to my music loft room.
When compared to all the hardware of the other horns.
3 round horns and 1 tweeter replaced by 1 synergy!
I then did a quick dial in, very easy to do in Najda DSP.
Set up the X/Os, quick time / phase alignment to the tapped horn.
Dialed in the SPLs.
Notch PEQ on the BMS 4550 at 2200Hz
I will spend much time dialling in, trying different X/O slopes. Aiming for nice phase plot.
Quick setup plot from the listening position.
(Ignore the 25Hz bump, that's the tapped horn - it's the way I like it, gives huge scale and energy to church organ and electronica etc 🙂).
The trail off of HF really isn't noticeable from the chair! There's relatively speaking plenty of HF action, for me!
So, how did it compare?
Very interesting!
Listening in mono, one side to the other, the sound coverage of the room is amazing.
You get the pretty much the same sound no matter where you are!
Not so the old 5 way side! It's the listening chair, or nowhere!
I had to boost the mid bass SPL to get better balance and more drive, to my taste. The Crown amp and Kappa 12A are up to the job.
It's not a bad sound at all!
I could tell by how easy it was to dial in and how flat the individual drivers frequency responses were, that it would be promising from the off.
Funny how you can tell something will sound okay from hearing the frequency sweeps - when you've heard enough I guess🙂
Surprising balanced and detailed overall impression.
Mid bass is good, not slow or bloated, fast and nice timbre.
I guess the mid drivers are not run in?
They sound pretty good though. Not in your face, or too passive.
The HF driver, do compression drivers run in?
It actually competes with the 5 way side very well.
I would like to build a SM60F style next..
Even more hifi room friendly!
Just got to figure out an elegant way to channel HF / MF from the coaxial driver.
I will now spend time dialling and positioning, whist I plot/ plan the SM60 alike.
Questions: should the woofer sealed rear chamber volume be the same if you only use one driver?
What X/O slopes would sound best?
I started with 8th order LF high pass (matches the tapped horn),
4th order all else?
So much info and help here and online.
Very inspiring.
I decided to make one, to start with.
Lots of measuring what's online, drawing and scaling and plenty of thinking.
I took the plunge and decided to make a prototype.
As this is for a domestic room test, I decided to to go with one 12" woofer and two 5" MIDs + HF compression driver.
Flares on and rounding / smoothing started.
Primed to help see the imperfections.
I spend a lot of time ensuring a smooth throat transition from perfect 1" to 4 sided conical.
I've always found this to be critical on my other horn creations -
12 sided conicals, tractrix and Le Cléac'h diy horns.
Drivers from the top down:
HF; BMS 4550 - need to introduce this one🙂
MF; 2 X Celestion 5" sealed back.
Not the Misco ones I would have liked!
I did message Misco but didn't hear back.. yet.
LF; single Eminence Kappa 12A
These have served me very well in my mid bass 100Hz to 400Hz hyperbolic horns. No need to buy more either.
This was a trial fitting
I decided the conical to flares needed more smoothing..
Happier with that.
Having used cheap as chips chipboard, I decided to sheet them with some leftover sound deadening sheeting.
Result, pretty dead!
These won't be going very loud, so should be good.
Making the rear enclosure for the bass reflex part took time.
Overall quite compact and easy to carry the pieces up to my music loft room.
When compared to all the hardware of the other horns.
3 round horns and 1 tweeter replaced by 1 synergy!
I then did a quick dial in, very easy to do in Najda DSP.
Set up the X/Os, quick time / phase alignment to the tapped horn.
Dialed in the SPLs.
Notch PEQ on the BMS 4550 at 2200Hz
I will spend much time dialling in, trying different X/O slopes. Aiming for nice phase plot.
Quick setup plot from the listening position.
(Ignore the 25Hz bump, that's the tapped horn - it's the way I like it, gives huge scale and energy to church organ and electronica etc 🙂).
The trail off of HF really isn't noticeable from the chair! There's relatively speaking plenty of HF action, for me!
So, how did it compare?
Very interesting!
Listening in mono, one side to the other, the sound coverage of the room is amazing.
You get the pretty much the same sound no matter where you are!
Not so the old 5 way side! It's the listening chair, or nowhere!
I had to boost the mid bass SPL to get better balance and more drive, to my taste. The Crown amp and Kappa 12A are up to the job.
It's not a bad sound at all!
I could tell by how easy it was to dial in and how flat the individual drivers frequency responses were, that it would be promising from the off.
Funny how you can tell something will sound okay from hearing the frequency sweeps - when you've heard enough I guess🙂
Surprising balanced and detailed overall impression.
Mid bass is good, not slow or bloated, fast and nice timbre.
I guess the mid drivers are not run in?
They sound pretty good though. Not in your face, or too passive.
The HF driver, do compression drivers run in?
It actually competes with the 5 way side very well.
I would like to build a SM60F style next..
Even more hifi room friendly!
Just got to figure out an elegant way to channel HF / MF from the coaxial driver.
I will now spend time dialling and positioning, whist I plot/ plan the SM60 alike.
Questions: should the woofer sealed rear chamber volume be the same if you only use one driver?
What X/O slopes would sound best?
I started with 8th order LF high pass (matches the tapped horn),
4th order all else?
2 ways desktop speakers (easy and powerful)
- By NickCool2000
- Multi-Way
- 6 Replies
Hi everyone,
This project turned out to be quick, straightforward, and with a great outcome—so I figured it was worth sharing.
These desktop speakers deliver a clean, confident sound. They handle plenty of power, are solidly built, and easy to put together. The goal was to upgrade the speakers I use with my PC (driven by a TPA3116 amp) for listening to music, voice, and video—so clarity was key. That said, with a bit of EQ, they’re also more than capable of livening up a party.
I went with Faital drivers, partly because they’re readily available here in Buenos Aires, but also because they come with reliable and comprehensive specs.
I kept the crossover design simple—a first-order Butterworth filter set at 1kHz—and it did the trick. Of course, you can always tweak the resistor values if you want to shape the top end a bit more.
This project turned out to be quick, straightforward, and with a great outcome—so I figured it was worth sharing.
These desktop speakers deliver a clean, confident sound. They handle plenty of power, are solidly built, and easy to put together. The goal was to upgrade the speakers I use with my PC (driven by a TPA3116 amp) for listening to music, voice, and video—so clarity was key. That said, with a bit of EQ, they’re also more than capable of livening up a party.
I went with Faital drivers, partly because they’re readily available here in Buenos Aires, but also because they come with reliable and comprehensive specs.
I kept the crossover design simple—a first-order Butterworth filter set at 1kHz—and it did the trick. Of course, you can always tweak the resistor values if you want to shape the top end a bit more.
XSim, VituixCAD vs ai
- Software Tools
- 12 Replies
I'm curious about your thoughts.
When designing a speaker network, what do you think about using XSim or VituixCAD compared to using AI assistance?
XSim and VituixCAD are excellent for precise simulation, while AI can suggest design directions, ideas, and optimizations.
For Sale SIT amplifier
- By schultzsch
- Swap Meet
- 16 Replies
Hello,
So I had this Adcom 5802 from which I got the enclosure, the transformer, the big caps in the ps filter(which were recently replaced and measure 4miliohm and 22000u) and the small power supply that controls the big toroid.
So I decided to use the enclosure to build a nice 20w/8r and 27w/4r.
The amp uses the Stasis Fe as a front end, accepts rca and xlr inputs and has a voltage gain of 10x.
The output stage is similar to the one in Sit 5 and uses same working principle.
Here how the pcbs look. There is the main pcb with the output stage and a slave pcb with the front end.
The amp looks like this
From outside(good shape cosmetically, can send more photos using direct messaging)
And here the inside
A few more photos with the amp
You will notice that I used the small 12v power supply to control the big toroid from the front switch.
I installed some temperature sensors connected directly to each sit capsule to monitor the temp meanwhile testing. If needed I can leave these in place else they can be removed though it won’t change a thing soundwise.
The sensors will help if you use the amp with improper cooling because once the capsule reaches 75C they will turn off the main trafo.
Here are a few thd graphs
1w/4r
1w/8r
27w/4r
20w/8r
The power supply is dual mono, each channel is powered from its own winding from the trafo.
Initially the Adcom trafo gave too much output voltage which I had to lower a bit so I took the trafo at a trafo winding factory near my town so they rewinded completely the secondaries. When I got the transformer back it made a bit of noise so I have to return it back for a 2nd attempt. Now the noise got lower but there still is some. I will askthem to make another attempt.
I didn`t get a new trafo because I wanted to be able to use the amp at 120/240v like it iniatially was designed and still can be used.
In the meantime that the trafo was at the factory I used smps power supplies with great success and practically no noise and very low cost(320w meanwell)
Because I want to go ahead with my projects I need to pull some funds from somewhere and this amp will save me this time. So don`t have other funds to put a new trafo inside.
I was thinking at the following..
I was planning to ask 1300e for the amp it the trafo would have worked as expected.
A trafo for this amp is around 250e at Toroidiy so what about 1000e for the amp as it is?
I will send it with the actual trafo.
The amp weights a bit more than 25kg. I can ship it in the UK and some countries in the EU(Austria, Italy, Germany, Belgium and probably others) at 1.2 pounds/euros. For the UK no custom taxes will be implied. So in these cases the shipping will be quite cheap.
If you have a pair of field coil drivers that that you want to trade I am all eyes and ears 🙂
As for the sound.. what I can tell is that it`s explosive! I built a few sit amps but none sounded so powerful like this one.
Edit:
Somebody asked how h2 looks so here we go
10w/8r
10w/4r
So I had this Adcom 5802 from which I got the enclosure, the transformer, the big caps in the ps filter(which were recently replaced and measure 4miliohm and 22000u) and the small power supply that controls the big toroid.
So I decided to use the enclosure to build a nice 20w/8r and 27w/4r.
The amp uses the Stasis Fe as a front end, accepts rca and xlr inputs and has a voltage gain of 10x.
The output stage is similar to the one in Sit 5 and uses same working principle.
Here how the pcbs look. There is the main pcb with the output stage and a slave pcb with the front end.
The amp looks like this
From outside(good shape cosmetically, can send more photos using direct messaging)
And here the inside
A few more photos with the amp
You will notice that I used the small 12v power supply to control the big toroid from the front switch.
I installed some temperature sensors connected directly to each sit capsule to monitor the temp meanwhile testing. If needed I can leave these in place else they can be removed though it won’t change a thing soundwise.
The sensors will help if you use the amp with improper cooling because once the capsule reaches 75C they will turn off the main trafo.
Here are a few thd graphs
1w/4r
1w/8r
27w/4r
20w/8r
The power supply is dual mono, each channel is powered from its own winding from the trafo.
Initially the Adcom trafo gave too much output voltage which I had to lower a bit so I took the trafo at a trafo winding factory near my town so they rewinded completely the secondaries. When I got the transformer back it made a bit of noise so I have to return it back for a 2nd attempt. Now the noise got lower but there still is some. I will askthem to make another attempt.
I didn`t get a new trafo because I wanted to be able to use the amp at 120/240v like it iniatially was designed and still can be used.
In the meantime that the trafo was at the factory I used smps power supplies with great success and practically no noise and very low cost(320w meanwell)
Because I want to go ahead with my projects I need to pull some funds from somewhere and this amp will save me this time. So don`t have other funds to put a new trafo inside.
I was thinking at the following..
I was planning to ask 1300e for the amp it the trafo would have worked as expected.
A trafo for this amp is around 250e at Toroidiy so what about 1000e for the amp as it is?
I will send it with the actual trafo.
The amp weights a bit more than 25kg. I can ship it in the UK and some countries in the EU(Austria, Italy, Germany, Belgium and probably others) at 1.2 pounds/euros. For the UK no custom taxes will be implied. So in these cases the shipping will be quite cheap.
If you have a pair of field coil drivers that that you want to trade I am all eyes and ears 🙂
As for the sound.. what I can tell is that it`s explosive! I built a few sit amps but none sounded so powerful like this one.
Edit:
Somebody asked how h2 looks so here we go
10w/8r
10w/4r
SSLV1.1 builds & fairy tales
- By Salas
- Power Supplies
- 4785 Replies
Here's a building thread for the SSLV1.1 BiB PCB reg. Its to discuss builds, ask questions, tell stories.😀
The absolutely must read before build PDF instructions link for download is: BIBguideRev2. Good luck!
That guide is also attached in a somewhat lower resolution compressed file below.
''Lazybutt'' Fred's Excel calc attachment to help you set values has been added on 1/14/12
And a useful wiring configuration tip is: When and how to connect the reg in two wire mode
Successor new design (2018): Salas SSLV1.3 UltraBiB shunt regulator
The absolutely must read before build PDF instructions link for download is: BIBguideRev2. Good luck!
That guide is also attached in a somewhat lower resolution compressed file below.
''Lazybutt'' Fred's Excel calc attachment to help you set values has been added on 1/14/12
And a useful wiring configuration tip is: When and how to connect the reg in two wire mode
Successor new design (2018): Salas SSLV1.3 UltraBiB shunt regulator Sony DVP-S7700 Analog audio board upgrade with Burson V7 Opamps
- By dolsey01
- Digital Source
- 1 Replies
I have been using a Sony DVP-S7700 as a transport connected to my Music Hall 25.2 Dac which has some slight mods, including Burson V7 Vivid opamps and a Gold Lion 12AU7 tube. Burson has been kind enough to provide me with samples for a new project to mod my DVP-S7700 and install DIP 8 sockets and replace the OPA2134 factory opamps.
Phase one has been completed, removing the soldered OPA2134 and replacing them with DIP 8 sockets.
Phase two is waiting on some DIP extensions from Burson, it's too tight to install the V7 opamps due to the location of some capacitors. This will hopefully make it easier to swap without having to remove the analog audio board every time.
Please follow along for future comparisons between the analog audio board with the Burson opamps compared to the external Music Hall 25.2 Dac using the Sony as a transport connected through CoAx. I will also be comparing the older V6 Classic, to the V7 and OEM OPA2134.
Phase one has been completed, removing the soldered OPA2134 and replacing them with DIP 8 sockets.
Phase two is waiting on some DIP extensions from Burson, it's too tight to install the V7 opamps due to the location of some capacitors. This will hopefully make it easier to swap without having to remove the analog audio board every time.
Please follow along for future comparisons between the analog audio board with the Burson opamps compared to the external Music Hall 25.2 Dac using the Sony as a transport connected through CoAx. I will also be comparing the older V6 Classic, to the V7 and OEM OPA2134.
Xtant X604 burning resistors
I am back again with the same amplifier, my lovely Xtant X604.
Last time I was able to recover the functionality with your help (water leak). Now I discovered that my front left tweeter is not working and making strange sound (I am bi-amping the front end). So I popped the cover off, inspected for water leaks - didn't find any but found 2 burned resistors. One is R111, the other one has no reference designator but since it sits between R108 and R110 it is likely R109. Also did a search before making this post and found the schematic for X603 posted by Perry Barin. Wonder if Perry or someone else has the same schematic without additional markings written over it. Perry was wonderful helping me fix the amp last time I had a short due to water leak that formed crater in pcb (2021). Will try to dig into this tomorrow.
Last time I was able to recover the functionality with your help (water leak). Now I discovered that my front left tweeter is not working and making strange sound (I am bi-amping the front end). So I popped the cover off, inspected for water leaks - didn't find any but found 2 burned resistors. One is R111, the other one has no reference designator but since it sits between R108 and R110 it is likely R109. Also did a search before making this post and found the schematic for X603 posted by Perry Barin. Wonder if Perry or someone else has the same schematic without additional markings written over it. Perry was wonderful helping me fix the amp last time I had a short due to water leak that formed crater in pcb (2021). Will try to dig into this tomorrow.
Attachments
FET's transfer curve analyser aka locky_z to handy numbers
- By ripson
- Software Tools
- 0 Replies
For my needs I created this little PowerShell tool and I wanted to share it. It is made to help picking FETs based on their transfer curves.
Instead of just looking at the curves, it can calculate some basic numbers like how linear the device is across the range.
It’s mainly for people who want to select FETs by linearity, transconductance, and want an easier way to spot which FETs behave nicely, meaning more consistent gm and fewer surprises.
What it does:
PS. How to run it? Unpack it and in Windows just right click and "Run with PowerShell", for security reason please ALWAYS check the script or any other modified for any suspicious code, it is a text based file.
Instead of just looking at the curves, it can calculate some basic numbers like how linear the device is across the range.
It’s mainly for people who want to select FETs by linearity, transconductance, and want an easier way to spot which FETs behave nicely, meaning more consistent gm and fewer surprises.
What it does:
- Reads your transfer curve data (like from a Locky_Z tracer)
- Calculates transconductance (gm) at different points or average within the curve
- Gives a quick idea of how "linear" the FET really is (from 0 to 1 where 1 is a straight line)
- Makes it easier to pick better parts without having to guess from the graphs
PS. How to run it? Unpack it and in Windows just right click and "Run with PowerShell", for security reason please ALWAYS check the script or any other modified for any suspicious code, it is a text based file.
Pass F4 Investigations
I will just do SPICE simulations. Will be no building 🙂
Pass F4 is an intriguing amplifier. Can be called a high current power buffer.
To begin with I will be focusing on the original F4 as can be seen in service manual.
I know there are some modified versions, but they have their own life.
The original version can be seen in my image.
I have stripped off the JFET input stage, because most preamplifiers have no problem with F4 input impedance.
Some facts I have found out:
Gain: 0.97
Input impedance: ~8 kOhm
Distortion THD:
01 W: 0.003%
02 W: 0.004%
04 W: 0.007%
10 W: 0.013%
20 W: 0.028%
Pass F4 is an intriguing amplifier. Can be called a high current power buffer.
To begin with I will be focusing on the original F4 as can be seen in service manual.
I know there are some modified versions, but they have their own life.
The original version can be seen in my image.
I have stripped off the JFET input stage, because most preamplifiers have no problem with F4 input impedance.
Some facts I have found out:
Gain: 0.97
Input impedance: ~8 kOhm
Distortion THD:
01 W: 0.003%
02 W: 0.004%
04 W: 0.007%
10 W: 0.013%
20 W: 0.028%
For Sale XA252 PoP R1
- By schultzsch
- Swap Meet
- 73 Replies
I have for sale a few more PoPs, R1 this time with better layout and performance.
These can be tuned to have more or less flavor so it can suit all tastes by changing a few key components in the front end. Depending on your taste you can mention what exactly you want, less flavor meaning less thd.
From the strongest flavored to the light flavored at some power levels the thd is half.
Please see the new thd graphs at the bottom of the post where I compare the same module setup in 2 different ways.
Since some time I go ahead with the Xa252 PoP being the reference amp in my system.
It can work from +/-16v to +/-24.5v. Bias is preset at 1.4a.
The schematic looks like this
Stable as before when handling square waves
The new pcb has same drill hole pattern as R0
And here some thd measurements
All modules are tested and working. If no preference for the thd the modules will ship with the stronger flavor.
Later edit:
I am adding a crc psu pcb together with the modules for the same price.
Price for 2 channels and the crc psu pcb 160€
Later edit:
Someone said he uses a 5U400 enclosure for his builds (which is quite big) and is able to take 1.8A bias at +/-24V. So the user wanted to use the modules at a higher bias(1.8A) than the 1.4A as I set them.
With a higher bias for the output stage you will get more power output in class a(which you have plenty already with 1.4a bias) but also a bit more thd at high output power. So I think this time it`s better to keep it at 1.4A.
The maximum bias that can be set for the PoP modules is 1.6A so I took the measurements here, didn`t bother to modify the tested module to go to 1.8A. It isn`t really needed for the PoP.
These can be tuned to have more or less flavor so it can suit all tastes by changing a few key components in the front end. Depending on your taste you can mention what exactly you want, less flavor meaning less thd.
From the strongest flavored to the light flavored at some power levels the thd is half.
Please see the new thd graphs at the bottom of the post where I compare the same module setup in 2 different ways.
Since some time I go ahead with the Xa252 PoP being the reference amp in my system.
It can work from +/-16v to +/-24.5v. Bias is preset at 1.4a.
The schematic looks like this
Stable as before when handling square waves
The new pcb has same drill hole pattern as R0
And here some thd measurements
All modules are tested and working. If no preference for the thd the modules will ship with the stronger flavor.
Later edit:
I am adding a crc psu pcb together with the modules for the same price.
Price for 2 channels and the crc psu pcb 160€
Later edit:
Someone said he uses a 5U400 enclosure for his builds (which is quite big) and is able to take 1.8A bias at +/-24V. So the user wanted to use the modules at a higher bias(1.8A) than the 1.4A as I set them.
With a higher bias for the output stage you will get more power output in class a(which you have plenty already with 1.4a bias) but also a bit more thd at high output power. So I think this time it`s better to keep it at 1.4A.
The maximum bias that can be set for the PoP modules is 1.6A so I took the measurements here, didn`t bother to modify the tested module to go to 1.8A. It isn`t really needed for the PoP.
-
Poll
Cello Palette Style EQ Design (was High End Tone Control)...
- By ThorstenL
- Analog Line Level
- 460 Replies
Folks,
At the other thread I noticed interest in what may be called a "functional clone" of the Cello palette. Please review the High End Tone Control thread for background information and the options discussed:
http://www.diyaudio.com/forums/analog-line-level/194119-high-end-tone-control.html
The Palette is best described as a Stereo Mastering EQ designed for easy and intuitive use by non-engineers (most EQ's need operators with at least two degrees and many years of experience to get suitable results). One way to describe the actions of the six controls of the Palette approximately is:
Bass [20Hz]
Drum [120Hz]
Lower Voice [500Hz]
Presence [2Khz]
Rasp [5KHz]
Air [20KHz]
Control ranges are 'weighted' so that any changes for a given rotation in for example the "presence" band are much smaller than the "bass" band, relating directly to the behaviour of the human hearing. The Palette has possibly more adjustment range than is beneficial and due to a number of factors a true clone is jut not a sensible option nor is it necessary.
Here the original:
In principle we can realise something that follows most of the Palette design brief using any technology we care to apply, so much is established.
However "Vita brevis, ars longa" dictate that we cannot spend time, effort and money on making a Palette functional clone with each and every available technology and then to let everyone choose which design suits them best.
So for starters we set the following outline for the actual EQ function:
Centre frequencies:
20Hz +/- 12 ... 18dB
120Hz +/- 6 ... 9dB
500Hz +/- 3 ... 5.5dB
2KHz +/- 3 ... 5.5dB
5KHz +/- 6 ... 9dB
20KHz +/- 12 ... 18dB
We can make bands somewhat adjustable using switches if desired.
Adjustment range is open to some debate as well.
Controls should be able to use generally available potentiometers but can be implemented also with rotary switches.
If we limit ourselves to 24-Pole switches (actually 23 Poles usable) this gives us +/- 11 positions for boost/cut.
This suggests 0.4dB steps for the innermost bands (so +/- 4.4dB), 0.8dB steps for the intermediate bands (so +/- 8.8dB) and 1.2dB steps for the extreme bands (so +/- 13.2dB).
If these items are agreeable we can proceed to select the electronic circuitry, here is where the poll comes in. If you are interested in this analogue (re)mastering EQ project, please vote in the poll on the technology to be used. the poll is multi-choice to perhaps vote 1st & 2nd choice...
Ciao T
At the other thread I noticed interest in what may be called a "functional clone" of the Cello palette. Please review the High End Tone Control thread for background information and the options discussed:
http://www.diyaudio.com/forums/analog-line-level/194119-high-end-tone-control.html
The Palette is best described as a Stereo Mastering EQ designed for easy and intuitive use by non-engineers (most EQ's need operators with at least two degrees and many years of experience to get suitable results). One way to describe the actions of the six controls of the Palette approximately is:
Bass [20Hz]
Drum [120Hz]
Lower Voice [500Hz]
Presence [2Khz]
Rasp [5KHz]
Air [20KHz]
Control ranges are 'weighted' so that any changes for a given rotation in for example the "presence" band are much smaller than the "bass" band, relating directly to the behaviour of the human hearing. The Palette has possibly more adjustment range than is beneficial and due to a number of factors a true clone is jut not a sensible option nor is it necessary.
Here the original:
In principle we can realise something that follows most of the Palette design brief using any technology we care to apply, so much is established.
However "Vita brevis, ars longa" dictate that we cannot spend time, effort and money on making a Palette functional clone with each and every available technology and then to let everyone choose which design suits them best.
So for starters we set the following outline for the actual EQ function:
Centre frequencies:
20Hz +/- 12 ... 18dB
120Hz +/- 6 ... 9dB
500Hz +/- 3 ... 5.5dB
2KHz +/- 3 ... 5.5dB
5KHz +/- 6 ... 9dB
20KHz +/- 12 ... 18dB
We can make bands somewhat adjustable using switches if desired.
Adjustment range is open to some debate as well.
Controls should be able to use generally available potentiometers but can be implemented also with rotary switches.
If we limit ourselves to 24-Pole switches (actually 23 Poles usable) this gives us +/- 11 positions for boost/cut.
This suggests 0.4dB steps for the innermost bands (so +/- 4.4dB), 0.8dB steps for the intermediate bands (so +/- 8.8dB) and 1.2dB steps for the extreme bands (so +/- 13.2dB).
If these items are agreeable we can proceed to select the electronic circuitry, here is where the poll comes in. If you are interested in this analogue (re)mastering EQ project, please vote in the poll on the technology to be used. the poll is multi-choice to perhaps vote 1st & 2nd choice...
Ciao T
Open Source Monkey Box
This is a long thread with many twists and dead ends. Before diving in, take a look a this first:
-----------------------------------------------------------
Following up on the earlier Open Source Speaker thread (part I and part II) I am starting a new thread to discuss the develpment of the "Open Source Monkey Coffin".
Here's an update of my earlier Monkey Coffin ideas. Sorry it's so long.
POINTS OF DEPARTURE (as I see them):
MY IMPLEMENTATION IDEAS (I admit these are partially biased by my own preferences, because I need some motivation to actually put some work into this):
NEXT STEPS AND QUESTIONS (everyone has his/her own approach to loudspeaker design, but here's my suggestion):
---------------------------------------------
Notes and updates:
Important note 31 Oct. 2019: DIYers may profit from this open-source project for their own private purposes, for example by building and enjoying a copy of the Open Source Monkey Coffin speaker. Please do not use the information developed in this open source project on a larger scale (for example by selling speakers based on the Open Source Monkey Coffin design or substantial parts of it) without written permission.
Note 4 Oct. 2018: This project has received financial support from LORDSANSUI, Paul Vancluysen, George Wright, KaffiMann, Charles Bueche, zimmer64, John Barbor, and others (anonymous) here. Thank you!
Note 10 Nov. 2019: This project has come a very long way, and the OSMC design is now completed. The design goals have been largely met, but some of the early implementation ideas have changed a bit along the way (x-over topology, woofer size, tweeter details). The full documentation of the OSMC design is here: https://github.com/mbrennwa/osmcdoc
Note 4 Oct. 2018 and 18 Nov. 2019: Final choice of drivers:
Note 18 Nov. 2019: Final enclosure is in post 925 (drawings) and post 930 (photos, showing stuffing).
Note 18 Nov. 2019: Final x-over is in post 931.
Note 18 Nov. 2019: The polar response diagrams (horizontal and vertical) are in post 895.
Note 18 Nov. 2019: The power response is in post 901.
Note 18 Nov. 2019: The electrical impedance is in post 900.
Note 19 Feb. 2020: A bunch of graphs with test results as compiled from the documentation on GitHub (on-axis SPL response, step response, polar response, cumulative decay spectrum (CSD) are in post 917.
Note 9 May 2020: If you don't know where to look, here's a list with some shops and retailers for OSMC parts:
- The documentation files of the finished Open Source Monkey Coffin loudspeaker. I am (trying to) keep this up to date!
- The notes at the end of this post, which have some useful hints to navigate the thread.
-----------------------------------------------------------
Following up on the earlier Open Source Speaker thread (part I and part II) I am starting a new thread to discuss the develpment of the "Open Source Monkey Coffin".
Here's an update of my earlier Monkey Coffin ideas. Sorry it's so long.
POINTS OF DEPARTURE (as I see them):
- The first poll says it should be a three way, and it's okay to cost more than $500 per box.
- The second poll says that the Monkey Box should be "amplifier friendly" (work well with ACAs or small tube amps, etc.), and it should not be too big (not more than 60-80 L).
- The speaker should be straight forward to make for DIY novices (we don't want to scare them, we want them to run to the hardware shop and build stuff on their kitchen table). There is no point in designing for expert builders, because they will design their own speakers anyway.
MY IMPLEMENTATION IDEAS (I admit these are partially biased by my own preferences, because I need some motivation to actually put some work into this):
- The box shoud be easy enough to make on a kitchen table. Dimensions roughly 30 x 65 x 30 cm or so (will depend on the requirements of the drivers and box tuning).
- For "weak amp compatibility" I set the efficiency target to 92 dB/2.83V/1m, with bass extension to 45 Hz (-3 dB). Achieving this will not be very easy.
- The impedance curve should be flatish and qualify as "8 Ohm". This means we can't "cheat" with the efficiency target by using low-impedance drivers.
- Use high-quality drivers/parts with the right tech specs for the task. The look of the drivers has to be "right" for a HiFi system in a home environment, but is second priority after the tech specs (people may not want to build a speaker that does not look "right").
- Woofer: The woofer will likely be the limiting factor that determines the size/bass-extension/efficiency compromise. I guess a 10" unit would be the right choice here. The earlier threads already mentioned a few units that might be interesting for this design (Fane Sovereign Pro 10-300SC, Ciare FXE 10-2.5, Volt BM251.3, some Beymas, etc.). We'll have to look at this some more.
- Midrange: Needs to keep up with the SPL requirements, so many of the conventional "HiFi" midranges are out. I have some experience with the ATC SM75-150 dome, which is VERY good, expensive, and not available to DIYers anymore. When ATC stopped selling to the DIY market, Volt released the VM752 dome, which is a very good clone of the ATC driver. I really want to use the Volt VM752 dome. It can be used from its fs (400 Hz) up to about 3 kHz or so.
- Tweeter: There are many good tweeters out there. I am a big fan of Be dome tweeters (ScanSpeak D3004/6640, SB Acoustics Satori TW29BN). I also read a bit about waveguides, which do good things. They help with matching the dispersion of the tweeter to the midrange, they reduce the effects of baffle diffraction, they increase the on-axis efficiency, and they reduce non-linear distortion of the tweeter (by reducing the drive voltage for a given SPL). At the moment I can't think of a reason why we should not use a waveguide.
- Cross over filters: the x-over frequencies will depend quite a bit on the driver choices. However, if possible, I like to set the woofer/midrange x-over frequency such that it fits the baffle-step centre frequency. This makes it easier to compensate the baffle step by fiddling with the woofer SPL vs midrange SPL. If the drivers allow, I like using 6 dB/octave filters because it's easier to get the time-domain response of the loudspeaker right. In my experiments, my ears preferred 6 dB filters over 12 dB filters.
- I will openly admit that costs are not my first priority. If the right parts cost a lot of money and there are no alternatives, so be it. The earlier threads indicated that it's ok if the parts cost is more than $500 per speaker. Some said $1000. My priority is to make this a very good speaker, and suitable parts may cost a bit of money. In the end, there will always be substantial flexibility with costs related to x-over parts and enclosure materials + finishing.
NEXT STEPS AND QUESTIONS (everyone has his/her own approach to loudspeaker design, but here's my suggestion):
- In the first step we'll have to narrow down the driver choices. This will be a forward-and-backward process between driver suggestions and model runs using these drivers, always keeping the design targets in mind. I'd suggest choosing a woofer first, because that will define the box size, bass extension, and sensitivity. Let's say the midrange is set (yes, you are allowed to complain, but... ). The tweeter comes last.
Question: What input data do we need for these model runs? Do we need actual measurements of the drivers in their baffle/box? I am not big with modelling tools, and I tend to replace detailed model runs by measurements from prototypes. Others might be more efficient than this by using their modelling tools. - The second step is to build an actual prototype. Now we need money to buy parts. If the design is still attractive to me (i.e., it's something that I'd like to build and use myself), I'd be willing to put in some money and go for it. I could also do measurements.
Question: How will the funding work? Anyone experienced with raising and managing money for open source projects? Anyone willing to put some cash on the table? Who will manage the money, and how? - The third step is to tweak the prototype. Again, this will be another forward-and-backward process. And we may need more money.
---------------------------------------------
Notes and updates:
Important note 31 Oct. 2019: DIYers may profit from this open-source project for their own private purposes, for example by building and enjoying a copy of the Open Source Monkey Coffin speaker. Please do not use the information developed in this open source project on a larger scale (for example by selling speakers based on the Open Source Monkey Coffin design or substantial parts of it) without written permission.
Note 4 Oct. 2018: This project has received financial support from LORDSANSUI, Paul Vancluysen, George Wright, KaffiMann, Charles Bueche, zimmer64, John Barbor, and others (anonymous) here. Thank you!
Note 10 Nov. 2019: This project has come a very long way, and the OSMC design is now completed. The design goals have been largely met, but some of the early implementation ideas have changed a bit along the way (x-over topology, woofer size, tweeter details). The full documentation of the OSMC design is here: https://github.com/mbrennwa/osmcdoc
Note 4 Oct. 2018 and 18 Nov. 2019: Final choice of drivers:
- Tweeter: ScanSpeak R2904/7000 ring radiator (post 295 and follow ups) with a custom waveguide as described in post 881 (available via group buy or by DIY 3D printing or CNC machining).
- Midrange: Volt VM752 3" textile dome
- Woofer: FaitalPRO 12PR320 12" paper cone (see post 162 and post 244).
Note 18 Nov. 2019: Final enclosure is in post 925 (drawings) and post 930 (photos, showing stuffing).
Note 18 Nov. 2019: Final x-over is in post 931.
Note 18 Nov. 2019: The polar response diagrams (horizontal and vertical) are in post 895.
Note 18 Nov. 2019: The power response is in post 901.
Note 18 Nov. 2019: The electrical impedance is in post 900.
Note 19 Feb. 2020: A bunch of graphs with test results as compiled from the documentation on GitHub (on-axis SPL response, step response, polar response, cumulative decay spectrum (CSD) are in post 917.
Note 9 May 2020: If you don't know where to look, here's a list with some shops and retailers for OSMC parts:
- diyAudio group buy for the OSMC tweeter waveguides
- Falcon (Europe): Scan 2904 tweeter, Volt VM752 midrange driver, x-over parts, etc.
- Solen (Canada, US): Scan 2904 tweeter, Volt VM752 midrange driver, x-over parts, etc.
- Audiohobby (free shipping everywhere!?): Scan 2904 tweeter, x-over parts, bass-reflex ports
- US Speaker (US): Faital 12PR320 woofer
- Blue Aran (Europe): Faital 12PR320 woofer
- Acoustical Surfaces (US): Melamine foam. Contact person: Tom Ewert +1 (952) 466-8229. They also sell in small quantities!
- Ebay: Melamine foam
- Buttinette (yes...): lambs wool
- Deer Creek Audio: Custom speaker stands
T25A Simple Waveguide Profile
Recently @hifijim started a new project involving the Bliesma T25A tweeter, as part of the discussion I offered to see if a simple small waveguide could be simulated. Jim has decided against the use of a waveguide for perfectly understandable reasons. I don't have a T25A myself and so I haven't created a printable model of the profile to test. There was some interest shown in that thread for the waveguide profile to be posted in a separate thread, so here it is.
The Bliesma aluminium drivers are very tall and require a different profile than many modern waveguides aim for in order to avoid ugly cancellations in the very high frequency range. I tried a number of variations on a theme in Ath to see what I could get, but it was not easy to find a profile that did not have some kind of downside to it.
I've simulated many CAD drawn profiles for the T25A in the past and so that is the route I tried next. This should hardly come as news or any kind of discovery as it has been known for a long time that dome tweeters almost always work in a waveguide that uses a section of a circular radius for it's profile. This does not have as dramatic of an effect on the directivity as OS or other proflies can have, but it is that property of not doing too much that allows it to work almost as a universal profile.
It is very simple to draw in a CAD program. I use Fusion and will outline how to use that program to draw it, but the principal could be applied to any other program.
This waveguide is thin at 6mm and relatively small at 104mm in diameter, similar to a standard tweeter faceplate.
I first draw a circle on the XZ plane that represents the throat, in this case it is 29.7mm, using a slightly higher value of 30mm might be preferable depending on the properties of the material being used to print it.
A new sketch is drawn on the XY plane and the previous circle is projected into this sketch. I draw a construction line straight up at the depth of the waveguide in this case 6mm. I then draw another line across at a 90 degree angle the distance of half the overall diameter in this case 52mm. I then draw a 3 point arc between the projected throat, the outer point of the waveguide profile and the last point just needs to be below the top construction line. With practice you can place it so that tangency is already enforced, but if not use the sketch constraints to make the 3 point arc tangent to the top construction line. You can check if this has worked by extending the arc all the way around until it becomes a circle. In this case the 3 point arc as drawn has a radius of 118.01mm.
The centre point of the circle that is the radius can be see by zooming out the sketch, it is highlighted in yellow
The same principal could be used to create a deeper and larger version of the same thing, there will then be a bigger effect on the overall directivity. This may not be a good thing for the T25A, but if the same ratio is kept between depth and outer diameter I would imagine it could be scaled up without creating negative interference. I haven't tested this so I cannot say exactly what will happen.
I have attached the surface profile as a zipped step file in case anyone wants to use it as is to create their own printable model.
I have attached the simulation outputs based on Jim's baffle. It is more consistent and even than a bare driver and given the size constraints, it fit's on the same diameter as the driver or can be made to. These are non normalized and show 1500 to 15K 0 to 90 degrees in 10 degree steps. The response is pretty much within 1 or 2 dB 0 to 40 degrees and is an even 10 dB down across the board at 90 degrees vs 0.
There is diffraction on axis because this is a BEM model with fully reflective boundaries. All sharp edges and creases on the baffle of which there are a few that are also symmetric show the worst case scenario. A real wooden baffle with smoothed edges and a less symmetric profile would offset this to some extent.
By 15 degrees off axis the response is a pretty smooth downslope
The Bliesma aluminium drivers are very tall and require a different profile than many modern waveguides aim for in order to avoid ugly cancellations in the very high frequency range. I tried a number of variations on a theme in Ath to see what I could get, but it was not easy to find a profile that did not have some kind of downside to it.
I've simulated many CAD drawn profiles for the T25A in the past and so that is the route I tried next. This should hardly come as news or any kind of discovery as it has been known for a long time that dome tweeters almost always work in a waveguide that uses a section of a circular radius for it's profile. This does not have as dramatic of an effect on the directivity as OS or other proflies can have, but it is that property of not doing too much that allows it to work almost as a universal profile.
It is very simple to draw in a CAD program. I use Fusion and will outline how to use that program to draw it, but the principal could be applied to any other program.
This waveguide is thin at 6mm and relatively small at 104mm in diameter, similar to a standard tweeter faceplate.
I first draw a circle on the XZ plane that represents the throat, in this case it is 29.7mm, using a slightly higher value of 30mm might be preferable depending on the properties of the material being used to print it.
A new sketch is drawn on the XY plane and the previous circle is projected into this sketch. I draw a construction line straight up at the depth of the waveguide in this case 6mm. I then draw another line across at a 90 degree angle the distance of half the overall diameter in this case 52mm. I then draw a 3 point arc between the projected throat, the outer point of the waveguide profile and the last point just needs to be below the top construction line. With practice you can place it so that tangency is already enforced, but if not use the sketch constraints to make the 3 point arc tangent to the top construction line. You can check if this has worked by extending the arc all the way around until it becomes a circle. In this case the 3 point arc as drawn has a radius of 118.01mm.
The centre point of the circle that is the radius can be see by zooming out the sketch, it is highlighted in yellow
The same principal could be used to create a deeper and larger version of the same thing, there will then be a bigger effect on the overall directivity. This may not be a good thing for the T25A, but if the same ratio is kept between depth and outer diameter I would imagine it could be scaled up without creating negative interference. I haven't tested this so I cannot say exactly what will happen.
I have attached the surface profile as a zipped step file in case anyone wants to use it as is to create their own printable model.
I have attached the simulation outputs based on Jim's baffle. It is more consistent and even than a bare driver and given the size constraints, it fit's on the same diameter as the driver or can be made to. These are non normalized and show 1500 to 15K 0 to 90 degrees in 10 degree steps. The response is pretty much within 1 or 2 dB 0 to 40 degrees and is an even 10 dB down across the board at 90 degrees vs 0.
There is diffraction on axis because this is a BEM model with fully reflective boundaries. All sharp edges and creases on the baffle of which there are a few that are also symmetric show the worst case scenario. A real wooden baffle with smoothed edges and a less symmetric profile would offset this to some extent.
By 15 degrees off axis the response is a pretty smooth downslope
Attachments
Sell THF-51s 2SK182ES NEW NOS TO-79 SIT V-FET, from Japan TOKIN
- By pras1170
- Vendor's Bazaar
- 336 Replies
Tokin SissySIT THF-51S 2SK182ES MJ21193G MJ21194G MJ21194 LM350K STEEP+ 2N5566 My quotation does not include the handling fee of PAYPAL. Please understand that my quotation does not include the handling fee of paying PAYPAL. Old second-hand 2SK180 K180 appearance
2SB206 B206 2SB205 B205 TO-79 NOS New 2SB206 GE-PNP 80 V 30 A 80 W Quantity: 50PCS 1 piece USD: 65.28
THF-51S 2SK182ES K182ES THF51S SissySIT Friends who need matching. Please leave a message.
The event is only open to BBS friends because each VGS may be different, so for friends who need more, I need to spend a few days testing (need to measure a lot) (because everyone trusts me, so I do it myself. I may spend A few days, because I have other work to do, so I will try to measure the time if I can match them randomly, the amount will be slightly higher if you need to follow VGS -4V or more, hope you all can understand, thank you)
EMAIL :378632242@qq.com SKYPE: Live broadcast: 378632242
2:2SK182ES K182ES NOS NEW v-fet TOKIN from Japan Spot quantity: 50PCS
Matching price: USD: 100/1PCS Thf-51s 2SK182ES features: each has a different sequence number, a different number, a 1-10 number (this is a brand new original, only owned by NOS)
Mica thickness 4.5 (thickest)
Buy thf-51s 2SK182ES for free insulating pads, mica sheets, screws
It can be delivered in a package
(if you do not have a friend who bought thf-51s, you need to pay the postage by yourself. If you need, you can leave a message or send it to my email:378632242@qq.com.)
See the picture:
MJ21193G MJ21194G MJ21194 MJ21193 NOS NEW ON Motorola
1pair=USD:11.56
QTY:80pair
NOS NEW ON MJ21193G MJ21194G MJ21193 MJ21194 250V-16A-200W-4MHZ
LM350K LM350K STEEL
USD:11.57 /1PCS
NEW NOS LM350K LM350K STEEP+ 9712+ I have 50PCS
NSC 8608+ LM350K STEEP+ I have 620PCS
LM350K STEEL NEW NOS NSC TO-3 NEW STEELP+ 0142+ NOS 1PCS USD:11.57 I have 785PCS
Brand NSC
Model LM350k
MAX input voltage 35V
The input voltage of MINIi is 4.2V
Adjust the voltage 1.2-33v direct current
Current 3 a MAX
To encapsulate the to - 3
With the original packaging, packaging foam board is die-cast with the manufacturer's brand. I take it apart. I take it apart. Here is a picture of the tube wafer taken by someone using an electron microscope. It can be seen that the wafer is made in Britain. He who knows is sure to know the goods.
The national semiconductor company makes LM350k. It's not a big problem to play with equipment. The money you really spend is worth it. It is also clear that the foam packaging of this tube is also special and each is individually attached to the tube, rather than the usual one with a cylinder in the middle to separate the surrounding tube. It can directly replace the LM317. This tube can be regarded as the more powerful LM317. The current is twice that of 317, reaching 3A. It is a good choice to supply the machine with sufficient current. Naim power supply board made of high current pipe with low internal resistance, which is a feature pursued by burning friend. Spread knowledge by the way. The quality of the steel tube on the net varies greatly, there are used polish to fill the new, some of the pin resin seal holes are large holes. This kind of imported tubes are all small holes. The color of resin is mainly black, brown, green and red, with few blue. The printed word on the surface of the normal pipe is in the middle, and the position is basically the same. Word is not raised, a bit of brown black, and the surface coating is matte color, won't be very bright, that is polished. Iron tube screw fixation will leave a mark on the screw hole where can distinguish between used and new. This tube is typically quoted at more than 300, which is more expensive than LT's 317.
Refer to the official PDF map for details. You can download the PDF for reference.
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After receiving PayPal, I will ship within 2 business days.
If someone has not received your package within 20 business days of my delivery notice, please let me know.
The shipping and packaging charges for the order are: 1PCS-4PCS=USD: 12.0 In some countries, China post freight only needs USD: 10.0 (Some countries have far-fetched fare, shipping rates may be high+: USD: 2.0)
4PCS-8PCS=USD: 15.0 (some countries are far away, shipping costs may be high+ USD: 2.0)
Buyers in mainland China, Hong Kong and Taiwan can support the payment (support SF Express)
DHL：If the buyer is in a hurry and wants to receive the goods soon, you can choose DHL.
Shipping fee is: 1PCS-4PCS=USD: 29.22
5PCS-10PCS=USD: 43.84
Because the contract with DHL Express, so the freight, gave me the advantage of the price, the freight will be cheaper
The time limit is: 4-5 days to receive
运输政策：请注意，包裹保险不包含在运输条款和条件中指定的运输费用中。请联系我获取保险报价。如果您想为包裹购买保险，请考虑使用更可靠的递送服务提供商，例如 DHL、EMS 或 FEDEX。 PM，给我留言，如果接受条件，请只下订单。谢谢您的理解。
2SK182ES thf-51s 需要一个匹配的朋友
请留言
Pairing就是配对的价格（PM就可以了）
当我不忙的时候，我会测量。下面是2SK182ES的流程。
2SB206 B206 2SB205 B205 TO-79 NOS New 2SB206 GE-PNP 80 V 30 A 80 W Quantity: 50PCS 1 piece USD: 65.28
THF-51S 2SK182ES K182ES THF51S SissySIT Friends who need matching. Please leave a message.
The event is only open to BBS friends because each VGS may be different, so for friends who need more, I need to spend a few days testing (need to measure a lot) (because everyone trusts me, so I do it myself. I may spend A few days, because I have other work to do, so I will try to measure the time if I can match them randomly, the amount will be slightly higher if you need to follow VGS -4V or more, hope you all can understand, thank you)
EMAIL :378632242@qq.com SKYPE: Live broadcast: 378632242
2:2SK182ES K182ES NOS NEW v-fet TOKIN from Japan Spot quantity: 50PCS
Matching price: USD: 100/1PCS Thf-51s 2SK182ES features: each has a different sequence number, a different number, a 1-10 number (this is a brand new original, only owned by NOS)
Mica thickness 4.5 (thickest)
Buy thf-51s 2SK182ES for free insulating pads, mica sheets, screws
It can be delivered in a package
(if you do not have a friend who bought thf-51s, you need to pay the postage by yourself. If you need, you can leave a message or send it to my email:378632242@qq.com.)
See the picture:
MJ21193G MJ21194G MJ21194 MJ21193 NOS NEW ON Motorola
1pair=USD:11.56
QTY:80pair
NOS NEW ON MJ21193G MJ21194G MJ21193 MJ21194 250V-16A-200W-4MHZ
LM350K LM350K STEEL
USD:11.57 /1PCS
NEW NOS LM350K LM350K STEEP+ 9712+ I have 50PCS
NSC 8608+ LM350K STEEP+ I have 620PCS
LM350K STEEL NEW NOS NSC TO-3 NEW STEELP+ 0142+ NOS 1PCS USD:11.57 I have 785PCS
Brand NSC
Model LM350k
MAX input voltage 35V
The input voltage of MINIi is 4.2V
Adjust the voltage 1.2-33v direct current
Current 3 a MAX
To encapsulate the to - 3
With the original packaging, packaging foam board is die-cast with the manufacturer's brand. I take it apart. I take it apart. Here is a picture of the tube wafer taken by someone using an electron microscope. It can be seen that the wafer is made in Britain. He who knows is sure to know the goods.
The national semiconductor company makes LM350k. It's not a big problem to play with equipment. The money you really spend is worth it. It is also clear that the foam packaging of this tube is also special and each is individually attached to the tube, rather than the usual one with a cylinder in the middle to separate the surrounding tube. It can directly replace the LM317. This tube can be regarded as the more powerful LM317. The current is twice that of 317, reaching 3A. It is a good choice to supply the machine with sufficient current. Naim power supply board made of high current pipe with low internal resistance, which is a feature pursued by burning friend. Spread knowledge by the way. The quality of the steel tube on the net varies greatly, there are used polish to fill the new, some of the pin resin seal holes are large holes. This kind of imported tubes are all small holes. The color of resin is mainly black, brown, green and red, with few blue. The printed word on the surface of the normal pipe is in the middle, and the position is basically the same. Word is not raised, a bit of brown black, and the surface coating is matte color, won't be very bright, that is polished. Iron tube screw fixation will leave a mark on the screw hole where can distinguish between used and new. This tube is typically quoted at more than 300, which is more expensive than LT's 317.
Refer to the official PDF map for details. You can download the PDF for reference.
Shipping and ordering T&C
Sort:
Please give me a PM with the following information:
Forum ID:
Real name:
The recipient:
Contact number:
Mailing address:
Paypal account email:
Bill of materials, quantity and options
The value of the parcel declared for customs/insurance purposes.
payment:
Exclusively provided by PayPal. PayPal fees are always included in the displayed price.
Prices are shown in US dollars, please specify when placing an order.
Shipping and handling:
Shipping fee and courier method: China Post 12day-20day
After receiving PayPal, I will ship within 2 business days.
If someone has not received your package within 20 business days of my delivery notice, please let me know.
The shipping and packaging charges for the order are: 1PCS-4PCS=USD: 12.0 In some countries, China post freight only needs USD: 10.0 (Some countries have far-fetched fare, shipping rates may be high+: USD: 2.0)
4PCS-8PCS=USD: 15.0 (some countries are far away, shipping costs may be high+ USD: 2.0)
Buyers in mainland China, Hong Kong and Taiwan can support the payment (support SF Express)
DHL：If the buyer is in a hurry and wants to receive the goods soon, you can choose DHL.
Shipping fee is: 1PCS-4PCS=USD: 29.22
5PCS-10PCS=USD: 43.84
Because the contract with DHL Express, so the freight, gave me the advantage of the price, the freight will be cheaper
The time limit is: 4-5 days to receive
运输政策：请注意，包裹保险不包含在运输条款和条件中指定的运输费用中。请联系我获取保险报价。如果您想为包裹购买保险，请考虑使用更可靠的递送服务提供商，例如 DHL、EMS 或 FEDEX。 PM，给我留言，如果接受条件，请只下订单。谢谢您的理解。
2SK182ES thf-51s 需要一个匹配的朋友
请留言
Pairing就是配对的价格（PM就可以了）
当我不忙的时候，我会测量。下面是2SK182ES的流程。
For sale CMF10120 CMF10120D SJEP120R100 SJEP120R125 SJEP120R063 SJDP120R085....
- By pras1170
- Vendor's Bazaar
- 19 Replies
now have NEW
SJEP120R125 30pcs
SJEP120R063 34PCS
SEJP120R063C2 5PCS
SJDP120R085 15pcs
SJEP120R125 30pcs
SJEP120R063 34PCS
SEJP120R063C2 5PCS
SJDP120R085 15pcs
-
Locked
What are the Capacitors ??
- By thebear13
- Analog Line Level
- 1 Replies
Hi - noobie post. I was looking to upgrade these old capacitors in my tube pre-amp. I am not sure what the these values are - one of them says ' 100M + 100M , and the other 2 say ' 32M + 32M ' - any ideas , guys ???
