PS Audio Stellar Gain Cell issues with one channel DC output, help
- By ants2au
- Solid State
- 1 Replies
Attachments
Audio Board - Asus - REW
- By jeffrowland
- Equipment & Tools
- 5 Replies
I ran some tests with REW while waiting for the Scarlet 2i2 3rd.
On the Asus motherboard there is a 5.1 that I use in 2.1 (4front/modified) and on the subwoofer there is a 5" Vifa.
Here is the measurement of the card with this configuration.
How do you think?
On the Asus motherboard there is a 5.1 that I use in 2.1 (4front/modified) and on the subwoofer there is a 5" Vifa.
Here is the measurement of the card with this configuration.
How do you think?
Remove tweeter from cabinet
- Construction Tips
- 14 Replies
Would anyone be able to provide some suggestions for removing a tweeter from a cabinet. I don’t have any experience fixing speakers, but thought I tried. I have an old Fischer and Fischer 1000 built in 2000 that I am restoring. I’m trying to remove a damaged tweeter. The outer plate seems glued-in, but why would someone do that? The bass drivers are not glued-in and were removed easily. I don’t want to exert too much force as to not damage the aluminum plate. Things I tried:
1. I used a heat gun to loosen any glue, but I don’t think I got it hot enough I was afraid of using too much heat.
2. Prying/pulling: I exerted more force than I thought should be necessary, but I stopped due to fear of damaging the outer plate.
Any thoughts would be appreciated.
1. I used a heat gun to loosen any glue, but I don’t think I got it hot enough I was afraid of using too much heat.
2. Prying/pulling: I exerted more force than I thought should be necessary, but I stopped due to fear of damaging the outer plate.
Any thoughts would be appreciated.
opinions
- By bikerjay
- Electronic Design
- 5 Replies
I got my speakers built today. I just need to figure out the crossovers. I'm attempting a 2.5 way (as I understand it) since it is a MTM. I'm still not 100% on any of it really but what phase should look like on a graph is what I'm least sure of. Phase is represented by the thin line. I'm confident that its not perfect but it's not bad either
Attachments
Amplifier with Predictable Output Impedance
- By Jontie
- Solid State
- 14 Replies
I'd like to present a design for a power amplifier, the main features of which are as follows:
The principle on which the design is based is that of a current (high-impedance) amplifier, using feedback to reduce the output impedance.
Full details, including a practical design example, can be found at: https://robinet.co.uk/amplifier-design.
I have attached RTA spectra plots taken using REW, showing the performance of this design at 1 Watt into 8 Ohms, and at 100 Watts into 4 Ohms.
Comments will be welcome.
- The output impedance can be varied from a fraction of an Ohm, to several Kilo-ohms, by selecting two resistors.
- The amplifier is stable with virtually any load.
- It is very robust, and can survive accidental short-circuits.
- Total harmonic distortion is below 0.02% at 1 watt into 8 Ohms, up to 40kHz (This is a real measurement, not a simulation).
The principle on which the design is based is that of a current (high-impedance) amplifier, using feedback to reduce the output impedance.
Full details, including a practical design example, can be found at: https://robinet.co.uk/amplifier-design.
I have attached RTA spectra plots taken using REW, showing the performance of this design at 1 Watt into 8 Ohms, and at 100 Watts into 4 Ohms.
Comments will be welcome.
Hello from Saudi Arabia!
- By jareif
- Introductions
- 1 Replies
I have been scouring these forums for the past few months as my sons and I have embarked on a loudspeaker design project (two projects concurrently, actually). We have finally run into a roadblock which I don't know how to resolve and have concluded it is time to join the forum officially and seek some help!
We are an American family residing in Riyadh, Saudi Arabia.
Here are simple blender images of my two sons' designs:
We are an American family residing in Riyadh, Saudi Arabia.
Here are simple blender images of my two sons' designs:
How to fix these?
I have this speaker that stopped working and put my Yamaha into protect mode . I took it apart once but couldn’t find a x over or anything??? It seems a cord got loose and i attached it to the wrong spot .
Attachments
NE5532 is a popular opamp
- By lineup
- Analog Line Level
- 104 Replies
Look at these two circuits. They do the same.
The difference is the single and the dual supply.
Another difference is the capacitor C1 and C3.
Because the negative voltage at input pin C3 should be put 'upside down'.
This goes for all bipolar opamps with NPN input transistors.
And when using dual voltage supply.
If a bipolar opamp has PNP transistors input the C3 should be turned the other way.
Iron Pumpkin(s) and other smaller vegetable animals, Tips 'n' Tricks thread
Well, origin thread is here : Iron Pumpkin(s) and other smaller vegetable animals
If nothing else, read at least first several posts on linked page , to grasp enough info about concept itself.
This one having two purposes :
-placing all necessary info about final iteration,
-trying to layout clearer picture of what's fuss about,
-with edits of this first post - making comprehensive list of tips and tricks and funny fine details , and answering on any clever or dumb question you'll possibly have ......either here or further in thread
(3 purposes then , not two
)
edit at 22.05.2020. short how-to-do for Iron Pumpkin SE, referencing to post #2:
do not connect buffer output to Turtle
maximize trimpot R36 (measure across R39 to confirm max value)
R37 position is irrelevant for now
if you're sure that you connected everything properly, just power it on
set positive and negative rails to +/-12Vdc , with trimpots R9 and R10
power off, place DVMdc crocs across R34, power On then fiddle with R36 to set 20mV across R34, then fiddle with R37 to set 0mV DC offset at output
do everything the same with other channel, connect outputs of buffers to Turtle, enjoy
If nothing else, read at least first several posts on linked page , to grasp enough info about concept itself.
This one having two purposes :
-placing all necessary info about final iteration,
-trying to layout clearer picture of what's fuss about,
-with edits of this first post - making comprehensive list of tips and tricks and funny fine details , and answering on any clever or dumb question you'll possibly have ......either here or further in thread
(3 purposes then , not two
)edit at 22.05.2020. short how-to-do for Iron Pumpkin SE, referencing to post #2:
do not connect buffer output to Turtle
maximize trimpot R36 (measure across R39 to confirm max value)
R37 position is irrelevant for now
if you're sure that you connected everything properly, just power it on
set positive and negative rails to +/-12Vdc , with trimpots R9 and R10
power off, place DVMdc crocs across R34, power On then fiddle with R36 to set 20mV across R34, then fiddle with R37 to set 0mV DC offset at output
do everything the same with other channel, connect outputs of buffers to Turtle, enjoy
Baby's first sub-filter
- By njswede
- Subwoofers
- 2 Replies
I found myself with time on my hands and enough parts to build a subwoofer and a plate amp (based on The Bog Standard) so I figured "why not?". I also needed a filter, so I drew one up. It's probably pretty naive. Just a simple preamp/buffer and a second order Sallen Key filter. I want to be able to set the cutoff frequency, so I made one of the resistors in the Sallen Key-filter variable. This works in SPICE as well as on breadboard. But is this too naive? I'm also getting about 50-60 degrees phase shift at the cutoff frequency. Should I be worried about this? Ideas for improvement are appreciated!
Tokin DEFISIT Duo Capacitor Output Stage Amplifier
Here is my latest Tokin SIT amplifier. It is a DEFISIT amp (Depletion Enhancement Follower SIT) output stage based on Nelson's First Watt SIT-5 output stage. Diyers more knowledgeable than me picked apart what information Nelson provided in his SIT-5 owners' manual (https://www.diyaudio.com/community/threads/first-watt-sit5.418023/), and I rode on their coattails and came up with this version.
My build is only the output stage, and it incorporates the duo output capacitor arrangement which can be tweaked to adjust the amount of current amplification that the mosfet part of the DEFISIT push-pull output contributes to the total current amplification. This is a departure from the regular DEFISIT amplifier, where the SIT and mosfet both fully contribute to the total current amplification.
Here are a couple of LTSpice simulations. I did many simulations, but these two are what I based my design on. I chose -47VDC for one sim since I intended to build it using one of my existing amplifier chassis and power supply. I chose the -63VDC for the other since that is a reasonable voltage that will take advantage of the power capability of the THF-51S and still keep the power supply voltage reasonable for capacitor voltage and heat sink heat dissipation.
As shown in the simulation results (47VDC power supply and 2.0A Iq), the measured current through C4 connected to the SIT drain was 361mA peak, the measured current through C7 connected to the mosfet drain was 150mA, for a total of 511mA. As a check the current measured through the speaker, R8, was 509mA - close enough. So the contribution of the mosfet was 150mA/511mA = 29%.
I have not included the LTSpice screen shots of power output but the 8 Ohm power output was nearly 23W at 1% THD and 4 Ohm power output was nearly 40W at 1% THD.
63VDC PS 2A 8R 1Watt:
63VDC PS 2A AC signal current through C4, C7, and 8R Speaker:
47VDC PS 2A 8R 1Watt:
47VDC PS 2A AC signal current through C4, C7, and 8R Speaker:
As mentioned I decided to build the 47VDC version. The chassis and power supply is from my BAF2015 Amplifier - A SIT Mu Follower Revisited With Feedback (https://www.diyaudio.com/community/...t-mu-follower-revisited-with-feedback.408193/). The power supply is CLC, comprising 2x22mF - Hammond 156B - 2x22mF, and an Antek AS-3218 transformer per channel for full dual mono construction.
I put together a PCB design and sent it off to JLCPCB for fabrication. In addition to stuffing the PCB once I received it, I also changed the CLC filter from V+ supply to V- supply.
Initial power-up and subsequent Iq and SIT Vds adjustments went smoothly, and Iq and SIT Vds were stable.
Next up was testing with an 1kHz signal and distortion measurements. Unfortunately when powered up with an AC line powered 1kHz oscillator connected, the amp immediately blew the powerline fuse. So it was trouble shooting time. After checking the schematic and pcb, checking that the input capacitor was not faulty, and not finding any visible ground shorts with the meter, I was baffled.
I knew that the issue was mostly likely a grounding problem and that it only manifested itelf when an input device was connected to the amplifier. Luckily a thought came to me fairly quickly - when I changed the CLC filter from V+ to V- supply, I forgot to move the power supply connection to safety ground on the CLC filter board. The correction was made and success. Only one fuse was permanently damaged.
The dim bulb tester came in handy here as once the fuse blew, the dim bulb tester went in and I was able to probe around with power and not blow anything. In addition to using it during trouble shooting, I always use it for first power-up testing of power supplies during various stages of construction and first power-up testing of audio circuits.
As for the amplifier supply not shorting with no input device connected but shorting with an input device connected, I gave it some thought. The power supply was for V-, with V- from the supply connected as power to the amplifier circuit. V+ from the supply was connected to the amplifier circuit board as ground. The V- from the supply was ground in the previous amplifier but I forgot to change it so it was now incorrectly connected to chassis safety ground. With no input device connected to the amplifier circuit, the power to the amplifier board was floating. Although the V- was also connected to the chassis safety ground and to the powerline/IEC ground, there was no other direct connection to V+, so no short. The live from the powerline/IEC was connected to the transformer primary, which was isolated from the transformer secondary. Also the speaker and input jacks were isolated from the chassis. So with no complete direct connection of V- to V+, the current can only flow through the audio circuit. The chassis was connected to V- but there was no path for the current to flow from the chassis to power supply V+.
When the oscillator was connected to the amplifier input, the circuit was completed, current flowed, and the fuse blew. That was because the oscillator was AC powered and had a safety ground connection. So the oscillator line safety ground connected to the oscillator power supply ground, then connected to the oscillator signal ground, then connected to the amplifier signal ground, then connected to the amplifier V+. The oscillator safety ground is also connected to the amplifier safety ground through the line ground, and the amplifier safety ground is connected to amplifier V-. The net result was amplifier V+ and amplifier V- were connected together - a short circuit. There was a CL60 thermistor at the amplifier power supply ground connection. That would have limited the short circuit current: 47V/10R = 4.7A. Fuse was 2.5A slow blow.
I have swapped power supply polarity before but had always remembered to switch the safety ground connected, until this time.
So always be careful. Electricity can kill.
My build is only the output stage, and it incorporates the duo output capacitor arrangement which can be tweaked to adjust the amount of current amplification that the mosfet part of the DEFISIT push-pull output contributes to the total current amplification. This is a departure from the regular DEFISIT amplifier, where the SIT and mosfet both fully contribute to the total current amplification.
Here are a couple of LTSpice simulations. I did many simulations, but these two are what I based my design on. I chose -47VDC for one sim since I intended to build it using one of my existing amplifier chassis and power supply. I chose the -63VDC for the other since that is a reasonable voltage that will take advantage of the power capability of the THF-51S and still keep the power supply voltage reasonable for capacitor voltage and heat sink heat dissipation.
As shown in the simulation results (47VDC power supply and 2.0A Iq), the measured current through C4 connected to the SIT drain was 361mA peak, the measured current through C7 connected to the mosfet drain was 150mA, for a total of 511mA. As a check the current measured through the speaker, R8, was 509mA - close enough. So the contribution of the mosfet was 150mA/511mA = 29%.
I have not included the LTSpice screen shots of power output but the 8 Ohm power output was nearly 23W at 1% THD and 4 Ohm power output was nearly 40W at 1% THD.
63VDC PS 2A 8R 1Watt:
63VDC PS 2A AC signal current through C4, C7, and 8R Speaker:
47VDC PS 2A 8R 1Watt:
47VDC PS 2A AC signal current through C4, C7, and 8R Speaker:
As mentioned I decided to build the 47VDC version. The chassis and power supply is from my BAF2015 Amplifier - A SIT Mu Follower Revisited With Feedback (https://www.diyaudio.com/community/...t-mu-follower-revisited-with-feedback.408193/). The power supply is CLC, comprising 2x22mF - Hammond 156B - 2x22mF, and an Antek AS-3218 transformer per channel for full dual mono construction.
I put together a PCB design and sent it off to JLCPCB for fabrication. In addition to stuffing the PCB once I received it, I also changed the CLC filter from V+ supply to V- supply.
Initial power-up and subsequent Iq and SIT Vds adjustments went smoothly, and Iq and SIT Vds were stable.
Next up was testing with an 1kHz signal and distortion measurements. Unfortunately when powered up with an AC line powered 1kHz oscillator connected, the amp immediately blew the powerline fuse. So it was trouble shooting time. After checking the schematic and pcb, checking that the input capacitor was not faulty, and not finding any visible ground shorts with the meter, I was baffled.
I knew that the issue was mostly likely a grounding problem and that it only manifested itelf when an input device was connected to the amplifier. Luckily a thought came to me fairly quickly - when I changed the CLC filter from V+ to V- supply, I forgot to move the power supply connection to safety ground on the CLC filter board. The correction was made and success. Only one fuse was permanently damaged.
The dim bulb tester came in handy here as once the fuse blew, the dim bulb tester went in and I was able to probe around with power and not blow anything. In addition to using it during trouble shooting, I always use it for first power-up testing of power supplies during various stages of construction and first power-up testing of audio circuits.
As for the amplifier supply not shorting with no input device connected but shorting with an input device connected, I gave it some thought. The power supply was for V-, with V- from the supply connected as power to the amplifier circuit. V+ from the supply was connected to the amplifier circuit board as ground. The V- from the supply was ground in the previous amplifier but I forgot to change it so it was now incorrectly connected to chassis safety ground. With no input device connected to the amplifier circuit, the power to the amplifier board was floating. Although the V- was also connected to the chassis safety ground and to the powerline/IEC ground, there was no other direct connection to V+, so no short. The live from the powerline/IEC was connected to the transformer primary, which was isolated from the transformer secondary. Also the speaker and input jacks were isolated from the chassis. So with no complete direct connection of V- to V+, the current can only flow through the audio circuit. The chassis was connected to V- but there was no path for the current to flow from the chassis to power supply V+.
When the oscillator was connected to the amplifier input, the circuit was completed, current flowed, and the fuse blew. That was because the oscillator was AC powered and had a safety ground connection. So the oscillator line safety ground connected to the oscillator power supply ground, then connected to the oscillator signal ground, then connected to the amplifier signal ground, then connected to the amplifier V+. The oscillator safety ground is also connected to the amplifier safety ground through the line ground, and the amplifier safety ground is connected to amplifier V-. The net result was amplifier V+ and amplifier V- were connected together - a short circuit. There was a CL60 thermistor at the amplifier power supply ground connection. That would have limited the short circuit current: 47V/10R = 4.7A. Fuse was 2.5A slow blow.
I have swapped power supply polarity before but had always remembered to switch the safety ground connected, until this time.
So always be careful. Electricity can kill.
symphonic-mpd
- By papalius
- Vendor's Bazaar
- 417 Replies
The content of this thread is my personal opinion and does not represent performance based on objective metrics.
Information about symphonic-mpd, a CRAFTED LINUX for Raspberry Pi4.
It has been developed to target audiophile who want high quality music playback on I2S output.
Official Forum
symphonic-mpd
If you are interested, please ask your questions in this thread.
In order to use the SD images of this distribution, you need to join the official forum.
If you would like to join, please email me below with your handle name.
symphonic.mpd@gmail.com
kubotayo@jcom.home.ne.jp
mark.create@gmail.com
Information about symphonic-mpd, a CRAFTED LINUX for Raspberry Pi4.
It has been developed to target audiophile who want high quality music playback on I2S output.
Official Forum
symphonic-mpd
If you are interested, please ask your questions in this thread.
If you would like to join, please email me below with your handle name.
symphonic.mpd@gmail.com
kubotayo@jcom.home.ne.jp
mark.create@gmail.com
Troels Gravesen AtiRi
- By noamgeller
- Multi-Way
- 22 Replies
So, the kit of the AtiRi has been bought and I am thinking of pumping it up and make a Kawero Classic clone (kind of) out of it.
But I need your help regarding the bass segment.
My plan is simple, take the two way AtiRi (15Liter) and put on a 40Liter bass reflex cabinet. untill now same as Kawero.
The woofer I will use for the 40Liter is the 10inch Faitalpro RS350. it will be driven by Hypex Fa501.
Now, I really really want to nail this bass, clean accurate, powerful.
So the following ideas are:
1. 40liter-bass reflex with one RS350 10inch driver
2. 40liter- closed cabinet with one RS350 10 inch driver -infinite baffle
3. 40liter- Closed cabinet with Two!! RS350 10 inch driver
I know its more about opinions and everything is a compromise but it would be great to hear your preferences.
Thanks!
But I need your help regarding the bass segment.
My plan is simple, take the two way AtiRi (15Liter) and put on a 40Liter bass reflex cabinet. untill now same as Kawero.
The woofer I will use for the 40Liter is the 10inch Faitalpro RS350. it will be driven by Hypex Fa501.
Now, I really really want to nail this bass, clean accurate, powerful.
So the following ideas are:
1. 40liter-bass reflex with one RS350 10inch driver
2. 40liter- closed cabinet with one RS350 10 inch driver -infinite baffle
3. 40liter- Closed cabinet with Two!! RS350 10 inch driver
I know its more about opinions and everything is a compromise but it would be great to hear your preferences.
Thanks!
3-way - port tube placement and braces
Hi all
I'm trying to design a 3-way speaker based on mid-range and tweeter I already have (used in a 2 way speaker some years ago).
I decided to add SB26SFCL38-8 to these 2 drivers in bass reflex configuration. The volume for the woofer will be around 88L with a resonant frequency is 27Hz.
I want create a cabinet with hard plywood 19mm with external size WxDxH 38x55x63 (the height is a constraint).
The cabinet will have a "small room" for the mid and tweeter of about 8L.
The port tube will have diameter of 9,2 cm and length of 22,5 cm
I have 2 main doubts now (may be more 🙂)
1. Where put the port tube. I have not enough space below the woofer do I would like to place it upper. Something like this...
I also did a try with 2 port of 6,6 cm and 24,5 cm length below the woofer.
What do you think is the best solution?
2. How many braces, where to place them and how shape them. I'm not so expert about this aspect.
I'm trying to design a 3-way speaker based on mid-range and tweeter I already have (used in a 2 way speaker some years ago).
I decided to add SB26SFCL38-8 to these 2 drivers in bass reflex configuration. The volume for the woofer will be around 88L with a resonant frequency is 27Hz.
I want create a cabinet with hard plywood 19mm with external size WxDxH 38x55x63 (the height is a constraint).
The cabinet will have a "small room" for the mid and tweeter of about 8L.
The port tube will have diameter of 9,2 cm and length of 22,5 cm
I have 2 main doubts now (may be more 🙂)
1. Where put the port tube. I have not enough space below the woofer do I would like to place it upper. Something like this...
I also did a try with 2 port of 6,6 cm and 24,5 cm length below the woofer.
What do you think is the best solution?
2. How many braces, where to place them and how shape them. I'm not so expert about this aspect.
For Sale ATC SB76-314SC
For sale a pair of ATC SB75-314S in very good condition and with fresh new surrounds.
They can be used as well to replace the SB75-314SL because they behave and measure equal to those. Just Some better an more linear roll off in the SL. The SL has not a resonance peak more than 12dB below crossover point at 500/600Hz.
Price for the pair will be 450€ + PP fees + Shipping at cost.
They can be used as well to replace the SB75-314SL because they behave and measure equal to those. Just Some better an more linear roll off in the SL. The SL has not a resonance peak more than 12dB below crossover point at 500/600Hz.
Price for the pair will be 450€ + PP fees + Shipping at cost.
NSM4202A LED Display Module Replacement for Philips / Sony CDM Transports
- By NoNameXII
- Digital Source
- 16 Replies
I have an old Krell MD-2 CD turntable, and (among other issues) several segments have gone out on the LED display. After looking around online, I found one person in France that had built a replacement, but details were kind of scarce, so tried to reverse engineer my display module based upon the tidbits of information that I was able to uncover.
After hooking it up to a scope, it appeared to use SPI (keep in mind that I'm not very smart), but I just got rubbish when I created a small Arduino program to read the data, so I traipsed through the available LED drivers on DigiKey, and came across the MM5450 as one of the very few chips that didn't require I2C. Upon reviewing the data stream again, it appeared to fit with what was required to drive this chip. Anyway, I did the best that I could to guess the pinout of my existing display board (it uses an unmarked glob to hold down the IC die), and was able to reconcile it with the MM5450 pinout, so I made up a board, bought some parts, and tried it out. It appears to be fully functional, so I thought that I would share it here so that others can create a replacement for themselves as necessary. I'm kind of hoping that since this hardware is over 25 years old (and apparently out of production for quite some time) that Philips won't mind too much the publishing of plans for a replacement...
Anyway, here goes with the information:
Feel free to use this information however you wish, so long as you don't make anyone pay for it. I don't care if you charge someone to assemble a board for them or something (it's none of my business), but the information should be kept in the open. I abhor GPL-like licensing, but I do expect you to not be a turd.
I am just a hobbyist (and a really unintelligent one at that), so I do not make any representation that information is accurate, safe, or suitable for any purpose, even a purpose that may be implied by the information. In other words, I did the best that I could, it worked for me, but it's not on me if you hurt yourself or start a fire or something.
I have the board shared at OSH Park (https://oshpark.com/shared_projects/P3nC9ISV) for convenience. I make nothing from this link or design (AFIAK), and I don't care from where you order your board.
BOM:
Electrical Schematic:
View attachment NSM4202A Schematic.pdf
Front of PCB:
Back of PCB:
Gerbers for PCB:
View attachment NSM4202A.zip
DipTrace Schematic and Board Files:
View attachment NSM4202A DipTrace Files.zip
After hooking it up to a scope, it appeared to use SPI (keep in mind that I'm not very smart), but I just got rubbish when I created a small Arduino program to read the data, so I traipsed through the available LED drivers on DigiKey, and came across the MM5450 as one of the very few chips that didn't require I2C. Upon reviewing the data stream again, it appeared to fit with what was required to drive this chip. Anyway, I did the best that I could to guess the pinout of my existing display board (it uses an unmarked glob to hold down the IC die), and was able to reconcile it with the MM5450 pinout, so I made up a board, bought some parts, and tried it out. It appears to be fully functional, so I thought that I would share it here so that others can create a replacement for themselves as necessary. I'm kind of hoping that since this hardware is over 25 years old (and apparently out of production for quite some time) that Philips won't mind too much the publishing of plans for a replacement...
Anyway, here goes with the information:
Feel free to use this information however you wish, so long as you don't make anyone pay for it. I don't care if you charge someone to assemble a board for them or something (it's none of my business), but the information should be kept in the open. I abhor GPL-like licensing, but I do expect you to not be a turd.
I am just a hobbyist (and a really unintelligent one at that), so I do not make any representation that information is accurate, safe, or suitable for any purpose, even a purpose that may be implied by the information. In other words, I did the best that I could, it worked for me, but it's not on me if you hurt yourself or start a fire or something.
I have the board shared at OSH Park (https://oshpark.com/shared_projects/P3nC9ISV) for convenience. I make nothing from this link or design (AFIAK), and I don't care from where you order your board.
BOM:
- U1 - Micrel MM5450 (PLCC-44) LED Display Driver
- DS1-DS4 - Kingbright ACSA03-41SGWA-F01 7-Segment Common-Anode LED Display (Green, other colors probably available)
- D1-D2 - 0603 SMD LED (Green for use with the specified green LED digits)
- R1 - 7.5kOhm (or higher) 1206 SMD Resistor (controls brightness)
- C1 - 1000pF 1206 SMD Capacitor
- J1-J3 - 0.1" header system of your choice
Electrical Schematic:
View attachment NSM4202A Schematic.pdf
Front of PCB:
Back of PCB:
Gerbers for PCB:
View attachment NSM4202A.zip
DipTrace Schematic and Board Files:
View attachment NSM4202A DipTrace Files.zip
Why would an amp designer intentionally use different OPT impedances for Left vs. Right?
- By wparks
- Tubes / Valves
- 22 Replies
(I posted this on the AK forum, and so far nobody can give me a good answer, so a gold star to the one who can . . .)
So I'm thinking for my next tube amp build I would really like to do a little integrated 6AQ5 push-pull, so I was researching some of the greats, and apparently the Voice of Music 1404 integrated amplifier (581 console) really stands out as a super performer based upon many comments I have read.
I have a one page schematic, as well as a pdf copy of the SAMs posted below for the model 581 console, which used essentially the same chassis. It very clearly shows that the left and right output transformers are different- one has a primary impedance of 5700 ohms, the other is 7000 ohms. This is confirmed in the schematic, which indicates a different DCR for each primary (325 vs 340 ohms per side). These are not two "alternates" or an accident, this is a deliberate design choice to use a different load line (but same operating point) for left versus right.
Does anyone know why this would be done? I have never seen that before.
BTW I think the super cheap 6AQ5 (essentially a 6V6 in a 7-pin peanut) will be very fun to play with- guitar amps are using them like crazy but still seem to be quite overlooked in new audio builds.
So I'm thinking for my next tube amp build I would really like to do a little integrated 6AQ5 push-pull, so I was researching some of the greats, and apparently the Voice of Music 1404 integrated amplifier (581 console) really stands out as a super performer based upon many comments I have read.
I have a one page schematic, as well as a pdf copy of the SAMs posted below for the model 581 console, which used essentially the same chassis. It very clearly shows that the left and right output transformers are different- one has a primary impedance of 5700 ohms, the other is 7000 ohms. This is confirmed in the schematic, which indicates a different DCR for each primary (325 vs 340 ohms per side). These are not two "alternates" or an accident, this is a deliberate design choice to use a different load line (but same operating point) for left versus right.
Does anyone know why this would be done? I have never seen that before.
BTW I think the super cheap 6AQ5 (essentially a 6V6 in a 7-pin peanut) will be very fun to play with- guitar amps are using them like crazy but still seem to be quite overlooked in new audio builds.
Attachments
Apollo Light Drive
- By gerrittube
- Power Supplies
- 4 Replies
Light fantastic
“The P1 power amplifier requires a super clean high current power supply to turn the low voltage line level music signal into hundreds of watts of output power. To do this, Siltech designed the Apollo Light Drive. A super-strong AC-powered light source is used to drive a photo-electric cell, giving a totally noise-free, galvanically isolated DC output. This then drives the amplifier’s output stage, keeping it absolutely immune from mains-born distortion. The idea behind this is not new, but its execution in a high powered amplifier is extremely challenging. The result is ultra-clean, low distortion power – and lots of it.”
Has anyone tried DIYing this concept?
https://www.siltechcables.com/saga-amplifier-system/
Luxman L-3 project - High voltage at speaker terminals
- By Phelicks
- Solid State
- 10 Replies
Attachments
AULA02014 8" + Celestion CDX1 CD with Harsch XO sorta
- By AdamThorne
- Multi-Way
- 16 Replies
I bought these drivers back in end August I think it was, and I've finally got a box for 'em. I've measured up the in box response and played around with the results in XSIM. I still have to order XO parts, and do a final sand and finish on the boxes. But I thought I'd share where I'm at.
I kicked out a thread to discuss the drivers when I ordered them, it's https://www.diyaudio.com/community/threads/tymphany-aula02014-0006-pe-buyout.416365/
Woofer (buyout, NLA) is this 8" tymphany pro audio with a big honker magnet
https://www.parts-express.com/Tymph...-Paper-Cone-Woofer-8-Ohms-299-2265?quantity=1
I got 'em for $17 each!
Compression driver is Celestion CDX1-1446
https://www.parts-express.com/Celes...-Compression-Driver-8-Ohm-299-2257?quantity=1
This one is also a buyout but I think the same driver is available regular production.
I've got it on this JBL Selenium HM17-25 https://www.parts-express.com/Selen...al-Horn-60x40-1-3-8-18-TPI-264-308?quantity=1
I have modeled it up in 30 L and ported at 60 Hz. Software wanted to suggest smaller / higher, but I'm trying to get this thing to dig down far enough to cross to my sub. I have 3D printed a port according to geometry in this Harmon paper about optimizing ports. https://www.diyaudio.com/community/attachments/harman-port-study-pdf.893225/
I was trying to conceptualize how I'd put this speaker together, and I thought of trying to time-align the drivers, so I measured the acoustic offsets. The horn+tweeter came out 70mm behind the driver (mounting features in the same plane), which was more than I was expecting. I had a little thread to consider options about that https://www.diyaudio.com/community/...nique-for-horn-out-front.419357/#post-7851615 eventually I remembered that @xrk971 has a crossover topology that wants the tweeter a fair bit delayed WRT the woofer, and that's the Harsch XO, he's got a thread about it here - https://www.diyaudio.com/community/threads/s-harsch-xo.277691/. I was considering a 2kHz XO, and the delay according to the Harsch thing was 85mm, so another sheet of plywood for the woofer to sit on was just about right.
So that's about how I dreamed this one up! Here's how it looks...
Ah... every thread is better with pictures. I've got roundover I think it's 1" on the vertical corners. Boxes made of arauco ply 3/4" from Home Depot, I'm still trying to decide how I'm gonna finish them. I like the lines from the ply on front.
Ground plane, on-axis (spkr tilted down to point at the mic) 2m distance acoustic measurements look like this
THD is good on the woofer, and FR is fine to 3k, but I think that is a low baffle step from 100 to 500? Speaker is 12.5" wide. Anyway that shift ended up being around the upper of the two impedance peaks in low woofer response, that made it kinda tricky to correct passively. FR on the tweeter seems pretty nice, but measurement looks like kinda high 2nd order HD.
I've been fiddling with the XO sim to get something I like.... here's where I'm at.
Initial idea was to have the cross at 2k, but in the course if trying to make it work I have floated up from there. So I think my offset is actually a little too much, and my phase peak is a bit larger than it might have been.
If you go for this sort of XO, it is (quoted from XRK's thread)...
1. Set the low pass filter for the woofer as a 4th order Butterworth at central frequency, fc for the XO centerpoint.
2. Set the high pass filter for the tweeter as a 2nd order Bessel at fc.
3. Set the delay of the tweeter equal to 1/2 of the period of one cycle at fc.
4. Use all positive phase on woofer and tweeter.
Here's what I've learned: 2nd order -acoustic- roll off is pretty slow! 2nd order electrical is normally fine, but when you are looking at the acoustic rolloff that happens naturally that doesn't leave much space to put in electrical protection. So I ended up at higher F than I was initially targeting. It looks like 2nd order electrical on the CD but it's pretty low Q, that inductor is only helping out at lower frequencies. Impedance compensation on the CD can help you get the shape theory wants.
I think I've attached the XSIM file in case anyone wants to play along.
I'm looking forward to hearing these, but I haven't pulled the trigger on XO parts yet. Every time I buy parts a couple days later I'm like "you know what I SHOULDA done...?" so I'm still meditating on it.
What do you think?
- Adam
I kicked out a thread to discuss the drivers when I ordered them, it's https://www.diyaudio.com/community/threads/tymphany-aula02014-0006-pe-buyout.416365/
Woofer (buyout, NLA) is this 8" tymphany pro audio with a big honker magnet
https://www.parts-express.com/Tymph...-Paper-Cone-Woofer-8-Ohms-299-2265?quantity=1
I got 'em for $17 each!
Compression driver is Celestion CDX1-1446
https://www.parts-express.com/Celes...-Compression-Driver-8-Ohm-299-2257?quantity=1
This one is also a buyout but I think the same driver is available regular production.
I've got it on this JBL Selenium HM17-25 https://www.parts-express.com/Selen...al-Horn-60x40-1-3-8-18-TPI-264-308?quantity=1
I have modeled it up in 30 L and ported at 60 Hz. Software wanted to suggest smaller / higher, but I'm trying to get this thing to dig down far enough to cross to my sub. I have 3D printed a port according to geometry in this Harmon paper about optimizing ports. https://www.diyaudio.com/community/attachments/harman-port-study-pdf.893225/
I was trying to conceptualize how I'd put this speaker together, and I thought of trying to time-align the drivers, so I measured the acoustic offsets. The horn+tweeter came out 70mm behind the driver (mounting features in the same plane), which was more than I was expecting. I had a little thread to consider options about that https://www.diyaudio.com/community/...nique-for-horn-out-front.419357/#post-7851615 eventually I remembered that @xrk971 has a crossover topology that wants the tweeter a fair bit delayed WRT the woofer, and that's the Harsch XO, he's got a thread about it here - https://www.diyaudio.com/community/threads/s-harsch-xo.277691/. I was considering a 2kHz XO, and the delay according to the Harsch thing was 85mm, so another sheet of plywood for the woofer to sit on was just about right.
So that's about how I dreamed this one up! Here's how it looks...
Ah... every thread is better with pictures. I've got roundover I think it's 1" on the vertical corners. Boxes made of arauco ply 3/4" from Home Depot, I'm still trying to decide how I'm gonna finish them. I like the lines from the ply on front.
Ground plane, on-axis (spkr tilted down to point at the mic) 2m distance acoustic measurements look like this
THD is good on the woofer, and FR is fine to 3k, but I think that is a low baffle step from 100 to 500? Speaker is 12.5" wide. Anyway that shift ended up being around the upper of the two impedance peaks in low woofer response, that made it kinda tricky to correct passively. FR on the tweeter seems pretty nice, but measurement looks like kinda high 2nd order HD.
I've been fiddling with the XO sim to get something I like.... here's where I'm at.
Initial idea was to have the cross at 2k, but in the course if trying to make it work I have floated up from there. So I think my offset is actually a little too much, and my phase peak is a bit larger than it might have been.
If you go for this sort of XO, it is (quoted from XRK's thread)...
1. Set the low pass filter for the woofer as a 4th order Butterworth at central frequency, fc for the XO centerpoint.
2. Set the high pass filter for the tweeter as a 2nd order Bessel at fc.
3. Set the delay of the tweeter equal to 1/2 of the period of one cycle at fc.
4. Use all positive phase on woofer and tweeter.
Here's what I've learned: 2nd order -acoustic- roll off is pretty slow! 2nd order electrical is normally fine, but when you are looking at the acoustic rolloff that happens naturally that doesn't leave much space to put in electrical protection. So I ended up at higher F than I was initially targeting. It looks like 2nd order electrical on the CD but it's pretty low Q, that inductor is only helping out at lower frequencies. Impedance compensation on the CD can help you get the shape theory wants.
I think I've attached the XSIM file in case anyone wants to play along.
I'm looking forward to hearing these, but I haven't pulled the trigger on XO parts yet. Every time I buy parts a couple days later I'm like "you know what I SHOULDA done...?" so I'm still meditating on it.
What do you think?
- Adam
Iron Amp by Michael Rothacher Power supply suggestions?
- By monotube2
- Power Supplies
- 10 Replies
I would like to build this amp and I need the power supply ( about 100v 200ma on the v-fet but a bit higher because the Output transformer primary impedance ) to be particularly silent since it is connected to a compression driver with 113db of sensitivity. I was thinking of using a CLCLC power supply (to have few mV of ripple) and I was wondering if the use of a Saligny power (HVHF in this case) could be useful.
My problem is that at most I can use PSUD II and therefore I have no idea how to model a power supply with a Saligny bridge. Any suggestions?
Dynavox VR70e phono preamp - is it any good - do i need to buy one
- By jkojic
- Analogue Source
- 12 Replies
what do you guys think of this phono preamp ? i know nothing really - dont even know if its in this diagram?
Schematic or service manual Sonographe SC25
- By Dutch9600
- Analog Line Level
- 2 Replies
Trying to find out what size this resistor is in my unit. I am having trouble figuring the color code on this resistor it is in a Sonographe SC25. My unit was modded and I am going back to original, but this resistor and the cap next to it were removed and would like to replace but do not know size on both. Thanks for any and all help in advance.
Crossover Help - Dyn Heritage Special
- By kawihornet
- Multi-Way
- 36 Replies
Hey guys I was wondering if someone could draw up this crossover for me - much appreciated! I would like to do some mods to the crossover to tame the tweeter a bit.
Thanks in advance.
Thanks in advance.
Driver Recommendations - Bass/Midbass
I have been playing around with designs for a small, thin kitchen system for a while now. I have a few drivers and layouts in mind and I would like everyone's opinion. If there is a large objective difference between these I would love if you'd point them out.
Here is the frequency range I would like to use the midbass units in. The green line.
Shotting for an F3 of 38-48hz. We like bass in our house.
Here is a mockup of the design in its location. This location and temporary until we get a new house. Then it will live in the new kitchen. In the new kitchen it will be far more separated. We will not get into the design details of the rest of the system here. Just focus on midbass drivers. I'll make a thread for this build once I get a more concrete idea of what I'm doing.
The narrow baffle is key since they cannot take up a ton of counter space and I want a nice spread of sound. Probably going to be 5-7" dual woofer, 3-4" mid, 3/4" tweeter. Nice spread of sound.
Box size will be between 24-50 liters. Quite a spread I know but I could easily make it taller in a MTMWW layout or not as deep to go lower in volume.
I really want to try out dual woofers here. Originally I wanted to use these Dayton 7" drivers and I still might. I feel these are more woofer than midbass though. They are cheap. They have some decent reviews. I can get them for $45 on amazon even though they are out of stock at PE. I would dual these. These are modeled in the mockup above. Aluminum, easy to clean
Next up are these currently unobtanium Peerless 5.25" SLS. I have the 8" SLS and I love them. These are 4 ohm so we are looking at series alignment. They are low sensitivity so definitely 2 of them. They would work very well ported and I could get away with a smaller and narrower enclosure. $35 a pop when PE has them, which should be soon. Poly, easy to clean.
Another unobtanium. I always wanted a set of these. Should be available soon. Are these more of large mids than they are woofers? I like the fancy motor design, they have incredible reviews. I could use one or two of them. Two would be best with a passive radiator. This, of course, is more expensive than the last two options. $90 each and another $50 for a PR. Paper, hard to clean, maybe not best for the kitchen.
I feel these are interesting driver. I know little about Wavecor. They look cheap, they seem overpriced, they apparently measure just as well as scanspeak drivers, they model well, and the distortion graphs have very low distortion right where I want to use these. Cannot validate but read multiple times that the balanced drive is the same technology used in the revelator lineup. Same price as the NE180W. Not as cool looking but if it has better dynamics I am all over it. Would need two. Could also use the 6.5". Paper, but looks super smooth so maybe easy to clean?
Definitely need two of these in series. Not sure if these can match the lower dynamics of the other choices. They sim out well enough for the bass I want. Are these more of mid range units? Aluminum, easy to clean. Pretty pricey for a 5" at $80 a pop
Pushing the limits of the baffle allotted baffle dimensions we have this Satori unit. The 6" is unavailable. Price point dictates I only use one. Defeats my purpose of trying out multiple woofers. By far the most expensive at nearly $200. Especially for a system that will not get listened to for hours like our other systems. I hear it is only slightly better than the aforementioned Peerless with the similar motor design. Which is a rip off of which?
There are a handful of Dayton drivers like the reference series I have also looked at but none of them stand out in any way as far as measurements, price, or reviews. I see no one ever mentioning them as notably special drivers like this collection I have assembled here. If nothing else, I surely do my research.
Let me know if I should be looking at some other driver. Again, midbass dynamic and an F3 of at least 48hz is the goal here. 25-50 liters.
Here is the frequency range I would like to use the midbass units in. The green line.
Shotting for an F3 of 38-48hz. We like bass in our house.
Here is a mockup of the design in its location. This location and temporary until we get a new house. Then it will live in the new kitchen. In the new kitchen it will be far more separated. We will not get into the design details of the rest of the system here. Just focus on midbass drivers. I'll make a thread for this build once I get a more concrete idea of what I'm doing.
The narrow baffle is key since they cannot take up a ton of counter space and I want a nice spread of sound. Probably going to be 5-7" dual woofer, 3-4" mid, 3/4" tweeter. Nice spread of sound.
Box size will be between 24-50 liters. Quite a spread I know but I could easily make it taller in a MTMWW layout or not as deep to go lower in volume.
I really want to try out dual woofers here. Originally I wanted to use these Dayton 7" drivers and I still might. I feel these are more woofer than midbass though. They are cheap. They have some decent reviews. I can get them for $45 on amazon even though they are out of stock at PE. I would dual these. These are modeled in the mockup above. Aluminum, easy to clean
Next up are these currently unobtanium Peerless 5.25" SLS. I have the 8" SLS and I love them. These are 4 ohm so we are looking at series alignment. They are low sensitivity so definitely 2 of them. They would work very well ported and I could get away with a smaller and narrower enclosure. $35 a pop when PE has them, which should be soon. Poly, easy to clean.
Another unobtanium. I always wanted a set of these. Should be available soon. Are these more of large mids than they are woofers? I like the fancy motor design, they have incredible reviews. I could use one or two of them. Two would be best with a passive radiator. This, of course, is more expensive than the last two options. $90 each and another $50 for a PR. Paper, hard to clean, maybe not best for the kitchen.
I feel these are interesting driver. I know little about Wavecor. They look cheap, they seem overpriced, they apparently measure just as well as scanspeak drivers, they model well, and the distortion graphs have very low distortion right where I want to use these. Cannot validate but read multiple times that the balanced drive is the same technology used in the revelator lineup. Same price as the NE180W. Not as cool looking but if it has better dynamics I am all over it. Would need two. Could also use the 6.5". Paper, but looks super smooth so maybe easy to clean?
Definitely need two of these in series. Not sure if these can match the lower dynamics of the other choices. They sim out well enough for the bass I want. Are these more of mid range units? Aluminum, easy to clean. Pretty pricey for a 5" at $80 a pop
Pushing the limits of the baffle allotted baffle dimensions we have this Satori unit. The 6" is unavailable. Price point dictates I only use one. Defeats my purpose of trying out multiple woofers. By far the most expensive at nearly $200. Especially for a system that will not get listened to for hours like our other systems. I hear it is only slightly better than the aforementioned Peerless with the similar motor design. Which is a rip off of which?
There are a handful of Dayton drivers like the reference series I have also looked at but none of them stand out in any way as far as measurements, price, or reviews. I see no one ever mentioning them as notably special drivers like this collection I have assembled here. If nothing else, I surely do my research.
Let me know if I should be looking at some other driver. Again, midbass dynamic and an F3 of at least 48hz is the goal here. 25-50 liters.
MF nuVista M3 Refresh
- By verkion
- Tubes / Valves
- 8 Replies
Hi everyone,
I'm a fairly new (second) owner of an MF nuVista m3 amp and was thinking of doing a service on it: a) replacing the old Jamicon electrolytics and, if at all possible, removing any electrolytic caps from coupling duties; b) checking/setting/re-setting the quiescent current on the channels.
With regard to a) there is one 10uF/63V cap that I just can't find a good-sized film cap to replace it C1 and C101 on the attached diagram (Nuvista_M3_Pre-amp_Line_OP[1].pdf). The other coupling caps in the chain (C32, C40, C41 on the right channel) are already some type of film cap, yellow-coloured with a circled L logo--not sure how their quality is honestly--although I'm going to replace them with WIMA MKP10s anyways. Not all that pricey and I'll have it all apart anyways...thank goodness for suppliers like mouser and digikey etc.
Second item, b), does anyone know how "far" I should set quiescent current, i.e. bias into Class A operation? The SAP15's datasheets indicate 40mA, (so 8.8mV across pin 4,5 or 1,2 depending on N or P type), but some manufacturers seem to like "giving it a bit more." Anyone have any thoughts/experience with MF quiescent currents?
Thanks!
verkion
P.S. Attached the whole bunch of M3 Amp diagrams for people's reference. I'll be replacing PSU caps too as those are the ones that are looking "slightly fatigued." i.e. plastic cover is puckering although the metal under it feels fine...for now.
Copyrighted materials removed by moderation.
I'm a fairly new (second) owner of an MF nuVista m3 amp and was thinking of doing a service on it: a) replacing the old Jamicon electrolytics and, if at all possible, removing any electrolytic caps from coupling duties; b) checking/setting/re-setting the quiescent current on the channels.
With regard to a) there is one 10uF/63V cap that I just can't find a good-sized film cap to replace it C1 and C101 on the attached diagram (Nuvista_M3_Pre-amp_Line_OP[1].pdf). The other coupling caps in the chain (C32, C40, C41 on the right channel) are already some type of film cap, yellow-coloured with a circled L logo--not sure how their quality is honestly--although I'm going to replace them with WIMA MKP10s anyways. Not all that pricey and I'll have it all apart anyways...thank goodness for suppliers like mouser and digikey etc.
Second item, b), does anyone know how "far" I should set quiescent current, i.e. bias into Class A operation? The SAP15's datasheets indicate 40mA, (so 8.8mV across pin 4,5 or 1,2 depending on N or P type), but some manufacturers seem to like "giving it a bit more." Anyone have any thoughts/experience with MF quiescent currents?
Thanks!
verkion
P.S. Attached the whole bunch of M3 Amp diagrams for people's reference. I'll be replacing PSU caps too as those are the ones that are looking "slightly fatigued." i.e. plastic cover is puckering although the metal under it feels fine...for now.
Copyrighted materials removed by moderation.