Audio Technica AT-1010 Tonearm Rebuild and Upgrades
- By jamie123
- Analogue Source
- 64 Replies
Audio Technica AT-1010 Tonearm Rebuild and Upgrades.
Having owned a PMAT-101O for some years i recently bought a used standard AT-1010 with the intentions of
rebuilding it and where i can upgrading the components.If i can match the high performance of the PMAT version i'll
be a happy bunny!
Here is the tonearm stripped into all its pieces.
The first job i wanted to tackle is to make a new bearing housing spindle bolt.The original one has a loose fit where the horizontal bearings run so i made mine with a tighter
tolerance.
The original.
8mm diameter head turned and then 6mm diameter turned for m6 thread.
Thread cut.
Here's the old with the new one which also has a 4mm hole drilled up its length for the tonearm wires to pass through.
Having owned a PMAT-101O for some years i recently bought a used standard AT-1010 with the intentions of
rebuilding it and where i can upgrading the components.If i can match the high performance of the PMAT version i'll
be a happy bunny!
Here is the tonearm stripped into all its pieces.
The first job i wanted to tackle is to make a new bearing housing spindle bolt.The original one has a loose fit where the horizontal bearings run so i made mine with a tighter
tolerance.
The original.
8mm diameter head turned and then 6mm diameter turned for m6 thread.
Thread cut.
Here's the old with the new one which also has a 4mm hole drilled up its length for the tonearm wires to pass through.
Hello from PA
- By Stiglite
- Introductions
- 1 Replies
Hello all,
I have joined this forum so I can learn and or possibly help someone else on the never ending audio journey. My current system...
Yamaha RX-A8A in a 7.2.4 setup
Macintosh MC7106 powers the surrounds
Proceed HPA 3 triple mono powers the front and center channels
Polk R700 mains, R400 center, R200 rear surrounds.
In wall side surrounds 3 way monolith 8"
4 8" Monolith angled Atmos speakers
1 Rythmik FV18
1 Bic 12"
LG 65 Oled inch TV
My next project is to build 2 subwoofers. I have been considering a couple Mini Marty's with the new Ultimax or possibly the Stereo Integrity HST18.
This site is a great resource of information and I'm looking learning new things and enjoying the journey..
I have joined this forum so I can learn and or possibly help someone else on the never ending audio journey. My current system...
Yamaha RX-A8A in a 7.2.4 setup
Macintosh MC7106 powers the surrounds
Proceed HPA 3 triple mono powers the front and center channels
Polk R700 mains, R400 center, R200 rear surrounds.
In wall side surrounds 3 way monolith 8"
4 8" Monolith angled Atmos speakers
1 Rythmik FV18
1 Bic 12"
LG 65 Oled inch TV
My next project is to build 2 subwoofers. I have been considering a couple Mini Marty's with the new Ultimax or possibly the Stereo Integrity HST18.
This site is a great resource of information and I'm looking learning new things and enjoying the journey..
DATS V3, REW Impedance Measurements, FlexASIO
- By actualJP
- Equipment & Tools
- 15 Replies
My DATS is fun to play with, but I hate the application that runs it, and it only runs on Windows. It's easy enough to export an impedance sweep to a text file and draw pretty graphs with REW, though. I am also playing with 3rd-party ASIO control panels, and on a recent fresh Windows install, I got Windows running, added FlexASIO before I installed the DATS software, and something interesting popped up in REW Preferences:
Drivers: ASIO
ASIO Device: FlexASIO
[Control Panel]
Driver Type: Windows WASAPI
Input Device:
It looks like if I select the Loopback input device, it only puts sound on the "left" channel, so I can't get Input and Reference Input to lift on the level meter at the same time. If I select the non-Loopback input device, and just set REW preferences like any other stereo interface, the calibration procedure works as expected. I can get a sound card calibration measurement.
The V3 (rev H) box has a 1KOhm resistor with lugs built into the nose of the chassis. Is there any hope that I can use this "black box" hardware to take impedance measurements with REW natively? I've already been inside the case before to fix a loose post, and it's pretty dull inside with very compact SMC devices and only a couple of ICs on the board. I'd be happy to break it open again and document anything that I can identify, though.
I do have a Behringer UMC202HD, and it's installed and configured but not attached, so it's not listed in the control panels above.
Drivers: ASIO
ASIO Device: FlexASIO
[Control Panel]
Driver Type: Windows WASAPI
Input Device:
Line (USB AUDIO CODEC)
Internal Microphone (Cirrus (AB54))
Speakers (Cirrus (AB54)) [Loopback]
Speakers (USB AUDIO CODEC) [Loopback]
Output Device:Speakers (Cirrus (AB54))
Speakers (USB AUDIO CODEC)
It looks like if I select the Loopback input device, it only puts sound on the "left" channel, so I can't get Input and Reference Input to lift on the level meter at the same time. If I select the non-Loopback input device, and just set REW preferences like any other stereo interface, the calibration procedure works as expected. I can get a sound card calibration measurement.
The V3 (rev H) box has a 1KOhm resistor with lugs built into the nose of the chassis. Is there any hope that I can use this "black box" hardware to take impedance measurements with REW natively? I've already been inside the case before to fix a loose post, and it's pretty dull inside with very compact SMC devices and only a couple of ICs on the board. I'd be happy to break it open again and document anything that I can identify, though.
I do have a Behringer UMC202HD, and it's installed and configured but not attached, so it's not listed in the control panels above.
-
Locked
JFE2140/OPA192 jFET/MOS phono preamp with "tube" THD spectrum
- By Nick Sukhov
- Analogue Source
- 123 Replies
Original QUAD ESL wood (or not)
- By wout31
- Planars & Exotics
- 4 Replies
There is talk about spider legs and stack constructions for the original Quad ESL, but little talk about the original feet.
Some make something that looks a bit like the original feet which are often lots or bad or damaged etc.
I took the 100% original design and 3D printed the feet, re-inforced it with a 6 mm aluminium rod for strength.
PLA is available in various wood resembling colours and the mounting plate is black like the originals.
Some make something that looks a bit like the original feet which are often lots or bad or damaged etc.
I took the 100% original design and 3D printed the feet, re-inforced it with a 6 mm aluminium rod for strength.
PLA is available in various wood resembling colours and the mounting plate is black like the originals.
A great power reducing headphone adapter for vintage power amps
- By wparks
- Headphone Systems
- 4 Replies
I have been restoring vintage amplifiers from consoles and 8-track players, and turning them into stand-alone components. These old chassis don't have headphone outputs. I have no intention of modifying them to install this output, but I do want the ability to listen to them post-restoration and evaluate more accurately the sound quality with headphones. I can hear more detail that way, and in general the differences in sound quality between amplifiers can be subtle.
I ran across a great design from Rod Elliott's ESP website, project 100, "Headphone Adapters for Power Amplifiers" that provides a simple design that safely reduces the output power to a safe level. The schematic below (for version 1) is accompanied by a table of optimal values of R1 and R3 for the nominal output power rating of the amplifier, to provide a headphone output limited to 5Vrms and a 120Ω output impedance. He also offers a version 2 with a ~2Ω output impedance, but it requires much higher wattage (10-40W) resistors which are more expensive and require more cooling consideration. (If you want to debate about whether 120Ω output impedance should be used with modern headphones, I'll put my opinion on this at the bottom to minimize distraction here)
The adapter circuit provides a light loading to the amplifier of several hundred ohms, which most if not all amplifiers will tolerate well (yes, even most reasonably tuned tube amps). The voltage divider reduces the output amplitude, and R3 tunes the output impedance. Note that this adapter can only be used with ground referenced outputs (most are), and absolutely not with BTL (Bridge Tied Load) amplifiers as the negative side of Left and Right are shorted together at the headphone socket. Actual output volume of the headphones driven by this circuit depends upon their impedance. My favorite phones are 32Ω and 50Ω and this circuit provides adequate volume for these, which are considered harder to drive adequately.
I eliminated the DPDT switch, as my assembly was to be used as a temporary test adapter, connected instead of the speakers. The accompanying table on Rod's page provides values for 10W to 250W power amplifiers, with the recommendation to use the values for a higher wattage amp if you want less output to your phones and vice versa. He gives power ratings for R1, but not R2=120Ω. I would recommend a 1W at least for that. R3 can be rather small, I used 1/2W for that.
Most of the amplifiers I rebuild are 25W per channel or less, but I used the value for 40W (R1=330Ω, R3=33Ω) as I really don't need much power.
I tacked together a temporary test version to make sure I was happy with the output level across several amplifiers. For high wattage amplifiers, you simply use it with the volume at lower levels. Given I selected values for a 40W output, I found that with a 12W and even a flea power 4W amp I was still able to achieve robust volume out of my 32Ω phones, but had to turn the volume nearly all the way up. Given that I was tempted to drop down to the 20W values, but I may want to use this with 50W and 100W amps and still have some volume control, so I think this is a good tradeoff.
OK - My take on the hotly debated 120Ω source impedance for headphones question. Most consumer amplifiers typically have just a series resistor between the output and the headphone jack. I have seen anywhere from 100Ω to 500Ω, typically higher resistances for higher output wattage. This was a cheap and dirty way to limit the available power so you were less likely blow up your phones, heard less noise, and could listen at some reasonable low output for a low volume setting. Since headphone impedances are all over the place, standardizing on 120Ω was the best one-size-fits-all compromise. I think this is where the 120Ω standard came from (to ensure basic compatibility) more than some exacting audiophile concern about driver damping factor. Obviously voltage amplitude is lost across the 120Ω, so to use it you have to drive a higher voltage amplitude out of the headphone amp. This is very difficult for todays portable low voltage battery powered headphone outputs, most of which are very low power output op-amp drivers. There is not enough output power to worry about limiting damage, so modern equipment skips the 120Ω output impedance and typically has very low (single digit Ω) output impedance. However, whether headphone manufacturers have actually changed their designs to work "optimally" with this is questionable. Unless they are high end headphones that explicitly state the optimal impedance, it probably was not even a consideration.
Obviously, you will have a lower damping factor for 120Ω, resulting in a fatter, less controlled or warmer/softer bass. For ~0Ω output with a higher damping factor, you should have tighter, more controlled, accurate bass. This is obviously more important for speakers, which have much higher moving mass and momentum than a headphone diaphram. Whether the different damping factor will be audible, and which sounds better to you with your particular headphones, however, will require experimentation. Personally, I have found very little difference at least to my ears between the two impedances.
I ran across a great design from Rod Elliott's ESP website, project 100, "Headphone Adapters for Power Amplifiers" that provides a simple design that safely reduces the output power to a safe level. The schematic below (for version 1) is accompanied by a table of optimal values of R1 and R3 for the nominal output power rating of the amplifier, to provide a headphone output limited to 5Vrms and a 120Ω output impedance. He also offers a version 2 with a ~2Ω output impedance, but it requires much higher wattage (10-40W) resistors which are more expensive and require more cooling consideration. (If you want to debate about whether 120Ω output impedance should be used with modern headphones, I'll put my opinion on this at the bottom to minimize distraction here)
The adapter circuit provides a light loading to the amplifier of several hundred ohms, which most if not all amplifiers will tolerate well (yes, even most reasonably tuned tube amps). The voltage divider reduces the output amplitude, and R3 tunes the output impedance. Note that this adapter can only be used with ground referenced outputs (most are), and absolutely not with BTL (Bridge Tied Load) amplifiers as the negative side of Left and Right are shorted together at the headphone socket. Actual output volume of the headphones driven by this circuit depends upon their impedance. My favorite phones are 32Ω and 50Ω and this circuit provides adequate volume for these, which are considered harder to drive adequately.
I eliminated the DPDT switch, as my assembly was to be used as a temporary test adapter, connected instead of the speakers. The accompanying table on Rod's page provides values for 10W to 250W power amplifiers, with the recommendation to use the values for a higher wattage amp if you want less output to your phones and vice versa. He gives power ratings for R1, but not R2=120Ω. I would recommend a 1W at least for that. R3 can be rather small, I used 1/2W for that.
Most of the amplifiers I rebuild are 25W per channel or less, but I used the value for 40W (R1=330Ω, R3=33Ω) as I really don't need much power.
I tacked together a temporary test version to make sure I was happy with the output level across several amplifiers. For high wattage amplifiers, you simply use it with the volume at lower levels. Given I selected values for a 40W output, I found that with a 12W and even a flea power 4W amp I was still able to achieve robust volume out of my 32Ω phones, but had to turn the volume nearly all the way up. Given that I was tempted to drop down to the 20W values, but I may want to use this with 50W and 100W amps and still have some volume control, so I think this is a good tradeoff.
OK - My take on the hotly debated 120Ω source impedance for headphones question. Most consumer amplifiers typically have just a series resistor between the output and the headphone jack. I have seen anywhere from 100Ω to 500Ω, typically higher resistances for higher output wattage. This was a cheap and dirty way to limit the available power so you were less likely blow up your phones, heard less noise, and could listen at some reasonable low output for a low volume setting. Since headphone impedances are all over the place, standardizing on 120Ω was the best one-size-fits-all compromise. I think this is where the 120Ω standard came from (to ensure basic compatibility) more than some exacting audiophile concern about driver damping factor. Obviously voltage amplitude is lost across the 120Ω, so to use it you have to drive a higher voltage amplitude out of the headphone amp. This is very difficult for todays portable low voltage battery powered headphone outputs, most of which are very low power output op-amp drivers. There is not enough output power to worry about limiting damage, so modern equipment skips the 120Ω output impedance and typically has very low (single digit Ω) output impedance. However, whether headphone manufacturers have actually changed their designs to work "optimally" with this is questionable. Unless they are high end headphones that explicitly state the optimal impedance, it probably was not even a consideration.
Obviously, you will have a lower damping factor for 120Ω, resulting in a fatter, less controlled or warmer/softer bass. For ~0Ω output with a higher damping factor, you should have tighter, more controlled, accurate bass. This is obviously more important for speakers, which have much higher moving mass and momentum than a headphone diaphram. Whether the different damping factor will be audible, and which sounds better to you with your particular headphones, however, will require experimentation. Personally, I have found very little difference at least to my ears between the two impedances.
CRESCENDO S1 PLUS U20 NOT HAVE
- By joselorenzo
- Car Audio
- 1 Replies
Hi .
I am looking for information on a Crescendo S1 Plus amplifier. It seems that U20 was removed from the power supply stage.
Does anyone have any idea or information on what integrated circuit it has?
I am looking for information on a Crescendo S1 Plus amplifier. It seems that U20 was removed from the power supply stage.
Does anyone have any idea or information on what integrated circuit it has?
Attachments
Class D Type 4 very high distortion issue
Hi,
I’m working on a clone BASSFACE class D Type 4 amplifier that was brought in with a burnt-out power supply and a dead output section.
It’s using 10 IRF260Ns for its output.
After fixing the power supply, I noticed the drive waveform on the output had a step on the turn-on, and the low-side FETs were running hot without a load at idle.
I changed the driver transistors from 2316, 916 to 2073, 940 respectively, and doing so solved the problem with the drive waveform. However, the amplifier was getting distortion well before the clipping point. The driver transistors on the low side, especially the 2073, were also running hot when I did this. I switched back to the original drivers to see if the distortion was also present with them fitted, and indeed it was, and it was much worse.
I also tried leaving the 2073, 940 on the high side and the original transistors on the low side, which was somewhat better. I also tried other transistors like 649, 669, and the results were much worse.
Any idea on what is causing this and how I can fix it?
Any help would be greatly appreciated. (I’m kind of new to fixing class D amps 😅)
Also, the rail voltage is 180 peak-to-peak.
I’m working on a clone BASSFACE class D Type 4 amplifier that was brought in with a burnt-out power supply and a dead output section.
It’s using 10 IRF260Ns for its output.
After fixing the power supply, I noticed the drive waveform on the output had a step on the turn-on, and the low-side FETs were running hot without a load at idle.
I changed the driver transistors from 2316, 916 to 2073, 940 respectively, and doing so solved the problem with the drive waveform. However, the amplifier was getting distortion well before the clipping point. The driver transistors on the low side, especially the 2073, were also running hot when I did this. I switched back to the original drivers to see if the distortion was also present with them fitted, and indeed it was, and it was much worse.
I also tried leaving the 2073, 940 on the high side and the original transistors on the low side, which was somewhat better. I also tried other transistors like 649, 669, and the results were much worse.
Any idea on what is causing this and how I can fix it?
Any help would be greatly appreciated. (I’m kind of new to fixing class D amps 😅)
Also, the rail voltage is 180 peak-to-peak.
UAC2.0 on STM32
- By EvSap
- Digital Line Level
- 287 Replies
Hello! I am trying to make USB Audio class 2 device based on STM32 MCU.
Hardware: a board with STM32F722 and external USB HS PHY.
Software: USB Audio class 1 example from ST as a base. I changed USB desctriptor and add code for new entites requests and made board work in HS mode. But in device manager in Windows the device appears with exclamation mark. USB Descriptor analyzer shows no errors. USB traffic analyzer shows no errors. But after some actions on the bus - IOCTL_USB_GET_DEVICE_CHARACTERISTICS (ioctl 0x00220480) 134, 135 positions in log - the device gets "Surprise Removal". Investigating MCU software by means of debugger ended up without any certain results: application is running, no faults detected.
I am confused by this situation and do not know what further steps I should take to get the device enumerated properly. Any help would be much appriciated.
Hardware: a board with STM32F722 and external USB HS PHY.
Software: USB Audio class 1 example from ST as a base. I changed USB desctriptor and add code for new entites requests and made board work in HS mode. But in device manager in Windows the device appears with exclamation mark. USB Descriptor analyzer shows no errors. USB traffic analyzer shows no errors. But after some actions on the bus - IOCTL_USB_GET_DEVICE_CHARACTERISTICS (ioctl 0x00220480) 134, 135 positions in log - the device gets "Surprise Removal". Investigating MCU software by means of debugger ended up without any certain results: application is running, no faults detected.
I am confused by this situation and do not know what further steps I should take to get the device enumerated properly. Any help would be much appriciated.
For Sale 2 x AD1862-N including varoius Miro dac board's and PSU's
- By Chrisr3521
- Swap Meet
- 2 Replies
I'm going in a different direction now so have for sale,
2 x AD1862-N dac chips NOS
2 x Miro 1862 dac boards
1 x pcm56p dac board
1 x pcm58p board
1 x tda1541a psu board
2 x Vunces dac iv stage boards
2 x miro psu board
1 x spidif / optical to is2 board including crystal
£70 plus postage to wherever you are in the world.
I'm sure that I bought the shift registers for the 1862 dacs if I can find them I'll include them.
2 x AD1862-N dac chips NOS
2 x Miro 1862 dac boards
1 x pcm56p dac board
1 x pcm58p board
1 x tda1541a psu board
2 x Vunces dac iv stage boards
2 x miro psu board
1 x spidif / optical to is2 board including crystal
£70 plus postage to wherever you are in the world.
I'm sure that I bought the shift registers for the 1862 dacs if I can find them I'll include them.
MAX4466 Electret Microphone Pre-amplifier Module + SSM2167 Voice Compression
- By jjasniew
- Instruments and Amps
- 0 Replies
Anyone use one of these? I have two in hand. Bet you could get it to work with a dynamic mic as well - just accommodate the electret bias current, cap decouple to the Vcc/2 signal midpoint. Specs on the IC parts seem impressive for the $10 decade of expenditure. Ok, it's not a $35k Fairchild 660, but maybe with some I/O transformers? One would think you could build it right into the mic and have a vocal mic that "just does it".
Finding the right listening position
- By zyodmusic
- Room Acoustics & Mods
- 15 Replies
Hey everyone, my first post here. I´ve just moved in a new mixing room and are currently trying to find the best listening position. I attach a sketch of the room, which has already a lot of absorption installed. I use the Yamaha HS7 in my setup and placing them as close to the front wall as possible to get the most bass out of it and to remove almost all front wall SBIR. I already made some measurements using REW, where in each measurement the monitor is moved around 20 cm inwards from the side wall but keeping the short front wall distance. Blue (1st measurement), Orange 2nd, Green 3rd, Purple 4th.
What do you think? Thanks!
What do you think? Thanks!
PP ECL82 amp with cascode inverter
- By P100
- Tubes / Valves
- 18 Replies
Hello everyone,
I recently looked into boxes of tubes that I collected over the years and found out to have 20 ECL82/6F3P/PCL82. Some of these look slightly used, but others are crystal clear (even NOS in boxes). I would like to build a guitar amp for a clean jazzy tone, getting around 6-7W in PP would be more than fine for me.
I would like to make a hybrid construction rather than making another clone of something common (I have already built amps in the past so I know something). I like the idea of having only 2 bottles for the whole amp. Since hybrid amps are new for me, I would like to deepen this topic and learn something new, so I decided to ask here for some pro tips 🙂
When I started thinking about the design, I came up with an idea of using hybrid cascode in the inverter, with JFETs as lower devices. Quick simulation of such a design has shown that plenty of gain is achieved (obvious) and it might work. Also found this thread:
https://www.diyaudio.com/community/threads/calling-yves.102553/
where gingertube mentioned such a configuration for ECL82.
I have a PT dedicated for ECL/PCL tubes, which has a 13V tap for PCL heaters. I can use 13V to obtain -15V for the purpose of CCS and preamp section. However, my concern is feedback, I would like to tame the gain but have no clue how to make it properly. Initial idea was to apply GNF from the OT to the "+" input of a differential opamp driving the inverter, but I am not sure this is a good way of doing it (long feedback path?). Besides, due to 0:-15V supply I would have to create artificial ground for opamps so using transistor stages might be a better idea. I was fooling around plate-to-plate feedback from output tubes to the inverter (shortest path), but could not get meaningful results in spice. I also consider using UL...
Regarding preamp, I want to have simple low/high correction and rather flat characteristics. Since cascode provides a lot of gain, the preamp section would not have to deliver a lot of amplification (at least that's how I see it). Maybe experienced users of this board could suggest something to me? Since this will be a guitar amp, the THD is not the most important matter.
Here's the schematics I've been working on.
I recently looked into boxes of tubes that I collected over the years and found out to have 20 ECL82/6F3P/PCL82. Some of these look slightly used, but others are crystal clear (even NOS in boxes). I would like to build a guitar amp for a clean jazzy tone, getting around 6-7W in PP would be more than fine for me.
I would like to make a hybrid construction rather than making another clone of something common (I have already built amps in the past so I know something). I like the idea of having only 2 bottles for the whole amp. Since hybrid amps are new for me, I would like to deepen this topic and learn something new, so I decided to ask here for some pro tips 🙂
When I started thinking about the design, I came up with an idea of using hybrid cascode in the inverter, with JFETs as lower devices. Quick simulation of such a design has shown that plenty of gain is achieved (obvious) and it might work. Also found this thread:
https://www.diyaudio.com/community/threads/calling-yves.102553/
where gingertube mentioned such a configuration for ECL82.
I have a PT dedicated for ECL/PCL tubes, which has a 13V tap for PCL heaters. I can use 13V to obtain -15V for the purpose of CCS and preamp section. However, my concern is feedback, I would like to tame the gain but have no clue how to make it properly. Initial idea was to apply GNF from the OT to the "+" input of a differential opamp driving the inverter, but I am not sure this is a good way of doing it (long feedback path?). Besides, due to 0:-15V supply I would have to create artificial ground for opamps so using transistor stages might be a better idea. I was fooling around plate-to-plate feedback from output tubes to the inverter (shortest path), but could not get meaningful results in spice. I also consider using UL...
Regarding preamp, I want to have simple low/high correction and rather flat characteristics. Since cascode provides a lot of gain, the preamp section would not have to deliver a lot of amplification (at least that's how I see it). Maybe experienced users of this board could suggest something to me? Since this will be a guitar amp, the THD is not the most important matter.
Here's the schematics I've been working on.
Heil AMT frequency response, does this look normal?
- By bourbon-neat
- Multi-Way
- 12 Replies
I used REW to measure the frequency response of a Heil AMT outside on a 6' ladder, I restricted the sweep to 500-20,000Hz, used 4.6ms gating and no smoothing, the mic was 1M from the driver. Is it supposed to look this lumpy or is this AMT broken? I'm not worried about the rising response just the lumpiness.
For Sale Tektronix 575 and 577 D1 Curve Tracers
The 575 is Sold
The 577 is tentatively sold
The 575 has the MOD122C (400V collector) option.
The 577 is the storage version with option 10 (10 x 10 cm graticule).
Both are clean inside and out.
Both are working, the brightness of the 575 is sufficient to display a trace but not as bright as the 577.
The storage function on the 577 is working.
Both include Tek carts & operation & service manuals, the manuals have the info for the Mod122C (575) and option 10 (577).
PM me for info or additional pictures.
The 575 I absolutely can not ship, the 577 I could, but I would really prefer local pickup. I'm in the Waukesha WI area.
$250 for the 575, $550 for the 577.
The 577 is tentatively sold
The 575 has the MOD122C (400V collector) option.
The 577 is the storage version with option 10 (10 x 10 cm graticule).
Both are clean inside and out.
Both are working, the brightness of the 575 is sufficient to display a trace but not as bright as the 577.
The storage function on the 577 is working.
Both include Tek carts & operation & service manuals, the manuals have the info for the Mod122C (575) and option 10 (577).
PM me for info or additional pictures.
The 575 I absolutely can not ship, the 577 I could, but I would really prefer local pickup. I'm in the Waukesha WI area.
$250 for the 575, $550 for the 577.
DSP-Choice for 3 Way Crossover Design
- Digital Line Level
- 7 Replies
Hey there,
I'm quite new here and one could say a total beginner when it comes to the digital world of Hifi.
But before I dive in too deep (which I'm more than willing to do), I was hoping of getting some advice on the general direction I'm heading.
Below I have sketched my preferred setup for a current speaker project I've also posted in the "planars & exotics" section:
Believe it or not I've read quite a lot about the possibilities on designing the Crossover, but since there are a lot of different routes and pros and cons, my head is still buzzing.
Below are a few general options I've seen so far:
option 1:
use 2x adau1701-boards and program via SigmaStudio
(cons: ADC and DAC quality seems to be very poor, clocking of external DAC seems to be tricky)
option 2:
use of rasperryPi + Hifiberry DAC8x and control via CamillaDSP
(cons: at first glance quite complex, haven't understood what's happening on the input side)
option 3:
stay analogue with an active crossover
(limited options when it comes to Room correction etc if I want to stay on a butget)
as you probably see, I'm in a very early stage of this rabbit-hole so maybe I've also missed the obvious solution, which is why I was hoping for some guidance for the next steps to undertake.
Thanks in advance and I hope I'm not underchallenging you guys 🙂
I'm quite new here and one could say a total beginner when it comes to the digital world of Hifi.
But before I dive in too deep (which I'm more than willing to do), I was hoping of getting some advice on the general direction I'm heading.
Below I have sketched my preferred setup for a current speaker project I've also posted in the "planars & exotics" section:
Believe it or not I've read quite a lot about the possibilities on designing the Crossover, but since there are a lot of different routes and pros and cons, my head is still buzzing.
Below are a few general options I've seen so far:
option 1:
use 2x adau1701-boards and program via SigmaStudio
(cons: ADC and DAC quality seems to be very poor, clocking of external DAC seems to be tricky)
option 2:
use of rasperryPi + Hifiberry DAC8x and control via CamillaDSP
(cons: at first glance quite complex, haven't understood what's happening on the input side)
option 3:
stay analogue with an active crossover
(limited options when it comes to Room correction etc if I want to stay on a butget)
as you probably see, I'm in a very early stage of this rabbit-hole so maybe I've also missed the obvious solution, which is why I was hoping for some guidance for the next steps to undertake.
Thanks in advance and I hope I'm not underchallenging you guys 🙂
Does anyone make custom toroidal power transformers in singles?
- By rickcl
- Solid State
- 21 Replies
Attachments
SB Acoustics SB34NRXL75-8 vs SB29NRX75-6 vs SB29NRX75-8
I did some measurements today of these 3 drivers in closed volumes. In my measurement room, 0,5m distance groundplane - so there is a little rrom influence left, but good enough for a comparison. Level is corrected for 1m freefield.
First SB34NRXL75-8. One of the best drivers I know, especially for that money. Very good use for a 3-way but could also be a subwoofer.
THD is incredible low - 1% at 105-110dBSpl! I use 2 of them in my new speakers ... that's enough for most rooms ;-)
Also 0,05% THD ... not often I measure that with a speaker!
Now SB29NRX75-6. My goto chassis for closed subwoofers, put 6 of them in my homecinema as SBA. Not expensive, doesn't need a big volume, not to heavy membrane, huge venting hole, 75mm coil, not to heavy membrane, noise free Xmax.
Frequency response already shows us this is no midrange chassis. THD is good at low frequencies but doesn't scale as it should at low levels! I know this behaviour from PA chassis, didn't expect it here. No problem for a woofer - but I would not use it up to a few hundred Hz.
And now the SB29NRX75-8. I expected something in the middle between these 2 according the datasheet - a smaller and cheaper alternative to the 12".
Nope - that's not what I need for a low mid driver. The same THD behaviour - it looks like about the same driver just with higer impedance coil.
All of these drivers had no problem at all with 25V -> 80W/8R sine power, you need a bigger amp as an AHB-2 to bring them to their limits.
SB Acoustics has some gems in their programm but their "normal" driver range can't compete with the best from ScanSpeak. They are half of the price - it's probably ok ;-)
I still recommend the SB29NRX75-6 for subwoofers - huge coil and perfect venting, these drivers can take power!
But their SB34NRXL75-8 ... is one of these gems. One of the best 12" available.
First SB34NRXL75-8. One of the best drivers I know, especially for that money. Very good use for a 3-way but could also be a subwoofer.
THD is incredible low - 1% at 105-110dBSpl! I use 2 of them in my new speakers ... that's enough for most rooms ;-)
Also 0,05% THD ... not often I measure that with a speaker!
Now SB29NRX75-6. My goto chassis for closed subwoofers, put 6 of them in my homecinema as SBA. Not expensive, doesn't need a big volume, not to heavy membrane, huge venting hole, 75mm coil, not to heavy membrane, noise free Xmax.
Frequency response already shows us this is no midrange chassis. THD is good at low frequencies but doesn't scale as it should at low levels! I know this behaviour from PA chassis, didn't expect it here. No problem for a woofer - but I would not use it up to a few hundred Hz.
And now the SB29NRX75-8. I expected something in the middle between these 2 according the datasheet - a smaller and cheaper alternative to the 12".
Nope - that's not what I need for a low mid driver. The same THD behaviour - it looks like about the same driver just with higer impedance coil.
All of these drivers had no problem at all with 25V -> 80W/8R sine power, you need a bigger amp as an AHB-2 to bring them to their limits.
SB Acoustics has some gems in their programm but their "normal" driver range can't compete with the best from ScanSpeak. They are half of the price - it's probably ok ;-)
I still recommend the SB29NRX75-6 for subwoofers - huge coil and perfect venting, these drivers can take power!
But their SB34NRXL75-8 ... is one of these gems. One of the best 12" available.
uTracer 3+ How do I measure double triodes, curve tracing, and emission vs GM?
- By Pegasus123
- Tubes / Valves
- 12 Replies
My uTracer 3+ is complete and it works perfectly when wired for a triode.
1) The manual states that I should be able to test both triodes of a 12AU7 by connecting the second anode to the screen. When I do this I get nothing, is there something I am missing?
2) When attempting to curve trace I keep getting a compliance error and the triode trace plummets to the bottom of the graph. Should I just set the Compliance at 200ma even though the data sheet stops at 35ma? Do I risk damaging the tube?
3) Some of my triodes measure at 100% plate, 100% transconductance, 100% MU, and 87% emissions on the quick test. The same tube on a Hickok made TV-7 measured above 100%. If the TV-7 mainly just tests transconductance and is practically the gold standard, how worried should I be of the emissions rating? Also, some of my tubes have 56% emissions but otherwise test well.
1) The manual states that I should be able to test both triodes of a 12AU7 by connecting the second anode to the screen. When I do this I get nothing, is there something I am missing?
2) When attempting to curve trace I keep getting a compliance error and the triode trace plummets to the bottom of the graph. Should I just set the Compliance at 200ma even though the data sheet stops at 35ma? Do I risk damaging the tube?
3) Some of my triodes measure at 100% plate, 100% transconductance, 100% MU, and 87% emissions on the quick test. The same tube on a Hickok made TV-7 measured above 100%. If the TV-7 mainly just tests transconductance and is practically the gold standard, how worried should I be of the emissions rating? Also, some of my tubes have 56% emissions but otherwise test well.