My working circuit looks exactly like in pic below. Besides the 3 elektrolytics, I didn't use any other caps. It workes fine.
You can see that output devices are not soldered yet, as it's better to solder them after they are attached to a heatsink.
I still have few of those resistors, but probably will need to order more as others might need them too.
You can see that output devices are not soldered yet, as it's better to solder them after they are attached to a heatsink.
I still have few of those resistors, but probably will need to order more as others might need them too.
An externally hosted image should be here but it was not working when we last tested it.
That was actually my objective: to make them not much bigger than GC boards 
I'm out of resistors, but I can get more. They would be $15 for a set of 24, plus shipping (probably $5).
I'm receiving another batch of boards tomorrow, so whoever ordered later, will have them delivered soon as well.
I'm out of resistors, but I can get more. They would be $15 for a set of 24, plus shipping (probably $5).
I'm receiving another batch of boards tomorrow, so whoever ordered later, will have them delivered soon as well.
Attachments
I'll definitely need some more resistors, will you let me know when you get some in?
I've just built up the first board, not tested yet but it went together really quite straight forward. I'll test the first 2 when I've built the other, hopefully this weekend if work doesn't intervene
My plan is to build two tri-amped mono blocks, 2 of the boards will be Aleph 30's the other an Aleph 3 for the tweeter.
Kev
I've just built up the first board, not tested yet but it went together really quite straight forward. I'll test the first 2 when I've built the other, hopefully this weekend if work doesn't intervene
My plan is to build two tri-amped mono blocks, 2 of the boards will be Aleph 30's the other an Aleph 3 for the tweeter.
Kev
I'll definitely need some more resistors, will you let me know when you get some in?
I've just built up the first board, not tested yet but it went together really quite straight forward. I'll test the first 2 when I've built the other, hopefully this weekend if work doesn't intervene
My plan is to build two tri-amped mono blocks, 2 of the boards will be Aleph 30's the other an Aleph 3 for the tweeter.
Kev
I've just built up the first board, not tested yet but it went together really quite straight forward. I'll test the first 2 when I've built the other, hopefully this weekend if work doesn't intervene
My plan is to build two tri-amped mono blocks, 2 of the boards will be Aleph 30's the other an Aleph 3 for the tweeter.
Kev
Just let me know how many you need and I'll order them.
In the meantime, thanks to Mr. Pass' courtesy:
http://www.diyaudio.com/forums/showthread.php?s=&postid=841733#post841733
In the meantime, thanks to Mr. Pass' courtesy:
http://www.diyaudio.com/forums/showthread.php?s=&postid=841733#post841733
I wouldnt be too happy using 2 watters for source resistors. Since its Dale's they are probably conservatively rated, so maybe they will do. In my excperience, the source resistors runs hot 
I received the boards yesterday Peter They are really nice indeed With the sneaking discussion about board ordering here at DIYaudio, I would like to add that I ordered 3 stereo sets, and shipped 2 of them to fellow diy'ers that were not able to order them for them self Whatever, the boards look even cooler in my hand than I would have thought Thanks a lot PD.
Steen
I received the boards yesterday Peter
They are really nice indeed With the sneaking discussion about board ordering here at DIYaudio, I would like to add that I ordered 3 stereo sets, and shipped 2 of them to fellow diy'ers that were not able to order them for them self Whatever, the boards look even cooler in my hand than I would have thought Thanks a lot PD.Steen
Re: Ah, the boards...
I can only offer the resistors at this point, as the whole operation was not intended as a group buy or a kit.
It started as a layout project and since it came out pretty nicely, I offer the boards to interested forum members: only throught the forum Pass Labs section.
The 3W Panasonic resistors are $15/set of 24 with shipping of $6
If interested, I can also forward the resistors Mark voluntered to donate, in that case it would be only $6 shipping. Please specify your preference by e-mail.
carpenter said:
I can only offer the resistors at this point, as the whole operation was not intended as a group buy or a kit.
It started as a layout project and since it came out pretty nicely, I offer the boards to interested forum members: only throught the forum Pass Labs section.
The 3W Panasonic resistors are $15/set of 24 with shipping of $6
If interested, I can also forward the resistors Mark voluntered to donate, in that case it would be only $6 shipping. Please specify your preference by e-mail.
On a 1Khz square wave the leading edge overshoots slightly. Is this known as "ringing"?
Anything I can do about this?
Is it a problem, I don't know what affect this ringing may have on the performance of the amp? I also don't know how to alter it.
i haven't measured the -3db point but I noticed that the amp went up to around 60KHz before the output voltage started to drop.
I'm mega chuffed that the amp is working, I made one slight mistake in understanding the thread but I soon sorted it out.
I notice that on the photo Peter put up of the populated board, that the input differential pair looked as if the sources were connected together at the tab. On mine I have to have them electrically isolated but thermally connected. Is this normal?
regards
Kev
Anything I can do about this?
Is it a problem, I don't know what affect this ringing may have on the performance of the amp? I also don't know how to alter it.
i haven't measured the -3db point but I noticed that the amp went up to around 60KHz before the output voltage started to drop.
I'm mega chuffed that the amp is working, I made one slight mistake in understanding the thread
but I soon sorted it out. I notice that on the photo Peter put up of the populated board, that the input differential pair looked as if the sources were connected together at the tab. On mine I have to have them electrically isolated but thermally connected. Is this normal?
regards
Kev
You can adjust square wave performance with C8. By changing the value of that cap (5-10pF) that "ringing" can be reduced. I didn't install the cap as I didn't care for square wave. IIRC the presence of the cap affected sonics slightly.
In my picture, the input differencial mosfets are also isolated electrically ( I used mica piece, that's why it's not well visible).
In my picture, the input differencial mosfets are also isolated electrically ( I used mica piece, that's why it's not well visible).
THanks Peter.
I've a long way to go with this yet. It's currently playing on a crappy system I've got setup in my workshop and sounding far better than it's any right to.
My god the heatsinks have their work cut out , they're not too hot to touch but I can't hold my hand on them for long. I thought my 9" x 11" heatsinks would be enough .
I'll play with C8 try to tell any sound differences, but first I'll make a case for the amp with more heatsinking.
Peter, a heartfelt thank you for making this happen, I could never afford a Pass amp any other way than DIY.
regards
Kevin
I've a long way to go with this yet. It's currently playing on a crappy system I've got setup in my workshop and sounding far better than it's any right to.
My god the heatsinks have their work cut out
, they're not too hot to touch but I can't hold my hand on them for long. I thought my 9" x 11" heatsinks would be enough . I'll play with C8 try to tell any sound differences, but first I'll make a case for the amp with more heatsinking.
Peter, a heartfelt thank you for making this happen, I could never afford a Pass amp any other way than DIY.
regards
Kevin
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