Moderator's Note: the thread that this was split off of:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=52188
I never thought I would ever come up with Alep layout, but ever since I've read about Pass Shoot Out In Salt Lake City, I somehow got excited about building another Aleph.
Brian was kind enough to send me the library files of his board, and I just couldn't resist the temptation to play with a layout a bit. Of course, I had never mini in mind and was aiming at Aleph 30, on one board, with minimum size.
So here we are, the size is 2.4" x 3.35" with power traces width 140mil, which should be enough for such small board. There are 6 output devices on board, and balanced inputs. All power resistors are 3W Panasonics. There is no protection diodes though.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=52188
I never thought I would ever come up with Alep layout, but ever since I've read about Pass Shoot Out In Salt Lake City, I somehow got excited about building another Aleph.
Brian was kind enough to send me the library files of his board, and I just couldn't resist the temptation to play with a layout a bit. Of course, I had never mini in mind and was aiming at Aleph 30, on one board, with minimum size.
So here we are, the size is 2.4" x 3.35" with power traces width 140mil, which should be enough for such small board. There are 6 output devices on board, and balanced inputs. All power resistors are 3W Panasonics. There is no protection diodes though.
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jleaman said:
Jason,
Calm down. Nothing is wrong with seeing Peter's alternate layout. I don't recall you asking for the files. I just sent Peter the schematic and the component libraries, and he took a fresh approach to the actual layout. I can send you the same files if you want. Drop me an e-mail and we can discuss farther.
I respect Peter's input, and it will be beneficial to get input from others regarding this project.
As far as Peter's layout, it is interesting, but I much prefer the idea of seperate output boards, as this allows for the option of running a two devices per channel to make a lower power amp, or run a higher power solution (multiple output boards will also be able to be run in parallel with the final solution as well). With the higher power solution running on a single pcb (aleph30 config), I question the ability of proper heat dissipation with 6 devices attached to a relatively small heatsink area. I guess that with proper copper heat spreader bars, reasonable thermal cooling can be obtained (or active cooling).
Anyway, I will finalize the layout for this group buy in the near future and we can order some boards together. I spoke with Nelson Pass, and have his approval to proceed with a group buy, which should be beneficial for this community.
Relax, and in the end we should have a great project for many to build.
--
Brian
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rabstg said:
I hate to point that out, but if you mount only one pair of output devices on my board (and 6 less power resistors), you will have Aleph Mini with a board measuring 2.4" x 3.35".
If you mount 3 pairs of output devices and 6 more power resistors, you will have Aleph 30, with a board still measuring 2.4" x 3.35".
If you don't mount any of the output devices (nor any power resistors), you will have front end board, good for any Aleph, with a size still 2.4" x 3.35".
All the power traces are 140mil, and are substantially shorter (in higher power application), as no additional wiring is required. This simplifies not only the assembly, but signal path as well.
If you are concerned that heat distribution might not be sufficient enough because devices are spaced too close together (which I doubt would be a problem with Aleph 30), you can still spread them further apart by attaching pieces of wire.
One additional feature in my layout is thermal coupling of input differential (as they mounted back to back, with their tabs connected), to reduce DC offset drift.
After saying that, I have no intention whatsover to start another group buy. I'm also apologizing to enter this thread with a design that might seem competeing, but it's not the case; I'm merely trying to show different options, options that I think are worth considering, especially when large number of those boards are to be distributed.
Thanks for appreaciation, Russ.
Personally, I don't think Aleph Mini should be priority in this GB. As good as it might seem, it's still very low in power, and recent Salt Lake City shootout indicates superiority of Aleph 30.
Now, what I'm trying to present here, is two channels of Aleph 30 in a package similar to LM3875 kit board. Of course PS is not on board (in case of Aleph), but only because of different requirements.
Building this Aleph shouldn't be any different than building a GC, as only one board is used, no additional wiring (that might complicate things), and small size allows variety of applications, with heatsinks being less of a limiting factor (as one can use smaller heatsinks with fan).
This brings PassLabs design into new territory, and I myself, would be very eager to try this Aleph. I made few Alephs before, but because of bigger boards, large number of devices, and complicated interface between devices and main board, I had a feeling I couldn't really reach full potential with those amps. I hope this board, with minimalistic approach to routing, where each connection and trace is short as can be, might make a very good sounding amp, an amp that could satisfy everybody who so far was not convinced about a GC.
Personally, I don't think Aleph Mini should be priority in this GB. As good as it might seem, it's still very low in power, and recent Salt Lake City shootout indicates superiority of Aleph 30.
Now, what I'm trying to present here, is two channels of Aleph 30 in a package similar to LM3875 kit board. Of course PS is not on board (in case of Aleph), but only because of different requirements.
Building this Aleph shouldn't be any different than building a GC, as only one board is used, no additional wiring (that might complicate things), and small size allows variety of applications, with heatsinks being less of a limiting factor (as one can use smaller heatsinks with fan).
This brings PassLabs design into new territory, and I myself, would be very eager to try this Aleph. I made few Alephs before, but because of bigger boards, large number of devices, and complicated interface between devices and main board, I had a feeling I couldn't really reach full potential with those amps. I hope this board, with minimalistic approach to routing, where each connection and trace is short as can be, might make a very good sounding amp, an amp that could satisfy everybody who so far was not convinced about a GC.
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There is still more possibilities. If one uses two of those boards in parallel (with front end components on one of them only), we are getting into Aleph 2. All you have to do is connect together gate and source bus lines (on both boards), while PS wires would be run separately and outputs tied together. Pretty sleek isn't it?
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I have ABSOLUTLY nothing against Peters design.
Brian's design was a direct result of Grey's post on the Mini-A.
As per Grey, "any puny transformer will work". That statement alone infers that it was to be a "small" amp/project.
Peter, your design is a totally DIFFERENT project.
The PCB you offer is a COMPLETE Aleph 30. I do NOT think that is what Grey had in mind when he suggested the Mini-A circuit.
I do hold Peters work in high regard, and from what I have seen on the forum think he is an excellent Engineer. But I do think his PCB should be classified as a different project/thread.
That is NOT saying his is good or bad, ONLY different. Stating my opinion that Peters PCB deserves it's own thread in NO way rates, judges or comments on his PCB.
It is MY OPINION that Brian/Jason’s PCB is more of what Mr. Grey intended when he shared his thoughts, and that is the spirit in which this thread started.
NONE of my posts were EVER intended as an opinion about Peter’s PCB/design or Peter as a member of this forum. I am not a hater. Peace my brotha’. (I'm disapointed there is no peace smily)..
Brian's design was a direct result of Grey's post on the Mini-A.
As per Grey, "any puny transformer will work". That statement alone infers that it was to be a "small" amp/project.
Peter, your design is a totally DIFFERENT project.
The PCB you offer is a COMPLETE Aleph 30. I do NOT think that is what Grey had in mind when he suggested the Mini-A circuit.
I do hold Peters work in high regard, and from what I have seen on the forum think he is an excellent Engineer. But I do think his PCB should be classified as a different project/thread.
That is NOT saying his is good or bad, ONLY different. Stating my opinion that Peters PCB deserves it's own thread in NO way rates, judges or comments on his PCB.
It is MY OPINION that Brian/Jason’s PCB is more of what Mr. Grey intended when he shared his thoughts, and that is the spirit in which this thread started.
NONE of my posts were EVER intended as an opinion about Peter’s PCB/design or Peter as a member of this forum. I am not a hater. Peace my brotha’.
(I'm disapointed there is no peace smily)..
rabstg said:
Actually, the pcb layout that I started and provided Peter the schematic files is exactly the same, except that the output devices are wired onto the main pcb, rather than on output boards. The idea was a scalable Aleph, rather than sticking to one particular one. Peter's A30 board is also scalable now and also can accept driver boards now.
--
Brian
Yes, it is true.
I can also ad that I would never touch it, if Brian didn't send me the schematic files. Having those, I got excited by the idea of creating a new Aleph pcb layout, a layout so compact that it would reflect GC approach. I simply couldn't help it and spend two days working o that layout.
I can also ad that I would never touch it, if Brian didn't send me the schematic files. Having those, I got excited by the idea of creating a new Aleph pcb layout, a layout so compact that it would reflect GC approach. I simply couldn't help it and spend two days working o that layout.
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