Hi!
Recently made the decision to join the “Aleph club”. Although there is some very interesting pcb artwork out there, I couldn’t resist to try an own approach. This is where it ended up until now.
The board is meant to be an Aleph 5 (3 FETs paralleled, but the design can very easily be scaled for other Aleph models.
The board measures 100 x 81 millimeters (4 by 3.2 inches) and seems to be the most compact solution so far. It is, as usual, a single layer layout and I am a little proud to say that I succeeded completely without addditional wiring.
The amplifier output stage is located on the left, the current source power stage on the right side. I tried to keep the signal path as short as possible, there are for example only 54 millimeters from the speaker output terminal to the inverting input gate of the differential pair.
The diff pair may be thermally coupled, I placed the FETs back to back..
All power resistors will be Isaplan metal foil types, I’ve had some good expereiences with those. If it turns aout to be necessary, they can be mounted on a heatsink – a strip of aluminum may be sufficient.
As you can see from the artwork, I separated high from low current traces on both supply rails and the output wherever possible.
By now, the component numbering doesn’t match the standard from the aleph manual, I will change that in the future.
At the moment, all this is nothing but pure theory, and I am convinced there are a lot of errors on that design I don’t recognize at the moment, perhaps you do? Tell me what you think!
Schematics:
Recently made the decision to join the “Aleph club”. Although there is some very interesting pcb artwork out there, I couldn’t resist to try an own approach. This is where it ended up until now.
The board is meant to be an Aleph 5 (3 FETs paralleled, but the design can very easily be scaled for other Aleph models.
The board measures 100 x 81 millimeters (4 by 3.2 inches) and seems to be the most compact solution so far. It is, as usual, a single layer layout and I am a little proud to say that I succeeded completely without addditional wiring.
The amplifier output stage is located on the left, the current source power stage on the right side. I tried to keep the signal path as short as possible, there are for example only 54 millimeters from the speaker output terminal to the inverting input gate of the differential pair.
The diff pair may be thermally coupled, I placed the FETs back to back..
All power resistors will be Isaplan metal foil types, I’ve had some good expereiences with those. If it turns aout to be necessary, they can be mounted on a heatsink – a strip of aluminum may be sufficient.
As you can see from the artwork, I separated high from low current traces on both supply rails and the output wherever possible.
By now, the component numbering doesn’t match the standard from the aleph manual, I will change that in the future.
At the moment, all this is nothing but pure theory, and I am convinced there are a lot of errors on that design I don’t recognize at the moment, perhaps you do? Tell me what you think!
Schematics:
Component layout and names:
An externally hosted image should be here but it was not working when we last tested it.
Component values and artwork:
An externally hosted image should be here but it was not working when we last tested it.
Artwork only:
An externally hosted image should be here but it was not working when we last tested it.
Member
Joined 2002
Can you please send me a copy of the art work on a smaller size
at nbaula@concentric.net . Thank you
at nbaula@concentric.net . Thank you
Member
Joined 2002
@JasonL: Mail delivery failed, I'll try it agin later.
@all: Okay, I can send copies to all of you, but what's the problem with the pictures?
@all: Okay, I can send copies to all of you, but what's the problem with the pictures?
HBarske, can I have a copy of the artwork in jpeg/tiff/pdf format, please? Thanks. My email is bawang@tm.net.my
Ground soldering points?
Wouldn't it be nice to have some ground points on the layout? Large ones, like J4/5/6? Say, one near input and Zeners (for PS), another close to 220uF cap (for speaker connection)? Just a thought 🙂
BTW. I love your project. If I where to start now, I suppose I'd use your piece-of-ARTwork.
Regards,
M.
Wouldn't it be nice to have some ground points on the layout? Large ones, like J4/5/6? Say, one near input and Zeners (for PS), another close to 220uF cap (for speaker connection)? Just a thought 🙂
BTW. I love your project. If I where to start now, I suppose I'd use your piece-of-ARTwork.
Regards,
M.
Possible, of course.
But: the idea is to keep away the high current ground connections from the board, as they are not really needed here. The idea is to connect speaker to the star ground.
Perhaps I shoul add some pads for the input jacks ground connections.
Looks nice. My first observation though is that the output fets are too close to each other and would not take advantage of the heatsinks creating a hot spot.
Nice work Holger! 
that really looks nice. especially the groundplane around the low current parts.
Point of remark: It's probably just the picture, but I'm afraid about the clearance between the groundplane and the traces within it is too small.. You'll run into difficulties when etching that.
The rest looks all cool to me 🙂
Bouke
that really looks nice. especially the groundplane around the low current parts.Point of remark: It's probably just the picture, but I'm afraid about the clearance between the groundplane and the traces within it is too small.. You'll run into difficulties when etching that.
The rest looks all cool to me 🙂
Bouke
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