My Aleph-X compact PCB

[Carondimonio]

Hi all,

as I would like the enter the "Alephworld", I' ve designed an Aleph-X PCB.
Due to the constraints of my PCB Editor (Eagle demo Version), the board is very compact (4" x 3.20"), and it' s not been very easy to stuff all the components on it.

Now, given that I'm not that experienced in PCB design, I would like to hear the opinion of the more knowledgeable people on this forum.
Suggestions, constructive critics, flames are all most welcome!

Cheers,

Bruno

[Carondimonio]

And here' s the driver board (4" x 1.80"):

[acaudio]

very nice

[audiotux]

Super ! javascript:smilie('')

this is a real Mini-Amp and also suitable for a X-Headphone Amp .
congrats and greetings from germany

Jürgen

[mpmarino]

<ahem><ahem> Looks good but if you post the .brd file I could get a much better look. <ahem>

[grataku]

This is pretty much identical to the 3yo standard AX board that just about everyone around here either owns or has seen.
Since everthing appears to be laid out in about the same place, if there are no mistakes, it should work.
If you are trying to actually build the amp for cheap a few people should have a bunch of the board stashed away somoene should be able to sell you a pair for no more than five dollars each. These are 4 oz Cu with the solder mask and the works. You can beat that.
Unfortunately, I am all out of mine.

[Carondimonio]

Hi all!

Thanks a lot for all the answers, it' s nice to be part of such a great community!

Originally posted by grataku
This is pretty much identical to the 3yo standard AX board that just about everyone around here either owns or has seen.
Since everthing appears to be laid out in about the same place, if there are no mistakes, it should work.

Well, given the intrinsic, simmetrical structure of the Aleph-X, I guess it would be quite difficult/illogical to lay out the parts in a totally different way. Nevertheless, there' s one difference: I added a heatsink for the input MOSFETs, to improve the thermal coupling. I know, in previous threads it has been said this is not necessary, but it makes me feel better...

Originally posted by grataku
If you are trying to actually build the amp for cheap a few people should have a bunch of the board stashed away somoene should be able to sell you a pair for no more than five dollars each.

Well, I' m not trying to build it for cheap (although I do not even want to spend a fortune), my primary goal is really to build a good amp AND to improve my personal PCB design skills. Moreover, reading other threads, it looks like there' s not many of the previous boards left, as there are other people looking for them without apparent success.

Cheers,

Bruno

[Nisbeth]

Nice work Bruno!


/U.


EDIT: I also think it would be easier to inspect the layout in detail if I had the eagle files

EDIT2: I can see you forgot to smooth the angle of the trace to C3+

[grataku]

Bruno,
the heatsink is absolutely unnecessary, I put a silpad and sqeezed the two mosfet together using a nylon screw.
These two will start dissipating enough to require heatsinking at around +/- 30V supply. You want them to get a little warm so that their temp. doesn't track RT and make the DC offset too enviroment dependent. The space would be put to better use by the addition of two nice PP input caps. which, on the other hand, I found to be absolutely necessary.

[Carondimonio]

Hi all,

thanks to you all for your comments!

I was thinking that it would be nice to have on the PCB also the two 33R, 3W resistors from output to gnd, so... well... here' s the 2nd version of the board. Any comments?

Originally posted by grataku
Bruno,
the heatsink is absolutely unnecessary, I put a silpad and sqeezed the two mosfet together using a nylon screw.
These two will start dissipating enough to require heatsinking at around +/- 30V supply. You want them to get a little warm so that their temp. doesn't track RT and make the DC offset too enviroment dependent. The space would be put to better use by the addition of two nice PP input caps. which, on the other hand, I found to be absolutely necessary.

Hi grataku, thanks a lot for your valuable input!
Well, if I do not want to use the heatsink I can always bend the pins of the two mosfets in order to squeeze them together.
As for the input caps, do you think they' re necessary if the preamp already has some caps on the outputs?

Cheers,

Bruno