Compact Aleph 5 module

[OliverD]

Another work in progress Aleph 5:

This time I fitted everything on one small PCB which also includes the power devices. Two parallel speaker output relais are also on the PCB (I prefer to have them). Yet to do is a PSU PCB with protection circuit. This is a quick project on a lower cost basis, although I used reasonably good components. The first picture shows the board from front, spot the Panasonic FC and silver mica caps. I used MPC71 metal band resistors, they are cheap, non-inductive and do not smoke up that easily. The IRF9610 FETs are not yet bolted to their heatsink, but the amplifier module has been tested and the typical Aleph sound could easily be recognized.

[OliverD]

The module will be mounted on a forced airflow heatsink with the PCB being attached to the sides of it. The output devices will be bolted to the top.

Top view:

[OliverD]

Input section detail. Note that I ran out of 10k resistors, so I temporarily use two 4k99 in series. All electrolytics are bypassed with film type capacitors. The zener of the input pair CCS is capacitor buffered also. At the very left and right of the board there will be two Wima MKP-10 10µF capacitors (which haven't arrived yet).

[punchpeanut]

They look great! Will you post the artwork for the pcb's? ;-)

[aaronboumans]

any change of ordering several pcb's? (holland)

[OliverD]

Will you post the artwork for the pcb's? ;-)

Yes, why not.

I'll have to prepare them for publishing, so I'll post them tonight or tomorrow.

[MKtec]

Hi AMT-Freak,

very interesting Project....could we see the shematic and the layout ?

Andre
Germany

[OliverD]

I took the schematic from Kristijan Kljucaric's site as a basis simply because the quality is better than Nelson Pass' scans:

http://web.vip.hr/pcb-design.vip/aleph-5.gif

The only things I changed were a film bypass cap for the inverting input electrolytic and the CCS zener. I used BC550C instead of MPSA18, simply because they are easier and cheaper to source here. And, as I do in all my projects, the supply is bypassed using Wima MKP-10 right on the amplifier PCB.

PCB layout and silk screen to be posted soon.

[OliverD]

Silk screen view. Note that the V+, V-, LS and GND signals are connected using AMP connectors.

[OliverD]

Here's the PCB artwork in PDF format for best compatibility. If you print it from Acrobat, make sure to uncheck all the options in the print dialog that stretch or shrink the page to get the original size.

Please be aware that it is a top (component side) view!

I get the best results printing the layout to normal paper on my laserjet and making it transparent using cooking oil.