PA03 Pavel Dudek gainclone build

[bk856er]

I posted some build pics in the group buy area, but thought this was a better home for my PA03 Pavel Dudek gainclone build - my first chip amp.

Finished last week and it's been working great. Very quiet. Added the front LED today, so now it's really done. 😀

Some details of this compact "blacked out beauty":

- diyA store Galaxy 2U 230x230mm case with fully vented top.
- Carefully matched resistors where called for.
- Beefy new/surplus 6A medical grade input filter.
- Antek AS-2224 shielded 200VA 2x24V trafo.
- HeatsinkUSA 5.375 profile @ 2.5"
- Heatsink tops out at ~50C.
- Balanced inputs.

Thanks to Pavel for the design and P-A for the board!

BK

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[AndrewT]

I like the complete separation of the PSU from the audio using the heatsink as a gap filler.
The P.D. layout is good.

 

[thuanth43]

That is one huge filter. Great compact build.

 

[bk856er]

Proud to have the biggest most stout filter on the block - no filter envy here! It's a "medical" type without Y caps and allegedly less prone to audio issues. Big stack of new ones at my local surplus place and I couldn't resist @ $4.

It's this one: PE000DL6C TE Connectivity Corcom Filters | Connectors, Interconnects | DigiKey

BK

 

[AndrewT]

removing the Y caps is done for Medical Safety. Don't kill the patient !

That removal of the Y caps reduces the performance of the filter.

 

[bk856er]

I can live with reduced filter performance. For me it's mainly a convenient and cheap fuse holder.

There was some good adult discussion of the topic and sims here and also some good reference material here and here. I chose to avoid Y caps for this application.

BK

 

[shaffenmeister]

Hi BK,

could you please tell me which capacitors you used for C9 (47pF/100V) and C11 (47yF/16V)?


Thanks in advance,

C.

 

[AndrewT]

47pF could be either NPO or plastic film.
47uF would be electrolytic.

 

[bk856er]

Hi BK,

could you please tell me which capacitors you used for C9 (47pF/100V) and C11 (47yF/16V)?


Thanks in advance,

C.

From my notes (Mouser #s):

C9 = 140-500N5-470J-RC
C11 = 505-MKS21.0/63/5

BK

 

[bk856er]

From my notes (Mouser #s):

C9 = xxx
C11 = xxx

BK

Well, apparently my notes were inaccurate and I made substitutions at the time of order. My apologies for the incorrect info above. Below is what I actually ordered from Mouser after looking up the invoice:

C9 = 75-561R10TCCQ47
C11 = 555-RFS16V470MG3#5

BK