Interesting one piece EL34 PP tube amp diy pcb on ebay

[tomlang]

Suggests using 12ax7 and 12au7 tubes but with resistor changes others can be used. The filaments are NOT on the board (good), nor is the full wave bridge but does use long tail pair (alas, no ccs) and bias circuit for adjusting each output tube. No affiliation of course, but seemed like a fun "all-in-one" solution for those so inclined to build a 6l6, el34, even 6v6 amp. Both boards below are from the same seller but the one in German shows the schematic.

http://www.ebay.com/itm/190888847849?ss ... 1438.l2649

http://www.ebay.com/itm/1-Stuck-vergold ... 2ec9467bb9

[Shannon Parks]

Here's the schematic.

Shannon

[Geek]

Can't get much more generic than that

Problem with a PCB is modding is difficult and always looks a mess

[tomlang]

Hi Geek, one of your current sink/source boards could be substituted for the tail resistor IMHO.
http://www.classicvalve.ca/docs/CVD_CCS ... y_docs.pdf

PS, I remember reading somewhere you said to stay away from the IRFU310 cited above, why is that?

[Geek]

Hi Geek, one of your current sink/source boards could be substituted for the tail resistor IMHO.
http://www.classicvalve.ca/docs/CVD_CCS ... y_docs.pdf

Yup!

You can make the phase inverter anode resistors equal too, then.

PS, I remember reading somewhere you said to stay away from the IRFU310 cited above, why is that?

I used it simply to develop the board and it was the only MOSFET I had at the time. They are a nasty piece of work to heatsink properly. Use IRF710 or IXYS or STK equivalent.

Cheers!

[Reinaard]

The board you see is the same one as from Mable audio url : mableaudio.com they have also a chassis for it 60 dollars
I have bild that one changed the second stage same as you thit whith the Eiclone and the St70
Its working now for more than three years sound is very good I have used not the El34 in end stage but the KT77 they sound better
compleet kit was then 250 dollers

succes reinaard

[Reinaard]

The PCB is the same as from Mable audio
I have bild that one I changed the second stage same as you thith with the Eiclone and St70
I dint not use the el34 in endstage but i have used Kt77 they sound better
It is working now for more three years now whithout any compleans.
see foto

succes Reinaard

[Geek]

The board you see is the same one as from Mable audio

I used to deal with them. CAVEAT EMPTOR!