Pepco help!

[Gordo7189]

Hi All, new here and while I have tried the search options I can't find exactly what I need. I am putting an isolation tranny on an old Trend amp (Pepco) and after following an internet schematic, I have considerable hum. Several other sites talk about how to fix it but only written instructions, no drawing. Has anyone confirmed a good working schematic for these amps? It is a Pepco 201 chassis, 12ax7, 50l6 and 35z5 for tubes. Many thanks,

Gordo7189

[g1]

Can you post the schematic you used, and the links to the written instructions?

[Gordo7189]

Pepco

Can you post the schematic you used, and the links to the written instructions?

Pepco 201 Amplifier Mod this is the article that has the schematic. I followed this, fairly well I feel and now have a loud hum that increases with the volume. Amp works though.

http://music-electronics-forum.com/t34429/ this is an article that points out faults but I do not feel confident to proceed without a drawing. Also I read about the "death cap" but don't know where it is on the board and don't know what to do with it.

Thanks!

[Gordo7189]

Does this help?

Gordo

[g1]

Ok, I saw the comments loudthud made in this post: http://music-electronics-forum.com/t34429/#post320071
I'm not sure what he meant about the deathcap and grounding connections.
I would suggest you try moving the heater connections to the other side of the bridge, like he mentioned. (12ax7 end of heater string to bridge pin4, resistor end of heater string to bridge pin3)

[Gordo7189]

Ok, I saw the comments loudthud made in this post: http://music-electronics-forum.com/t34429/#post320071
I'm not sure what he meant about the deathcap and grounding connections.
I would suggest you try moving the heater connections to the other side of the bridge, like he mentioned. (12ax7 end of heater string to bridge pin4, resistor end of heater string to bridge pin3)

I made this change and still have the hum! No difference!


Gordo