diy dual rec problem

[Thomasdj]

Hi!

I am building the 3ch dual rectifier and I am almost finished...I think!

Well..i have made a few modifications to the schematic..I added individual bias pots to each power tube.

I 've got two problems.

I got signal through each channel and so I assume that the preamps are working properly. However I've got a nasty high freqency sound coming out of the speaker. Another problem is that I only get low power even when turned at high gain and master.

I run the amp with 4xEL34 so i adjusted the bias negativ voltage to ca. -40v at each power tube at Grid 1 (pin 5). But when measuring cahtode voltage across 1 ohm inserted cathode resistor I only measure 10-12 mV!!! ..what is wrong with my circuit??

Is it the 4x220K that should be lower??


Schematic
http://music-electronics-forum.com/attachment.php?attachmentid=1400&d=1198093749

Bias schematic
http://music-electronics-forum.com/attachment.php?attachmentid=1399&d=1198093726

Thanks

Thomas

 

[msi]

First of all, no one can see your schematics unless they register on that forum. That's something I'm not going to do, so if you want to get your answer here, I suggest you figure a way people can see it without having to register. Secondly, this really isn't a website for DIY amp building. You might try http://sloclone.yesterdaysrevolt.com/ That forum is dedicated to building hi-gain amps like I assume (if I could see the schematic) yours is.