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RE: New Tubes (6CA7)--now bias too high

Posted by xaudiomanx on February 16, 2016 at 17:32:24:
If I read you correctly you mentioned to use a larger resistor. You have to use a smaller one to let more negative voltage go to pin 5 of the EL-34's. After the bias diode the voltage them becomes negative. The orientation of the resistor is not an issue but putting the caps in properly is. You have to remember that it is negative DC voltage after the diode so the negative of the cap goes to the proper pins and the positive goes to ground.

I would also try and contact someone from DIY Tubes and see if they have a handle of why this happens. All the guys there are very smart and are great to correspond with.