Posted by Stratcat [ 70.152.40.16 ] on January 18, 2006 at 16:59:43:
Hi--This is a mid sixties two twelve combo amp. Power tubes (2) are EL34s. The schematic for this amp shows 400v at terminal A of the power cap can, 340v at B, 220v at C, and 140v at D. I'm getting 502v at A,425v at B, 289v at C, and 284v at D. I can get only get the amp to bias correctly by greatly reducing the 22K bias resistor. The power transformer runs cool, but I'm wondering if it's shorted. Would it be okay to reduce the voltage using a zener diode in this case? Thanks for any info you can give. Stratcat
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