ampage Tube Amps / Music Electronics	For current discussions, please visit Music Electronics Forum.

ampage archive

Vintage threads from the first ten years

previous: Bruce Troy, did you put the 135ohm resist... -- 2/24/2000 6:12 PM

Re: Blackface BandMaster..Master Volume?

2/24/2000 9:06 PM
Troy	Re: Blackface BandMaster..Master Volume? Bruce: I initially put the 2-130ohm 5W resistors on the AC lines going into the rectifiers and this worked fine until one of the resistors opened up on me (may have been a fluke since I calculated about 2W across each resistor at idle; can't remember the voltage drop). I then pulled the resistors and put 2-5W-12V zeners in series from the PT CT to ground. This has worked so far with about 424Vdc on the 6V6's plates (415Vdc on the screens). I haven't measured while cranked; I've been trying to chase a hum that I believe to be in the PS (still hums when PI tube is pulled). Troy

2/24/2000 9:06 PM

Troy

Re: Blackface BandMaster..Master Volume?

Bruce: I initially put the 2-130ohm 5W resistors on the AC lines going into the rectifiers and this worked fine until one of the resistors opened up on me (may have been a fluke since I calculated about 2W across each resistor at idle; can't remember the voltage drop). I then pulled the resistors and put 2-5W-12V zeners in series from the PT CT to ground. This has worked so far with about 424Vdc on the 6V6's plates (415Vdc on the screens). I haven't measured while cranked; I've been trying to chase a hum that I believe to be in the PS (still hums when PI tube is pulled).

Troy