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Quick back story - I built a 6G5-A Brown era Pro for someone, debugged it with some forum help and then shipped it off. The amp was running quietly, sounded great, and was idling at around 18W per tube w/ a 451 plate voltage. The guy gets it and says everything sounds great but there's a hum. This guy is not familiar with circuits so I told him I'd spring for a local tech to look at it and find whatever may have come a little loose or whatever. So I end up talking to the tech after he had looked at it and he tells me that it sounds bad and that he compared it to the sound of a Princeton Reverb that was in his shop and says they sound different (as if they are supposed to sound the same). I press him a little for some data and he can't even tell me what the plate current was. And then he proceeds to tell me that the PT isn't right and can't handle that amp and that the whole circuit is sagging and causing low B+ and low neg bias voltage. He says it was 420v when the schematic says 450.
The PT I put in it is rated for 240mA and with 2 6L6's and 6 12ax7's should be demanding a little more than 182mA according to JJ spec sheets. Am I missing something or is this guy just grabbing at straws??
Here's the PT I used and the amp schem
http://www.classictone.net/40-18005.pdf
http://www.thevintagesound.com/ffg/s...g5-a_schem.gif
The PT I put in it is rated for 240mA and with 2 6L6's and 6 12ax7's should be demanding a little more than 182mA according to JJ spec sheets. Am I missing something or is this guy just grabbing at straws??
Here's the PT I used and the amp schem
http://www.classictone.net/40-18005.pdf
http://www.thevintagesound.com/ffg/s...g5-a_schem.gif
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