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Post by Runewalker on May 28, 2005 16:53:48 GMT -5
Just replaced the old tired preamp set in my '72 Super 6 (Fender Twin Brain, 6 10s). Sound is better but a new and here-to-fore not there HUM emanates from the amp. It is like a 60 cycle hum, not there on standby. Increases in volume as the Master is turned up, and is there even if Norm or Virbrato channels are turned to '0."
This amp has been a solid, reliable performer for years. First time I ever heard this sound.
Could the new preamp tubes cause this? or is it in the power amp stage. Perhaps the transformer?
Help!
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Post by Trey on May 28, 2005 21:04:06 GMT -5
Sounds like one of the preamp tubes you put in there may be bad. Give each of the tubes a light tap with the eraser end of a pencil and see if any of them squeal or make any noise at all, if they do it's a bad tube. If everythign was working fine before you put the tubes in, I would think that would be the most likey place for the problem to originate from...
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Post by Runewalker on May 29, 2005 0:24:15 GMT -5
Will give that a shot. Thanks Trey.
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Post by Runewalker on May 30, 2005 0:14:31 GMT -5
Tried your method T, and notices a strange noise on the AT7 in the reverb slot.
Pulled it and saw that one of the pins was bent - not making a complete coupling.
straighten the pin, and the noise is gone.
thanks Trey
RW
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Post by Trey on May 30, 2005 7:28:59 GMT -5
Tried your method T, and notices a strange noise on the AT7 in the reverb slot. Pulled it and saw that one of the pins was bent - not making a complete coupling. straighten the pin, and the noise is gone. thanks Trey RW No problem, glad that solved your problem. Always suspect the tubes first when your having a problem with your amp, 9 times outta 10 they're causing the problem. |
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Post by StratLover on Jun 1, 2005 15:13:04 GMT -5
Nice one "Trey", thats the quickest fix to date.---  --- |
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Post by UnklMickey on Jul 15, 2005 11:09:49 GMT -5
As usual Trey had some good advice.
He got to the problem, but only half the lesson was learned here!
Always suspect any changes you have made between when things were O.K., and now when they aren't.
THEN suspect the tubes.
In this case they were the same thing.
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