So I have 2 early Boogies I am working on , and boy has one been around the block a few times to say the least, like in the old saying " run hard and put away wet"!
Anyway they both have the same 60 HZ hum issue coming from V3 and no amount of tube swapping or trying out different tubes cured or helped the issue.
one amp is a 4 preamp tube version and the other a 5) and when you look at the preamp board filiment traces you see the the ac coming into pins 4 and 5 on V1 then goes to pin 9 on V2 and then from there on to pins 4 and 5 again on V3.
I don't know if that's the root cause of the issue( filiment wire swap) but when I ground open all the traces that run between all 3 tubes and then fed each tube by a twisted pair of wires off of V1 the hum issue was gone, in fact to the tune of a 15 Db noise floor improvement!
Early Mesa 60 HZ preamp hum
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Stevem
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Early Mesa 60 HZ preamp hum
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Not screaming like the passengers in his car!
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Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!