Fender repair question - buzzing.

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Fender repair question - buzzing.

Postby blackflag2 on Sun May 11, 2014 10:37 pm

So I have an '83 Fender Concert. It hasn't been worked on very much, no big maintenance or anything. I was playing it the other day, and it was fine. Then I lugged into someone's cabinet - and I think the cabinet was wired wrong. I think it was running 16 ohms instead of 8. It sounded odd, and my amp started struggling - sounding like the tubes were giving up. So I quickly turned it off and went back to the original speaker...then I had a buzz. It doesn't depend on the volume, and doesn't change if I touch anything. If I turn my guitar all the way down, the buzz is still there. I can make it reduce slightly if I turn the treble all the way down. I put in a new set of tubes, and everything sounded better - but the buzz is still there.

Does anybody have a good idea what happened here and what to repair?
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Re: Fender repair question - buzzing.

Postby blackflag2 on Sun May 18, 2014 8:30 pm

Come on people - we need to brainstorm this!
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Re: Fender repair question - buzzing.

Postby Unit_1 on Mon May 19, 2014 2:31 am

this place can be pretty dead on the weekends

bbq's and gigs and all

when checking for amp induced noise you should always check it without a guitar attached

do that and see if it still makes the sound (this is just trouble shooting step A)...
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Re: Fender repair question - buzzing.

Postby blackflag2 on Tue May 20, 2014 3:27 am

Yes, I should have said that - the noise is the same with no instrument attached. It does change with the amp volume, but not with an instrument.
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Re: Fender repair question - buzzing.

Postby pdf64 on Tue May 20, 2014 7:12 am

Does it buzz if operated without a tube in the V1 socket?
What are the plate dissipations of the output tubes?
Describe the effect of turning the hum balance control from one end to the other (maybe the track is blown and the heaters have lost ground reference).
Is there continuity between the chassis ground and the line plug ground terminal?
Is the line ground good?
Schematic http://schems.com/manu/fender/concert_ii_83.pdf
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