Minneapolis help needed

Marshall Amp Discussion

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sonofmickel
Posts: 162
Joined: Sun Jan 13, 2008 4:56 pm

Minneapolis help needed

Post by sonofmickel »

I can offer pizza beer whatever...
Having atone control problem that needs to be found out.
This is too stupid to be a problem. The treble control acts like a gain control. It defies all reasoning. Have rebuilt the entire circuit, subbed known good parts, bypassed, etc... It has got to be something only I could do...

St Paul, Minneapolis.
Stevem
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Joined: Fri Jan 24, 2014 3:01 pm
Location: 1/3rd the way out one of the arms of the Milkyway.

Re: Minneapolis help needed

Post by Stevem »

Still issues going on ? Oh man!

Could you post a picture that will show how far away the tube sockets are from the controls?

In the mean time try this and see if it makes any improvement.

Take a length of wire that will be long enough to let you solder it to a gain stages plate and then rap it 3 to 4 times around that gain stages grid wire and be sure to insulate that bare end.
If you are having a issue with oscillation taking place this will kill it and or tame it enough to let you pin down what stages are involved, if this is taking place you have a layout issue with the amp going on!

Thanks for the dinner offer, but its too far from NY ! LOL
When I die, I want to go like my Grandfather did, peacefully in his sleep.
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!
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M Fowler
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Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: Minneapolis help needed

Post by M Fowler »

I'll send you a contact in the Twin Cities. PM'd you.
sonofmickel
Posts: 162
Joined: Sun Jan 13, 2008 4:56 pm

Re: Minneapolis help needed

Post by sonofmickel »

Thanks for the contact. Very nice offer to hang out and go over the circuit.

The problem was a 25kL volume pot that changed the response curve of the tone stack. 25kL bad, 500k/1M good!
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M Fowler
Posts: 14036
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: Minneapolis help needed

Post by M Fowler »

Great news and he knows his amps & pedals. :)
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