Fixed the BAd socket issue on my 68 Super Reverb AB763. NOw, when I hit the amp at moderate volume with a coule hard chords and immediately mute the strings, I hear the amp still going a few seconds. It is a strange tone, not very loud but shouldn't be there,,,
Is this a known thing ? what is it ?
amp plays alone !
Moderators: pompeiisneaks, Colossal
Re: amp plays alone !
oscillation?
Re: amp plays alone !
I guess it's a sort of "ringning" that goes on after i stop playing. Not always, not always for the same time...
Is that oscillation ? how do I fix it ?
Is that oscillation ? how do I fix it ?
Re: amp plays alone !
Microphonic tube? Try lightly tapping on tubes with a pencil. See if you get "ringing"
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Stevem
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Re: amp plays alone !
On both channels is it doing this?
If so then the issue lies likely from the PI section down stream to the speaker output jack.
Here’s a important suggestion for the next time you you go thru a rebuilt of any amp in the way you did this one.
First if it’s not smoking or blowing fuses play and note down any thing strange that it should not be doing.
Next when your in the rebuilding phase play the amp after every part you change out, that way if something goes off the rails you do not have to take more then one step back to look thru what you did.
To this very day 48 later I still do this and a test any resistor or cap to confirm it’s value is correct.
Seeing as you just replace a tube socket a guess on my part would be that you now have a grid wire too close to a plate wire.
I have also had over the years a few bad preamp tubes that would ring after a note I played had stopped .
It did this at the pitch of the note I played with a distorted fuzz type sound.
Maybe this is what your hearing ?
If so then the issue lies likely from the PI section down stream to the speaker output jack.
Here’s a important suggestion for the next time you you go thru a rebuilt of any amp in the way you did this one.
First if it’s not smoking or blowing fuses play and note down any thing strange that it should not be doing.
Next when your in the rebuilding phase play the amp after every part you change out, that way if something goes off the rails you do not have to take more then one step back to look thru what you did.
To this very day 48 later I still do this and a test any resistor or cap to confirm it’s value is correct.
Seeing as you just replace a tube socket a guess on my part would be that you now have a grid wire too close to a plate wire.
I have also had over the years a few bad preamp tubes that would ring after a note I played had stopped .
It did this at the pitch of the note I played with a distorted fuzz type sound.
Maybe this is what your hearing ?
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!
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!