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Hi everyone! I would like to ask for your help.
I have a Fender Bassman SP3100 Solid State amp which I use with a passive MM copy bass.
However not so long ago it started to work funny, (I have bought this new bass, which has a fairly bigger signal, than the previous JB type, not that great however to blow the amp) and from week to week it becomes worse. Here's what it does:
If I play on the bass (volume max, passive pickup) but more notably when I turn my Woolly Mammoth clone on (same volume as the dry signal) it starts to moan under my bass sound. Like 5 notes (or an octave and 5 notes) below the original sound. Not if I turn the bass' volume pot down, however it have never done this before... Even with loud signal it was OK. What do you think, what can be the problem?
And it does this more and more often...
Also sometimes I tried to use it with a looper pedal (bass->Loop Station->Bassman) and played a bass riff, then loop it and play a bass solo on top of it. But most of the time the whole thing ended up in the drop of the volume level (it became some half the volume than it was before.) So I thought it's not healthy and stopped doing that. But maybe this info can be helpful.
The transistors are two 2n3055-s and I think they have to do something with it, but I don't know.
Also the previous owner used it as an organ amp and made a few modifications on it. I think the preamp stage is still in its original condition, however I have to take a closer look at it. It worked well for a long time, even with bass.
I saw in another thread that you said that the output transistors could be changed to MJ15024 or MJ15003 What would change if I would replace them? (It's actually a different question, regardless of what the real problem is. )
Sorry for the loads of questions!
I have a Fender Bassman SP3100 Solid State amp which I use with a passive MM copy bass.
However not so long ago it started to work funny, (I have bought this new bass, which has a fairly bigger signal, than the previous JB type, not that great however to blow the amp) and from week to week it becomes worse. Here's what it does:
If I play on the bass (volume max, passive pickup) but more notably when I turn my Woolly Mammoth clone on (same volume as the dry signal) it starts to moan under my bass sound. Like 5 notes (or an octave and 5 notes) below the original sound. Not if I turn the bass' volume pot down, however it have never done this before... Even with loud signal it was OK. What do you think, what can be the problem?
And it does this more and more often...
Also sometimes I tried to use it with a looper pedal (bass->Loop Station->Bassman) and played a bass riff, then loop it and play a bass solo on top of it. But most of the time the whole thing ended up in the drop of the volume level (it became some half the volume than it was before.) So I thought it's not healthy and stopped doing that. But maybe this info can be helpful.
The transistors are two 2n3055-s and I think they have to do something with it, but I don't know.
Also the previous owner used it as an organ amp and made a few modifications on it. I think the preamp stage is still in its original condition, however I have to take a closer look at it. It worked well for a long time, even with bass.
I saw in another thread that you said that the output transistors could be changed to MJ15024 or MJ15003 What would change if I would replace them? (It's actually a different question, regardless of what the real problem is. )
Sorry for the loads of questions!
) although I don't know whether they are the originals, or not. They look like originals. Two huge aluminium cans with "General Electric" and 072454 written on them. And some other numbers.
) sound of the amp?
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