J
Joe-TX
Active member
I picked up this '79 JMP 2203 that's been modded off of Craigslist the other day and I got a pretty good deal (at least I think). It sounds great except for a low hum that's constant and a few scratchy pots. The amp has been majorly neglected but it works and sounds fantastic (except for the hum) and I plan on getting her cleaned and gone over by a competent tech.
The seller was the original owner and gave me a bit of info but he left out a few details, he never mentioned the push/pull vol and gain pots. I did get the modder's info and I am trying to get in ouch with him but no luck yet. The mods were done in '95.
Here is what I do know about the mods.
There is an extra 12AX7 and a loop was added. The presence control is the 2nd gain level, the master and gain pots are push/pull.
I only really hear a difference when I pull the master vol and it seems to be more of a mid shift than anything else. I don't hear any changes when the gain is pulled out.
Can anybody tell much about the mods by looking at this? TIA
The first pic is out of focus so I took a couple of close ups.
The seller was the original owner and gave me a bit of info but he left out a few details, he never mentioned the push/pull vol and gain pots. I did get the modder's info and I am trying to get in ouch with him but no luck yet. The mods were done in '95.
Here is what I do know about the mods.
There is an extra 12AX7 and a loop was added. The presence control is the 2nd gain level, the master and gain pots are push/pull.
I only really hear a difference when I pull the master vol and it seems to be more of a mid shift than anything else. I don't hear any changes when the gain is pulled out.
Can anybody tell much about the mods by looking at this? TIA
The first pic is out of focus so I took a couple of close ups.
