Plush P1000s on the bench

[Danglin' Fury]

Hey all. I currently have a Plush P1000S on the bench. I cant find a schematic anywhere but some folks say it is an almost 100% copy of a Fender Twin. Other folks say it is a copy of a Dual Showman. Any truth to this? It has all "original" tubes. By that I mean old RCA 6L6's and a bevy of old 12AX7's and 12AT7's. Not having a schematic sucks but what sucks even more is, when I turn the damn thing on and kick it off standby, all I am rewarded with is a VERY loud "farting/buzzing" noise. This also happens after I replaced all the 6L6's with new JJ's. Does anybody know which Fender schemmie I should follow or maybe does anybody have the actual Plush schematic? I am about to just tell the guy this amp is a turd as he told me a buddy of his just gave it to him. It looks as if somebody has already been inside the amp as the electrolytics in the power supply have been changed. It has a fairly new looking "multi-cap" can attached to the outside of the chassis. I say fairly new looking as it does not have the dust and cobwebs the rest of the outside has. Could the OT be shot? This is not my first vintage amp to repair but I have never even heard of Plush amps til I got ahold of this one. Thanks for looking.

-Shawn-

[Fragger]

This guy swears it`s a direct copy of a Fender Twin Reverb. Plush Guitar Amplifier Restoration - YouTube

[Enzo]

At this point I would probably not even be looking at a schematic.The thing resembles a Fender? Fair enough, power amps are pretty much the same all over, mainly different phase inverters, but every push pull amp has one of those too. Pick a Twin Reverb, it will be close enough. If one schematic says 220k grid resistors, and the amp has 330k grid resistors, that won;t be the cause of loud noises. I'd be looking at the B+ for excess ripple (failed filter cap or shorted rectifier), I'd look at the bias supply for loss of filter as well. On anything fender, the B+ will be on pin 3 of the power tube sockets, and bias will be on pin 5.

The phase inverter tube is going to be the one next to the power tubes, does pulling it stop the noise? Does the noise remain if you pull all the power tubes?

[Leo_Gnardo]

Hey all. I currently have a Plush P1000S on the bench. I cant find a schematic anywhere but some folks say it is an almost 100% copy of a Fender Twin. Other folks say it is a copy of a Dual Showman. Any truth to this? It has all "original" tubes. By that I mean old RCA 6L6's and a bevy of old 12AX7's and 12AT7's. Not having a schematic sucks but what sucks even more is, when I turn the damn thing on and kick it off standby, all I am rewarded with is a VERY loud "farting/buzzing" noise. This also happens after I replaced all the 6L6's with new JJ's.

What Enzo says. Here's some more.

Twin Reverb = Dual Showman Reverb and your Plush is a sloppily built but otherwise copy of the Fender. I think the hi voltage power supply may be a bridge instead of Fender's typical full wave rectifier. Big buzz could be a number of things, from failed bias supply, shorted hi voltage rectifiers, to shorted output transformer & more besides. Standard troubleshooting techniques will help you get it running. I hope you have a Variac. First I'd check both transformers for shorts or dodgy readings, also check rectifiers, then if they seem good, inspect & correct power supply circuits first. Then with no tubes in it I'd bring it up slowly from zero and monitor supply voltages. That's a start. Don't wreck your new JJ's, use "pull" (used known good) output tubes until you're sure the amp is behaving.