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Hi i've been using a plexi kit for about 8 months with no problems.
It's got a vvr in it but when i tried to crank it up i got alot of squeal or hum
Also my b+ is only reading 250v now.
The squeal might be a hum issie but i'm not sure as it comes even when the volume is quite low.
I've shortened some wires, resoldered everything and moved all the wires but that hasn't helped.
Really do need some help please.

Did you get a VVR or our VRM. The VVR is dropping excessive voltage. I would recheck the few components and get it working properly first.

Our VRM only dops a few volts B+ when on max. That's the benchmark IMO. I have seen VVR drop 30 volts, but not as much as your does.

When you take the VVR our of the circuit, does the amp return to normal?

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Hi,
I've got my voltage back now, just spent a day redoing some wiring.
I need help with a squeal/hum issue.
With volume on full when i turn the gain up there is a hum present would that turn into squeal sort of feedback sound.I don't know where the hum is coming from.
I get it in both channels worse with boost on.
Volume on full, vrm on full and gain could be as low as 4 or 5 before i get a squeal feedback sound.
I've redone every ground point, shortened all ac lines resoldered all jack sockets and gone over the shielded cable.I swapped blue and brown wires on power tubes but nothing has helped it. i even moved the 68k resistors nearer the pin at v1, still nothing.
Other than that i love this amp.

Do you get the hum with no guitar plugged in? Same question for the squeal. You get the squeal thing on both channels, or just the TMB channel? What happens to hum or squeal when you remove V1? Then what happens when you remove V2? Finally V3. That should give some clues to where these problems are getting into the amp. If you can post some clear photos, others may be able to spot something you might have missed.

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Great tones come in small glass jars!

Is this a head or combo? I had problems with a squeal with my head. It only happened when I had it on top of the speaker cabinet. Turns out it was a microphonic tube. Tap on the 12ax7's . Especially V-1. If you hear the taps you can try swapping it into a position further down the line (V-2, V-3 )
What size zener did you use? I was dropping too many volts with a 6 volt. After changing to a 12 volt , I only dropped a few.
The hum went away for the most part , also.
The rest of the hum left when I did the hum fix:SCRATCHY POT LAYOUT - VRM INPUT MOD
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Good Luck with it!

LeeMo