New trainwreck build noise issues

[audiosalvage]

This is a new Express clone which works but horrific thundering noise from the vol and treble pots when turned. HELP

[bepone]

not enough input data to help layout, pics, heater groundings?

[audiosalvage]

I pretty much followed the ceriatone layout. The amp has a slight hiss but I've all but eliminated hum by using an artificial heater CT. I'll post some pics

[bepone]

remove all the wires from PI and output section and concentrate more, and rewire again, v3 tube wiring can be better , looks scrambled
+ grid wires to the output twist between them and put it under the board, close to chassis not on the air
gnd for the first section (minus terminal from the capacitor supplying the first stage ) connect close to the input jack, not there where are others,
and then we will see if something is better

[audiosalvage]

Well I followed your instrutions with no change. Still rumbles loudly with a slight turn of the vol or treble pots.

[wpaulvogel]

Those black mica caps are known to be leaky and prone to failure. I had several go south and stopped using them. I now use the brown or tan CDE 1000 volt for current production mica caps and prefer the vintage Lemco, Radiospares or SRC.

[bepone]

Well I followed your instrutions with no change. Still rumbles loudly with a slight turn of the vol or treble pots.

ok then you can try to reconstruct / resolder all the grid wires and resistances/stoppers to the grids in first two tubes, maybe is bad solder only or bad resistor connection..

[neskor]

check also output transformer primary
maybe you reversed OT primaries
check this active topic:
http://ampgarage.com/forum/viewtopic.php?f=6&t=34851

[ChopSauce]

Those black mica caps are known to be leaky and prone to failure. I had several go south and stopped using them. I now use the brown or tan CDE 1000 volt for current production mica caps and prefer the vintage Lemco, Radiospares or SRC.

Ok for the no name black silver mica caps but even the CD branded ones?

[audiosalvage]

I reversed the OT primary with no change. mind you that this pot behaves like an old scratchy one but very loud

[audiosalvage]

the amp does not squeal and humming is very minimal. Moving the pot even a little produces a thunder crash

[audiosalvage]

just measured 24vdc on vol pot

[ChopSauce]

Leaky siver mica cap?

[audiosalvage]

which one?

[ChopSauce]

What did you used for C2: a no name cap or a "CD_" branded one?