HELP,, new guy, new 2ch Rx build with small issue

[randalp3000]

Third rebuild on this chassis from Rj. Dr z original Prescription circuit with added single gain stage 2nd channel and slightly different power supply and cut control. Amp fired right up and sounds great, a bit brighter than my Rx's but killer. Cab I whipped up with some pine from Menards a couple months ago. Cab pic is from the last version.

On the single gain stage channel my volume on my guitar is scratchy. Could this be a leaky coupling cap? Schematic is Rx version 1 file sorry Doc.

thanks
rp

[M Fowler]

Randal,

Very cool amp congrats. Dr Z sent me his board layout for the original Prescription which was posted a year ago.

I see you shop at Menards too, LOL.

Mark

[randalp3000]

thanks Mark, I already have that file tucked away. The Rx is by far my favorite amp even over the Wreck. My only beef is the power transformers get really hot and that makes me nervous so I built my own. I became a Z dealer because I was buying so many of their amps. I have 4 original Rx's including a misspelled Preciption combo with reverb.

FYI none have a paralleled V1

[randalp3000]

I did swap out the coupling cap in the single gain stage channel and still have problems. I'm measuring -.2 Volts DC on my guitar cable from that input. I swapped out the NOS 12ay7 for a EH 12ax7 and still had about .05 volts. The other channel which shares the pre tube has no issues.

Something is leaking voltage, anyone have some ideas????

thanks much
rp

[xtian]

Do you still have trouble at .05 v? Assuming you've ruled out an actually scratchy pot...

[randalp3000]

still scratchy at .05 but less, only have a problem with this guitar with channel one of this amp.