help with Danelectro "airline" amp sizzling/crackling noises

[SliperySlidey]

Hello Everyone

I was having a bit of trouble with an old danelectro "airline" amp that I have... its starting to
make some pretty annoying crackling/sizzling noise... and am trying to troubleshoot, and was
looking for some suggestions:

here is the tube compliment:

6x5 rectifier
2 6v6 push pull
2 6au6

So far I have cleaned all the tube sockets with contact cleaner, but still have the noise.

All tubes check out fine.

When I pull the preamp tubes (either one) the noise goes away... so I am thinking its
somewhere in the preamp. I have never owned an amp w/ 6au6 preamp tubes so Im not
sure where the plate load resistors are, I was told that those could be the culprit. If anyone
could point out where the plate load resistors are in the preamp stage I would appreciate it,
or any other suggestions what might the culprit be.

please see the attached schematic

airline-gdr-8513a-amplifier-schematic.pdf

thanks everyone,

smitty

[jmaf]

That means the problem is at or near V1. You've nailed it yourself I guess: likely suspects are R10 or the tube itself. Do you have a known good tube to replace it with? Tap R10 and R13 with a dry chopstick, other solders near V1 may be worth tapping just in case. As for your question, the only two plate resistors there are R10 or R13.

[SliperySlidey]

Thanks for the input! Yes, I have replaced V1 with different tubes... I have a Mullard in there now (great tube, non-microphonic)
So I will start poking around V1 with a chopstick as you suggested ...

thanks again, I will post my findings.

smitty