Noise form newish 5f4 build

[patty1969]

I have a strange problem occurring from a 5F4 I built some time ago.
I gave up on it a few years ago because it was making noises and I did not have the time to fix it.
So, having found some time, I set it up in my workshop and turned it on to warm up while I did some other electronics projects.
I remember that it would occasionally make noises when it was warm.
When it warmed up, I used a chopstick to probe around and found that the wires going from the input jacks to the first 12AX7 were microphonic. I probed the resistors and the wires between the input jack and the tube and they were all noisy when I tapped on them. ALSO, while the amp was plugged in and warming up, I had another amp plugged into the same extension cord. When I was fiddling around in the second amp, e.g., probing around, I was getting noises in the 5F4.
Are these two things related?
Any help would be appreciated.
Thanks
Pat

[shooter]

I would suspect a grounding issue, can you hear radio stations faint, they always seem to be Gospel stations when they show up!

[patty1969]

Thanks for your reply!

It seems like the shorting jacks on the bright channel were not contacting very well. I cleaned them and it seems quieter.


No radio stations. Either way, no gospel radio up here. More likely to hear a hockey game or angry talk radio (on AM I assume).


Still wondering about the noise transferring into the amp. Last night I noticed that if I turn the volume knob on the guitar, you can hear a static noise in the amp but if I touch the amp with one hand and turn the knob with the other, there is no noise. It is not a lot of noise but it is there. How normal is that?


Pat

[shooter]

try a different guitar cord, sounds like loose/broken shield on the cord/guitar.  I made the mistake of doing what you did on a 2 prong amp....I won't do that again!