Marshall Jubilee

[Spencer Landry]

I am having a scratchy sound when I plug into the amp. I don’t know if it’s the jack or something else.Can anyone give me some opinions?

[nickb]

If your rotate the input plug do you still get scratchy noises? If so then a squirt of contact cleaner into the socket will likely work wonders.

[The Dude]

Welcome to the place!

That could be any number of things. Is the scratchy sound there just when you plug in, or does it continue after you've plugged in? Does the sound change in any way with the volume control or any other controls? Check solder on input jack(s). Do any pots make noise through their rotation? If so, clean them.

[J M Fahey]

*Some* leaky/gassy tubes pass too much current through the grid (we are talking less than 1 uA here) ,that current passes backwards into the guitar pot and any DC through a moving pot makes it scratchy.

MY point being if after socket, jack and guitar pots you still have scratch left, try other tubes at the amp input.

But clean first.