Snakes in the Cab?

[Sprinter]

Hey folks, have a Blues Deluxe Reissue that only hisses when I plug a cable into it. No cables, no hiss... even cranked to 12 with treble cranked. Plug in a cable... hiss. Move the cable around, hiss sound changes. Plug into guitar... hiss. Put hand across strings (mutte) hiss goes WAY down. Remove hand... hiss. Playing... hard to tell, but mostly goes away.

BRAND spanking new Mogami cables (and new Planet Waves too...) all hiss.

If I put my hand on the metal of the face plate, seems to decrease quite a bit. Grounding issue? How to resolve?

Help...

[stratcat55]

Could possibly be a grounding problem. I've never had a amp completely hiss free. I just live with it unless it's seriously loud.