Just like a lot of amps, mine hisses.
The interesting thing I've found, however, is that mine only hisses when I'm not touching a metallic part of my axe; nobs, strings, tuning heads, bridge or even the plug from my lead when in contact with skin will reduce hissing to negligible amounts - break contact and it fires up again.
The only thing I can come up with is some form of earthing problem; I recently (like, three days ago) took my guitar fully apart, covered it in Gaffa tape and resembled it. I made certain that the earth wire from the electronics was in contact with the bridge.
Any ideas on how to eliminate this?
The hiss is so directly controlled by metal-to-skin contact that I can actually do Morse code with it.. :/
What is gaffe tape?

If you line the control cavity and pickup cavities with conductive copper tape and ground them it will eliminate it.
Quote by DeathByDestroyr
See, it's important that people clarify when they say "metal", because I pretty much always assume they are a Cannibal Corpse fanboi.