Hissing or humming? It's normal for a high powered amp to have some hiss. Hum is a different story. Single coil pickups? As far as humidity is concerned I think with electronics, the drier the better.

hi hueseph

No this isn't the regular hiss you can expect from a tube amp, it's way to high and sibylant, it's a continue SSSHHH.... like there was a ton of reverb turned on when there is none.
Sometimes it became a real feedback.

This happens in all the rooms served from the same electricity line.
I tested the amp at home and it works perfectly.

Yes the Fender Jazzmaster I'm using has 2 singlecoils, but this isn't a guitar issue, since I'm having the same problem with the bass on a different amp.

hiss/hum

any thoughts on power conditioners?

Have you tried taking your amp and guitar to someone else's house to see if you have the same problem there? If the same thing happens (hiss) at someone else's house you'd have to take a closer look at the guitar/amp/cable/batteries.

If you are playing close to a computer monitor you will get a noise - if you turn your guitar in certain directions the noise will get better or worse.

I also found that you can try to ground your guitar by wearing a wire around your wrist with the other end fastened to the bridge of the guitar - just to determine if it is a grounding problem - but a grounding problem isn't usually a hiss.

good luck,

ceb

Yes I tested amps and guitars at home (another house) and they works fine.
Now I will try a "filtering device" on the electicity line. The electrician friend should provide one in few days.
Let's see what's happen....