Is there supposed to be a hiss from a tube amp without anything plugged in?

Question

I think one of my tubes might be blown, im not sure. I have yet to test it out again, i opened it up and checked the large glass tubes, and i noticed that the prongs werent pushed in all the way on both of them so maybe that was the problem. I tried turning it on and there is a fairly audible hiss coming from the speakers, is this normal for a tube amp? its a peavey 5150 combo

Answer 1

The key is if you plug your guitar in and compare how loud the hiss is compared to how loud your guitar is.  You may have the volume controls cranked up to get the hiss.  Every amp will have some hiss with no input if you turn the volume WAY up.

If the volume is not way up and you are getting hiss, you may need new tubes or maybe take it in for service.

Answer 2

A good amp should not produce any noise/sound without any input.