Is this normal?

[darkarbiter7]

Hey,

Just a question about my Chicago Blues Box Roadhouse.
I noticed that it has more of a "waterfall" sound in the background instead of a standard humming noise when it's turned up.
Like, it produces less noise than my Peavey Classic when turned all the way up, but the noise is kind of strange, really like a waterfall is going on in the background.
Is this normal, or should I have my tech check it out?

Much thanks!

[mike80]

Sounds like you're describing what's called "white noise". Usually found on high gain amps.

It's a possibility that one of the preamp tubes is noisy. Try swapping the tubes out with some others and see if that takes care of it.

[darkarbiter7]

Alright. It's a rather low gain amp though.
I'll check the preamp tubes.
Do you know which one (which slot), it'd most likely be?
I'll check all of them, but I want to know where to start.

[darkarbiter7]

Sorry for the double post...

It was the V1 preamp tube. Which is too bad, because it was a nice RCA 12AX7. :(
I got it from tubedepot's 15 buck deal, so I didn't lose much.
Actually, I had a spare RCA to throw in V1 and I put the tube which was giving me problems in my tremolo slot.
Sounds real nice. Smooth and subtle, and it doesn't give off any noise there, it's a big improvement over the JJ I had in there :).

Anyways, thanks for the help!

[mike80]

Great! :D

Tubes should be the first thing you check when you run into noise problems. 9 times out of 10 the problems with a tube amp are caused by the tubes. Always keep a spare set of preamp and power tubes laying around to swap out.