Thank you, sir. Much appreciated. Would phantom power clean up the voltage across the input?

Can't you just put a noise gate on it? Shit, my rig makes plenty of background noise, but it's so minute of a level as compared to the rest of the signal that you really can't notice it except while I'm playing - only when I stop.

Preamp tubes shouldnt get ridiculously hot.

Some heads dont have the cleanest direct out, period.

Also- the "high boost" and "bright" buttons on the SVT-4 amplify hissy noise like crazy.

Why not work with a few signals- DI from the bass, DI from the head, maybe a mic and blend them.

All good points.

I run an SVP pro preamp, with 5 12AX7s. Thunda is right, I can't use the bright button or I get all kinds of noise. Typically it's around the 12-15k range that I'm not using anyway, so I just put a lowpass filter on it.

Direct out of this preamp is awefully nice and super clean, but a little too intimate for my tastes. I always like running a little cab with it for ambience, but again more noise introduced. I let it warm up for at least one half hour before tracking so it warms up.

MC hit right on with the tubes. If they're "pingy" or microphonic they're just dying and need replacement. You'll lose signal and pick up distortion along the way. As stated before the brand of tubes also plays a big part.

Your bass itself could also be the problem. Are your pickups active? Changed the battery lately? How does the bass sound plugged straight into the board? If the amp has to compensate heavily for the EQ shaping that your bass doesn't have on it's own, any amp will start to pick up noise.

Yeah, we changed out Aaron's battery first thing, and then DI'd it straight to the board and we got a clean signal. I don't know if Aaron's got his bright switch engaged, but I will certainly investigate this afternoon. The hiss is definitely coming off the pre, but it started well into the session, AFTER we had already been tracking for a while. Which vexes me thus. Thunda, you should hear the bass tone we've achieved.

Mike,
My bass player has ann SVT-4 as well, I noticed there are two direct outs on the back, one wet and one dry. You could try switching from whichever one you're using to see if thats the problem. Also the direct out has a level control on the front of the amp too, could be a bad pot??? I dunno, just some suggestions. Also, look at the tubes, if one or more of them have a blue tint to them then they could be on there way out.

B