SVP PRO help please

[GMSweet]

I never had a problem driving my PLX-2402 with my SVP-Pro; I did run the signal a bit differently though through some reading here and playing around.

Gain knob - Set to taste by ear, not the light. As others have said, the red light isn't really a good indicator. I like a clean sound and that light would flash 50% or more of the time.
Drive knob - Drives the 12AU7 in tube socket 4 (IIRC). This will add drive, mids and pull out some bottom end. Oh yeah, that red light will light up faster as this knob is increased; mine was always off.
EQ to taste - I always left the graphic EQ off since isn't tube driven easy to over power with gain from earlier on in the preamp.
Master - The master volume uses the tube in slot five for more gain. I find mine sounds best up after 12:00 but before 3:00 where the tube breaks up depending on the signal strength earlier in the chain.

All of that said, I built up a nice strong signal out of the preamp and used the input attenuators to control overall power into my cabs.

That first gain knob and the over all master, along with the tubes in slot 1 and slot 5 have a decent impact on the overall sound. I'm fortunate that my SVP-Pro didn't have any of the hum some others experienced.

Matt

 

[JimiLL]

I could go through a big tedious post on gain matching, actual SVP measurements I've done on my bench, extensive experience at work with DCM2000s vs. PLX 1802s and 2402s, etc. If you and/or the OP really want that, please say so. Otherwise, it's a lot of work for little reward, especially given that it's already been done in similar form so many times here on TB. Link Removed

Sure, knock yourself out. im just telling my experiences

 

[Passinwind]

Sure, knock yourself out. im just telling my experiences

OK, but before I get started, let's address this one point, please:

The problem you have is the input sensitivity on the qsc is too low for bass pre amp use. I had a 3402 that had the same problem. Shoot for 1.0v or under, I believe yours is 1.4. Your 2402 isn't getting enough signal.

If the the PLX isn't getting enough signal, in my mind that is a problem at the preamp end, by definition. Could be the hardware, could be user error. Do you agree? If not, why not?

 

[JimiLL]

I don't think so. When I ran the two different amps it wasn't a/b, but it was the same bass, same cab, same pre amp with virtually the same eq settings, same gain/output settings, unbalanced out, etc. The only thing that was different was the input sensitivity and wattage of each channel. The 700 watt amp got louder, was more clear, and it's clip light never came on, in comparison to the plx which I did see the clip light come on at one point. I also had to run the attenuateor on the plx higher than the carvin. Not scientific, but it is worth something.

The carvin obviously had a more sensitive input, but 1.7v input is rather low by any standards. Not saying another pre amp wouldn't drive it better, but that pre may be an outlier as far as output goes