Silly preamp/power amp set up question

NickfromSOS · #1 06-22-2011, 07:16 AM

I'm new to a preamp/power amp set up. I've always used heads prior. When running my set up (BBB Bmax into a Crown XLS 1000 bridged at 700 watts at 8 ohms into a markbass traveler 15 cab) what do you use to control the overall volume? I set my preamp gain knob so the my loudest notes are just barely setting off the built in compressor. Then what? Do I set the power amp to full power and use the master out of my preamp to control the level? Do I run the preamp master all the way up and use the volume knob on the power amp to control things? Do I use a mix of both? If so, what would I turn up to get a little volume boost if needed mid show?

NKBassman · #2 06-22-2011, 07:19 AM

Quote:

Originally Posted by NickfromSOS

Do I set the power amp to full power and use the master out of my preamp to control the level?

That's what I always did. I don't think there's anything wrong with doing it that way, but I could be wrong.

Bass_Pounder · #3 06-22-2011, 08:12 AM

For the best signal to noise ratio, I always set up my gain staging so that my hardest notes were just flickering the power amps clip lights.

Once the pre was set, it was not touched again.

I adjusted for volume using the power amps attenuators.

beans-on-toast · #4 06-22-2011, 08:32 AM

Using a combination of the pre and power gain settings is fine. It allows you set a hotter gritty signal to the power amp if you want distortion. If you set the pre on full you might be way overdriving the power amp input and causing a lot of distortion. For clean settings, I find that it is best to set the power amp on full and use the pre to control the overall volume.

Don't let the led clipping lamps rule what your settings should be. Use them as a guide and let your ears help you to determine what the best settings are. If it sounds good with the lamp on most of the time, then use it that way. You won't hurt the amp. These LED's are calibrated differently from one piece of gear to the next.

NickfromSOS · #5 06-22-2011, 09:00 AM

I should have mentioned that I want a clean tone.. no distortion

dhomer · #6 06-22-2011, 10:28 AM

I use a BMAX too w/a DCM 600. The amps are always on full. Gain is set up so that its clean, volume is adjusted on the preamp master Can't remember right off how the tone stack is set, 2-0-? Paramids centered about 900, boosted 5.. Excellent tone..

chucko58 · #7 06-22-2011, 11:49 AM

Here's what I do, your mileage may vary.

I hook everything up BUT don't connect one side of the power amp to a speaker. I turn the gain on that side of the power amp all the way up. Then I set the preamp gain (or master, depending on the preamp) so that the power amp clip lights just barely come on when I really bang on the bass.

I only have to do this once. I never touch the preamp gain or master again.

At practice or the gig, I use the power amp gain to control volume.

This leaves me with maximum headroom under all conditions. I can turn up the power amp as much as I like and not clip it when playing normally.