How Exactly Would I Hook Up This Compressor...

Odobenus · #1 11-23-2007, 07:26 PM

in the near future i plan on getting an Ampeg SVT-3PRO and a DBX 160A compressor, assembling them into a rack, among other devices. however, i'm a bit confused on how exactly the two would be connected. here's the rear panel to each device:

Ampeg:

DBX:

...would i just put it in the effects loop? as far as i knew, gain based effects shouldn't be ran through an effects loop, but perhaps that's incorrect, or insignificant. regardless, how should it be done?

bongomania · #2 11-23-2007, 09:44 PM

You have two equally-good options. You can put it in the FX loop, or you can put it between the "preamp out" and "power amp in" jacks. If you use the FX loop, you'll probably want to make sure that loop is operating "in series", not "in parallel"- meaning either there is no blend control, or there is a blend control and you set it to 100% wet/effected. (FWIW that's just a recommendation for a starting point- some people do blend their compressed signal with the uncompressed signal, but it's not an easy starting point, or even a good idea necessarily.) The preamp out/poweramp in jacks are in series by definition, no hassle there.

Find out whether the jacks mentioned (32-35) are balanced or unbalanced, and use that info to determine which in/outputs of the dbx to use, as well as whether you'll need balanced (TRS -> XLR) or unbalanced (TS -> TS) cables.

As far as "gain based effects" not being used in the loop, that's hogwash. Just maintain "unity gain", where the output is the same peak level as the input. Or if you like, you can even use gain effects to drive the power amp section of the amp, which can sound cool (even awesome) depending on the amp.

Check out the compressor FAQ linked in my sig for more info.

Odobenus · #3 11-24-2007, 10:58 AM

hey thanks a lot. well, i suppose if i have both of those options i'll try each of them out and see what i like.

(great links by the way, in your sig.)

agreatheight · #4 11-24-2007, 11:17 AM

Quote:

Originally Posted by bongomania

As far as "gain based effects" not being used in the loop, that's hogwash.

I'll politely disagree with this - many gain based effects (especially distortion) sound much different in the effects loop than they do run before the amp. Sometimes different can be fine, sometimes it can be bad. Compression... well, my inclination would be to run the comp before the amps input, but you can certainly try all options (and you probably should) to see what sounds best to you.

Good luck!

bongomania · #5 11-24-2007, 11:50 AM

But see, we aren't actually disagreeing- I was saying there is no reason to believe that gain-based effects (in general, as a rule) shouldn't be used in an fx loop, not that there is no possible difference in the sound. You need to take into account the signal level and impedance of each device. Not all fx loops have the same in/output impedance or optimal signal level, and not all "gain based effects" do either.