Another compression question (re: output)

[John Stephen]

I've started a new thread for this question, because the other compression threads are getting pretty darn long. I appreciate everyone's willingness to jump in and offer advice, as I am still very new to compression and still learning.

I am using a borrowed MXR M87 compressor, with my Epiphone Rumblekat short-scale bass and a Fender Rumble 40 amp.

I find that I can turn off the amplifier gain completely, as in zero, and still play through the amp, using the output from the MXR M87 compressor (there's a knob to control the output level). My question is, how much compressor output to use and how much amplifier gain to use -- the relationship between the two (if there is one). Wondering about any insights into this.

 

[BeauZooka]

My suggestion is start with matching what the output volume of the bass is with the compressor off, since this around what bass amps are used to seeing.
After you get used to it you can experiment with louder or quieter to see how your amp reacts and how you like the sound. Some like to hit the amp with a hot signal to get overdrive or more compression. Some amps sound like crap when you do this, or you may not want any overdrive at all.

 

[John Stephen]

Thanks, sounds like a good plan.

 

[labeledbass]

I've heard it called several things but generally you have "Unity Gain" when the input (output of bass, and input of pedal, if available) and output of the compressor are the same, essentially you shouldn't have a difference in volume when cycling the pedal off and on. Like mentioned above some preamps react differently to input, I have a rumble 200 and know if you push the preamp you can get some decent breakup, for what it is (I'm not sure if the 40 is the same though). Again like above I would start getting everything level with each other and go from there. Honestly you should be aligning the bass and compressor to each other, and then separately aligning the Gain and Master. You're going to get more "reaction" from adjusting the preamp gain on the amp more so from the output of the pedal, especially if that "Vintage" button is pressed, it has some compression in its path as well.

 

[John Stephen]

Thanks for the insight -- very helpful.

 

[David Jayne]

The 'Output Level' knob on the comp is there for 'makeup' gain. Meaning, depending on comp settings, the comp may significantly reduce the level from your bass to your amp. So set your amp gain as per usual with comp off, then when you turn on the comp use its level knob to bring the volume back up to the level you get with the comp off. It's simply to avoid volume changes when switching comp on and off.

 

[John Stephen]

Got it, thanks David.