How do effects loops on guitar amps work? I don’t know. They must be magic.
As I have been for the last few weeks (when I have time), I’ve been playing with a friend’s Mesa Boogie Mark IV. It is a lot of amp! Three channels. 30 to 85 watts of power. 12 inch speaker. Built in reverb. Recording line out. Built in EQ. Two effects loops. Master volume. Etc.
Currently, I have reconfigured my pedal board so that half my pedals go through the front of the amp and the other half go through the effects loop. It is pretty cool from a technology/geeky stand point. I’m still exploring how the different pedals color the three channels of the Mark IV.
The area in which the effects loop is most obvious and most useful is with the Boss RC-20 Loop Station I’m using. With my Vox AD50VT I could not take advantage of the modeling amps with the loop station. I had to get a clean sound through the amp and then use only my pedals to get different tones and effects in whatever I was looping below my playing. The effects loop makes it possible to use the three channels with the loop station. I can layer a clean or chunky rhythm line and then layer arpeggios on top and then play a screaming solo on top of all that. I will say that this experience has certainly shown how bad my timing is and how I have not explored the possibilities of the Loop Station.
Anyway, I’ve got my tremolo, flanger, analog delay, and loop station in the effects loop. I kept my Boss TU-2 tuner, EH USA Big Muff Pi, Marshal Guv’nor Plus, and Morley Wah in front of the amp. Having the three channels really eliminated much of my need for the big muff and guv’nor. I could just go between the three channels of the amp. I will admit that the guv’nor sounded pretty good on top of a fairly clean channel two, but I could just turn up the gain on channel two for the same effect…and it sounded better.
The other nice thing about the effects loop on the Mark IV is that it has its own button on the amp foot switch. So I could take the effects loop out or bring it back in any time I wanted. Getting rid of my overdrive, distortion, reverb, and A/B channel switcher would clean up a lot of space on my pedal board. Then I could add in a digital delay and a few other cool things.