What does it mean when an amp has an "effects loop" ?
most commonly it refers to amps that have a "send & return" inputs/outputs on the back of the amp.
this enables you to place your effects in between the preamp and the power amp rather than placing them in front of the amp. basically it makes the effect "line level" rather than "instrument level"
Thanks TwidtedLefty...but whats the benefit?
the way i understand it is you have a stronger signal, it would depend on how many effects you are using.
it would seem that if you were using only one effect that it would probably not make much difference.
i would use time effects in the loop such as flange, delay, etc.
personally i would not use the loop for distortion or overdrive.
i'm sure others would give better advice based on more experiance, gigging vs. recording etc.
but this is how i've come to understand it's use/benefits.