I know this question has partly been answerd here but my question is : If i use a preamp/effect processor like Digitech GSP1101, what input on an guitar amp should i use, High gain or low gain?
That rack unit can be straight into a poweramp - does your amp have an FX Loop? See page 9 of the user manual. This question is closely related: music.stackexchange.com/q/23323/12202– jonrsharpeDec 1, 2014 at 10:25
The amp is an amp i borrowed in a rehearselroom and i don´t know if it have a FX Loop. My own three amps Marshall MS-2 , Marshall Class 5 and line6 spider 4 (15 watts) doesn´t have an FX Loop.– Harald KjersénDec 2, 2014 at 10:47
And do you want to use the GSP1101 for its preamp modelling functionality, or just effects?– jonrsharpeDec 2, 2014 at 10:50
Both i think, because with just effects it´s perfect for an amp and with preamp modelling too you should run it in a PA system. Right?– Harald KjersénDec 3, 2014 at 13:19
Yes, or if you're using the preamp in the rack unit you should probably bypass the preamp on the amplifier, hence the suggestion to use the effects loop (FX Return will feed into the power amp, not the preamp).– jonrsharpeDec 3, 2014 at 13:21
You should use the channel that is the quietest. Test at low volume first.
I put it that way because some amps define 'high gain' as 'the channel with the highest gain/volume' whereas others use it to mean 'for an instrument with a high output'.
You want the one that drives the amp the least; that's the one it will much prefer as you are feeding it a lot of level from the preamp.