It looks like you have mismatched your gear slightly, I've always found that you need to match the quality of your guitar to the amp (and the effects)
So a 700$ should be played with a ~700$ amp, not a 200$
practice amp...the GSP isn't that bad (it was originally similarly expensive), but it's 20 years old.
Secondly, the gear you are using is not particularly suited to smooth tones:
-Korean RG
-Neck Through
-Evo
-
Marshall Valvestate
the GSP is also on the fuzzy side of things (IIRC it was Vernon Reid's favorite in the early days of Living Colour, using it for a razor sharp tone, think Dimebag with more processing), but with a little tweaking you could get some decent smooth overdrive out of it.
Unfortunately this amp lacks an FX loop, which means using the GSP in combination with it is virtually impossible: the GSP's output is too hot for the AVT's front, rolling back the volume on the GSP will only introduce hiss and noise.
I suggest you get yourself a decent amp first, and replace the GSP later, go find yourself a GSP2101 or 2112; a relatively simple amp with an effects loop could already solve part of your problem, as long as you know what your doing with the GSP.
A - slighly less crappy
- amp with an effects return would allow this: try to bypass the preamp and use the GSP21.
so:
guitar-> GSP->FX return of Amp
I think the GSP also has an FX loop, on a decent amp with an FX loop you may also want to try this:
Guitar-> GSP input -> GSP FX send -> Amp input -> Amp FX send -> GSP FX return -> GSP out -> Amp FX return.
