Mailist to discuss all issues regarding the Digitech GSP-2101 Guitar FX Processor

Hello all on the list

i have a friend of mine that bring the unit in the subject for a 
strange
problem:
everytime in the patch selected there is a comp/dist that refers to 
the 2
tubes (clean tube, distorted tube, etc.) the overallsignla is veeeery 
weak.
i have substitued with 2 new EH 12ax7 but stangely cant get signal at 
all
(strange that the old works bad  and the new nothign at all O_o).

- the tubes are marked with 12ax7a2 (red ink - no brand) ..i have 
checked
and there arent' info about seem to me to be the most obvious 12ax7 
(but
also may not to be who knows..)

- i have checked all the settings digitally on the patch and at the 
maximum
the problem is the one above .. so it may be not a problem of 
software /
configuration and also adjusted the trimmer signal levelof the 2 
tubes (it
acts but cant reach usable operating levels) but the leve at maximum 
remains
at the 5 % of the operating signal (other than is really bad sounding
obvuously)



Can someone here gimme an hint / help ?
it would be really appreciated.

ps. Digitech sent me soon a well done schematic that anyway can't 
help too much.

thanks a lot,
Paolo.