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

use these:
http://cgi.ebay.com/Tubes-Digitech-GSP2101-Artist-2112-2120-12AX7-12AX7A-/330566860807?pt=Guitar_Accessories&hash=item4cf7520007


> So recently my 2101 gets all squeelie when I run a lot of gain through the 
> tubes. I think they're going microphonic. I'd like to try a new set of 
> tubes but am not sure where to get replacements and what kind to get. I'd 
> like to return it to a stock sound.
 I believe my unit is running the stock GT tubes (groove tubes).
 Anyone have a source and what is involved in changing them? Do I have to 
bias anything or what?
  "Never put off till tomorrow what you can ignore entirely."