I recently bought a new head and agonized over whether to go the Ampeg route. I decided on the AG500SC for its warm solid state tone-clean, practical and powerful (I found the saturation on the dual channel version a bit lacking hence the SC) but I've been thinking how good it would be to have Ampeg toney goodness at the flick of a switch. Enter.... the Flipster. This little gem on the Runoffgroove.com http://runoffgroove.com/flipster.html is essentially the preamp section of ye olde Ampeg SB-12 with the 12ax7s replaced with with jfets. sound clip I just finished a breadboard build and it's really sweet. My version is probably a bit softer that the sample. Each of the jfets has a trimpot (adjustable resister) to in a sense you can tune it to get the sound you like. I'm in the process of etching a board and building a case - so will post progress updates. If anyone's built one of these I'd like to hear. It'd be good to swap notes. Many thanks to ROG for this awesome adaptation.