I have an upcoming writing & recording project beginning in the new year with a small budget. We are in need of a single-ended 6L6 tube boutique amp to be used during these sessions with a bunch of high end pedals. Just ran across VHT Special 6 & Special 6 Ultra heads. Does anyone use these? Can you drop a 6L6 output tube in place of the 6V6? Does it have a bias pot? I know VHT encourages DIY'ers to mod this sucker....that is pretty cool. I'd love to here from owners.