Hi Myles, Thanks again for you help getting the SAG-12AX7-M MPI for my Fender Hot Rod Deluxe. I now have the GT 12AX7-M in V1 and V2, and the MPI in V3. The amp sounds great - warm, fuzzy, articulate, and the More Drive channel is actually useful now, although I mostly use pedals for OD and distortion. Never one to be satisfied, I am now wondering about the optimal bias setting for my power tubes. I put a set of GT 6L6C's with a hardness rating of 4 in to replace the original issue GT 6L6B red label. I lost a little clean headroom, which is OK. Is there a 'best' bias setting for these tubes to have them performing at their optimum, and if so, what is it? I have a digital multimeter, so I can use that and the bias test point. I think Fender factory recommend is 60ma at the bias test point, while some say 68 or higher is best. I don't really want to chance burning up my tubes by constantly changing the bias setting. Can you advise me on this? Thanks Stan