I was wondering if any of you folks could help me. I was given a Sonic 1 as a basket case, and here's the problem.. First of all the tube chart is gone, and is the front panel containing the grille cloth (if you know anyone who has one I would greatly appreciate the lead), so I don't know what phase inverter tube goes in it. I heard the early ones came with a 6AN8, and the later ones came with a 7199. I took a look at the schematic for the 7199 model here on this site, and it is fairly close to what I have, but has some of what I would call considerable differences mostly regarding pin 7, and the treble pot. Just to make matters worse, there is no date marked on the chassis, this is the first time I ever saw this. If it helps there is a what looks like a metal foil sticker on the chassis for the serial # it has since rusted almost totally, but I can make out a few of the numbers... they are 2006. Does anyone out ther have a schematic for the 6AN8 version? Any help, and or information on this amp would be GREATLY appreciated. Thanks Bill