I just picked up an AC15CC1 that is primed for modding... It already had the "bright" cap clipped, JJ's installed (preamp, PI & power tubes), Accutronics Reverb tank, and FedEx will deliver a Celestion Gold on Wednesday. Tone Cut, V1 Plate Resistor, MM/Heyboer Choke, Standard/Custom EQ (w/ switch), and Sozo Capacitors are already on the to-do list. So far, GuitarPug.com seems to have the best (and most comprehensive) list of AC15CCx mods. Are there any other worthwhile mods/sites out there that I may not know about? I'm also considering installing a tube-buffered effects loop - like London Power's or even Weber's. Both loop circuits are straight forward and the entry point seems clean (just before the PI). Are any experienced modders able to provide advice or insight as to whether or not I should procede with it?