Dear all, I am back. Progress report: I have successfully produced my first circuit boards, though not for the AVT50 yet (these will be next, I am currently modifying the design for the AVT50 board a bit more, and improving my procedures for making circuit boards). I have had to face some challenges. I am awaiting parts I ordered for the AVT50 mods. I have ordered enough parts for about 13 kits. Some of the parts I am searching for are a bit hard to find - I may have to alter my designs a bit if I can't locate them. I plan to have the kits out before the end of 2008. Thanks for everybody's interest.
Dear Arcarix: the extension speaker jack mod is the easiest part of the kits, when installing tube gain. Have no fear, instructions will come with the kits. As for the speaker, I am using a 4 ohm celestion g12m70, which, IMHO, matches up with the amp beautifully. As for speaker impedance, using a speaker rated at a higher impedance than the amps is harmless, but if you run an 8 ohm speaker in a 4 ohm amp, your power gets cut in half. if you run a 16 ohm speaker in a 4 ohm amp, your power gets cut in 4. 4 ohm speaker with 4 ohm amp=100% of your power. WARNING: NEVER USE A LOWER IMPEDANCE SPEAKER THAN THE AMPS IMPEDANCE RATING, AS THAT WILL CAUSE SEVERE DAMAGE TO THE AMP.
PETER