Peter, I am definitely interested in buying your mods when you are ready to sell them.
I'm about to replace the current 8 ohm speaker i used to replace the stock speaker. 4 ohm 12" spkrs seem to be difficult to find, however I have found a source for Jensen C12-N spkrs.
I e-mailed the owner asking if it was a good fit for the AVT-50, and here is his reply (I'm not affiliated with these people, and havn't even bought the spkr yet so I don't know how they sound)...
"hi, i found the C12N-4 to be a perfect speaker for that amp.
dont be fooled by the cost... this is a really articulate musical instrument speaker.
here is the link... feel free to log in and use the shopping cart to calculate your exact cost to your door please:
Jensen C12N-4 - VintageSpeaker.Com
ps we only take PayPal or Money order, we are a distributor.
thanks in advance,
Joseph A. Scinta
President KEN-TON Electronics Inc.
187 Greenacres Rd.
Tonawanda, NY 14150 (716-837-9168)
PRODUCTION Facility:
KEN-TON ELECTRONICS INC
2256 Sheridan Drive
BUFFALO NY 14223 (716-875-5114)
VINTAGE SPEAKER LOGIN
Main Phone: 1-(716)-837-9168 Fax: 1-(716)-833-3319j"