What I would give for one ! :tears:
convitcon,
may I ask where you live ?
The "mod" can currently be made only on the B-1, because it´s V-Fet transistor´s housings are big enough, to include a modern high power transistor and some circuitry (the magic) arround it. It is also currently bound to N-types, but I try during the next months to solve this. The replacement transistors will be rather high price, so it shouldn´t make sense to mod a TA-5650 with them.
The TA-N7(B) and the TA-E88 (as well as the Wega version Lab Zero) form a dream team, which can be considered to be the best of the Senventies. I never had a chance to hear them on a pair of NS-1000´s but I´m sure I´d love to.