Thank you kindly for the nice words, Hazyj.
I’ve never heard a 30/30, but based on many comments I’ve seen over the years by owners of that amp I would expect that if it provides enough power for your application it should sound at least as good as the 70/70, and perhaps better. One reason it might sound better is that since it has four 300Bs rather than eight there is less possibility for tube characteristics to be mismatched to a degree that might be audibly significant.
I should also mention that I’ve been delinquent in updating my system description. Last year I sold the 70/70 and replaced it with a solid state Pass XA25, which I’ve been delighted with. With my speakers, at least, which have an extremely flat and benign impedance curve, as well as sensitivity in the upper 90s, it comes amazingly close to the VAC in terms of dimensionality, imaging, liquidity, and other traditional fortes of high quality tube amps. It’s a bit less rich sounding than the VAC, but I interpret that as an increase in accuracy, which is fine as far as I am concerned.
Also, my decision to move on from the 70/70 was driven
mainly by non-sonic factors, including the likelihood of greater reliability in
the years ahead considering the age of the VAC (during my seven years of
ownership the VAC required two trips to the factory for repairs, which were not trivial undertakings given its 100+ pound weight);
the fact that even though both amps operate in class A the XA25 puts only 240
watts of heat into the room compared to what I believe is something like 700
watts for the VAC 70/70; and the cost that would be involved in re-tubing eight
300Bs if and when that were to become necessary.
Thanks again. Best regards,
--Al