I have a confession to make... I had become a bit jaded with the sound of my NCC300s, this has been partly caused by strapping Les' giant EI-core transformer into my Leach amp and getting a very nice improvement in sound. THe NCCs had.s a slightly strident upper midrange, which is common in very many SS amps IMO. I always thought the Leach somehow managed to avoid this, which is why it has been my reference amp for many years.
Anyway, in an effort to design out this "edge" to the sound, I stared investigating the performance of the regulators. The current result of this is that the regs are out of circuit in my amp (the regs are not to blame for the edge) and I'm running with good old fashioned R-C decouping on the front end.
The NCC was powered by a pair of Yamaha EI-core transformers, which I had always thought were pretty good. I estimate they are about 200VA each.
This afternoon I decided I really ought to try the giant EI in the NCC300s. I can't quite believe what I'm hearing. It's bloody amazing!!!!!
Leagues ahead of any of my other amps. The NCC is clearly much better than the Leach - now this it has the right transformer in it.
I still cannot understand why a transformer should affect the sound so much, but who cares? It pleases me greatly!
If I was JMH I would now have to write:
"The revised NCC300 has caused me to have to completely revise my usual subjective scoring system. Previously an item that scored 86 points would only score 36 points on the new system. Please take this into account when comparing this with older reviews...."
NB Thanks Les!!