Hey, who wants to buy a French YBA-designed 3-ch amp?
Russell, thanks for your critique of the power specs. 300Wrms @ 4 Ohms is about double or more the power of my current amp, so that should be sweet.
What do you make of the power @ 2.7 Ohms with one SMPS600 per channel? How might you expect 120V performance to differ, if at all, vs. the 230V test specs?
YBA are wonderful amps in my book, but this brings up a point in reference to what Rclark said about chassis. Yves Bernard André (YBA) told a friend of mine (in 1993) that if it were not for marketing difficulties, he would sell his amps without metal tops and bottoms because they spoiled the sound, and he advised us to take these panels off our own amps for the improved sound. In fact shortly after telling us this, I think he did sell one of his models - an "Intégré" - with an acrylic or glass top. Yves was early into damping components like capacitors, and considered that was an important part of the YBA sound. As a result we at our store damped everything we feasibly could with some black automotive goop - I forget the name. It was one of our secret weapons. It seemed to help almost everything we applied it to, including IC's.
If I were playing with these Ncore modules, I would experiment with minimally enclosing them, metal-wise. I would compare their performance outside of a case with inside, and with metal and wood cases. I notice that the one trial and review was done with these out in the open - no chassis as such. I just would say when it comes time to drop them in cases, pay attention to any potential effect on the sound. Denis Morecroft is no fool - he pioneered this concept, I think, as well as others which have caught on big time:
http://www.dnm.co.uk/materials.htmland with these amps as revealing as they supposedly are, this may be particularly important.
As to the 240 vs 120v question, as well as the 50Hz vs 60Hz factor, I think that with switching mode power supplies this does not make much difference as the transformer operates at a much-higher-than-line frequency, and thus does not need to be bigger as is needed in linear supplies for 120v vs 240v.
As important as the absolute power is the amp's behaviour in recovery from clipping. This was found to be one of the few measurable performance characteristics that co-related with apparent sound quality in a survey done some time ago by HFN in response to the Ongaku sounding so good and measuring so bad. The other, by the way, was the degree to which RF contamination affected the amp's performance. It seems that amps are in some degree of clipping much more of the time than is commonly realized, so clipping
recovery behaviour, which is associated with stability as regards oscillation, is important to the sonic character because most amps are spending a lot of their time recovering from clipping. Clipping drives many amps into incipient oscillation which is ringing, and generally doesn't sound good. Anthony Michaelson of Musical Fidelity speaks honestly about this; few do.
I feel confident Bruno has all this well in hand, though, and is one of the factors contributing to the open, revealing and effortless sound spoken of.
