Triode versus Ultralinear/Pentode

No. With my Mesa Baron, Triode is preferred for acoustic and smaller scale music, but adding some pentode helps a great deal with rock, orchestral, some jazz, piano and even solo guitar sometimes. and it solidifies imaging a bit. I suspect it's as we've always heard: it's all in the implementation. Unless you listen only to chamber music, there are times when pure triode is subobtimal.

Lloydc, your amplifier might be a good example of what I meant- that even though there is some advantage of the 'triode mode', that mode is not optimized in the amplifier in order to allow for the switching in the first place. Were it optimized, there would be no trade-offs in sonic performance, only power.

So I take it that if I were to convert the Music Reference to triode it should be triode only, optimized for triode, and not a triode/ultralinear via switch approach.

What does Roger Majeski say about the potential result of the conversion? Benefits v liabilities? There is always some trade off - what does he think they are with his amp?

I asked that question on AudioCircle in the Manufacturer's forum and still have not gotten an answer. To some exent I hesitate with the idea of the mod (he did not object to the idea), thinking if it was such a good idea, why didn't he do so from the begining - could be the amp has more universal application run in AB2 Ultralinear. I know by going to triode, he pull back on the NFB which appears to always be a good thing with my Merlins. I agree in principle (with no engineeering knowledge whatsoever) that it is best to have a unit optimized for one type of operation or the other - the logic of that makes sense to me.