Acoustic Zen Crescendo

Wig,
Your’re a pure example of what I was describing in my earlier post today regarding higher power amplifiers. Their potential advantages are a matter of sonic priorities of an individual listener.

The very highly regarded Vitus with 400 watts and yet you replaced it with a 48 watt SET. Quite clearly you are very happy with this switch. To be fair I could see someone making the opposite choice to the much more powerful Vitus and being happy.
I can easily believe you when you say it sounds much better. DHT SET just do some things like no other type of amp and this includes push pull pentode type tube amps, they are just different.
No amplifier does everything right for every listener. This is why a person has to know what it is they are searching for as for certain either of these amplifiers are superb in the right setting. Wig, my taste would lead me to the same choice as you.This is not a put down of the mighty Vitus by any means. A well executed SET with enough power is my "just right" cup of tea. Wig I know you are having a ball with your music reproduction.
Charles

Sorry for the late response just been very busy! Yes the Zero's with the Atmasphere and Crescendo combo worked better than just the Atmasphere M60's alone. You are correct that OTL's like a flat high impedance load and I set the Zero's so the Atmasphere saw a 12 ohm load not the 6 ohm load the Crescendos normally present. Got better bass and could play louder and yes the Zero's are not as transparent as going without but we all choose pluses and minuses and in the end the M60's with the Zero's on the AZ was a better sounding alternative.

An OTL would surely welcome a nice easy to drive 12 ohm load, this makes perfect sense. The Triode Corp and Line Magnetic SET amps do very well with the Cresendo's  6 ohm flat load. Both of these have terrific quality output transformers and serious stout power supplies.This is why these amplifiers are so heavy (and sound so divine).
Charles

Wig,

It looks like your amplifier progression was VAC 160i, Vitus RI 100, LM 508ia. Not a dog in that group.
Charles

Lots of amp/pre-amps within the last 7 years:

Belles 350A/Belles 21A Modded caps/power supplies
Herron M1 Mono Amps/ Herron VTSP-3A Pre (loved it)
Vac 160i
Vitus
LM

Speaker:
Vandersteen 2CE Sig II
Avalon Ascendant
AZ

Wig