Oh boy, where to begin? Firstly, I should say that I have been an Atmasphere S30 owner for the past 4 years. It is simply the best amp I have owned. They have a speed and transparency that, IMHO, no transformer-based amp can match.
The original futterman design and the NYAL clones of Harvey Rosenberg where notoriously unreliable and unfortunatly this reputation plagues current OTL manufacturers to this day. I only have experience with atmasphere(AS) which has run flawlessly. AS/tenor/joule amps are NOT futterman designs/clones and it's unfair to lump them together under the banner of "OTL".
Regarding the heat issue, any class A amp, like AS, will run hot. This includes tube or solid state. Yes, the big AS amps (225 and 140 watts/ch mono) can mimic "space heaters" but in actuality, it is my understanding, that they run only 10% hotter than their class A solid state equivilents.
The big AS amps will drive 4 ohm loads easily. With the S30 and M60, speakers have to be chosen more carefully.
Finally, about price. My S30, as optioned, went for $3150. It smoked a pair of well known SET mono's that went for $6000. I don't want to call AS amps "bargins" because they are expensive, but for what you get I do think they are one of audio's best values.
The original futterman design and the NYAL clones of Harvey Rosenberg where notoriously unreliable and unfortunatly this reputation plagues current OTL manufacturers to this day. I only have experience with atmasphere(AS) which has run flawlessly. AS/tenor/joule amps are NOT futterman designs/clones and it's unfair to lump them together under the banner of "OTL".
Regarding the heat issue, any class A amp, like AS, will run hot. This includes tube or solid state. Yes, the big AS amps (225 and 140 watts/ch mono) can mimic "space heaters" but in actuality, it is my understanding, that they run only 10% hotter than their class A solid state equivilents.
The big AS amps will drive 4 ohm loads easily. With the S30 and M60, speakers have to be chosen more carefully.
Finally, about price. My S30, as optioned, went for $3150. It smoked a pair of well known SET mono's that went for $6000. I don't want to call AS amps "bargins" because they are expensive, but for what you get I do think they are one of audio's best values.