Tubes/SS Power Amps?

Orpheeus10, You mentioned the system by which stereophile rates and then puts amplifiers into classes. Just for clarity, these were the amplifier classifications I was talking about.

Conduction angle classes
Class A
100% of the input signal is used (conduction angle Θ = 360°. The active element remains conducting[6] all of the time.
Class B
50% of the input signal is used (Θ = 180°); the active element carries current half of each cycle, and is turned off for the other half.
Class AB
Class AB is intermediate between class A and B, the two active elements conduct more than half of the time
Class C
Less than 50% of the input signal is used (conduction angle Θ < 180°).
A "Class D" amplifier uses some form of pulse-width modulation to control the output devices; the conduction angle of each device is no longer related directly to the input signal but instead varies in pulse width. These are sometimes called "digital" amplifiers because the output device is switched fully on or off, and not carrying current proportional to the signal amplitude.

The above is sourced from Wikipedia.

Orpheus10- I think Phaelon is on to something. Perhaps you have Class A operation confused w Sterephile Quality ratings? All Class A operation amps run hot because their active elements (read transistors) are carrying current all of the time. The heat from Class AB amps vary, as they can be designed (biased) to run more in Class A or to switch to Class B sooner. Not all excellent SS Class AB amps run hot. For example, the McCormack amps I owned all never got more than warm. McCormack amps modified by Steve's SMcAudio are outstanding amps if you want to get something that runs cool. A cooler running tube option would be one of the ZOTL amps from David Berning. Or consider higher eff speakers that can be run w "smaller" tube amps like the RAM RM-10.

Guys, I appreciate that Orpheus asked about SS/tube amps and raised a specific concern about heat. I think many of the posts above are excellent and responsive.

However, it's unclear whether Orpheus has considered electrical compatibility with his speakers. Not sure that Orpheus mentioned what his speakers are. Look . . . I own ARC tube gear. I love it. Put tractor tracks and a cannon on the gear and you'll have a tank -- for me, 4 tanks.

Even still, the articles I cited above do a great job explaining electrical compatibility issues with tube and SS amps. In fact, the issue is even more subtle because if a speaker was designed and voiced to be driven by one type of amp versus the other, matching the wrong amp can affect the acoustic presentation.

I'm done harping. I just think electrical compatibility is the first thing to get out of the way.

Cheers.

I'm sure you've heard about the generally different distortion characteristics between tube and solid state amplifiers. I find the difference quite dramatic and I'm driving my tube amplifiers with a solid state preamplifier.

If it's simply a matter of heat, Carver tube amplifiers power tubes actually run cool to the touch. My plasma display puts out much more heat than the Carvers.

Phaelon, I'm well aware of what you were speaking of and class AB probably sounds as good as A, and runs much cooler. Class A is too extreme as far as heat is concerned, and I wouldn't have one. After all is said and done I'll probably end up with tubes, but as I stated before, I've never even heard a top of the line SS amp.