Tube Watts vs. Solid State Watts - Any credence?

Large amounts of dynamic headroom can be viewed two ways: The amp can put out a considerably greater amount of power for relatively brief periods of time than it is rated to deliver continuously, or the amp can **not** sustain power outputs that are close to its maximum instantaneous capability for longer than relatively brief periods of time.

I agree with Ralph/Atmasphere that in general it would be wise to consider a particularly "good" dynamic headroom spec to be a caution flag.

It's also worth noting that relatively low powered SET amplifiers are often considered to be especially good when it comes to reproducing musical dynamics (due particularly to how their distortion characteristics vary as a function of signal level, as Ralph has explained in the past), yet as class A amps they have zero dynamic headroom.

Best regards,
-- Al

"The amp can put out a considerably greater amount of power for relatively brief periods of time than it is rated to deliver continuously, or the amp can **not** sustain power outputs that are close to its maximum instantaneous capability for longer than relatively brief periods of time."

Al, what's the difference other than worded?

Is there an amp not capable of putting out more power cleanly for a shorter period of time? Soft clipping amps which tend to lessen the need considerably and enable fewer watts to "go further" perhaps?

In any case, one wants to avoid the extra distortion that most amps will produce when pushed hard by not having to run them too hard. I think that's a good rule to follow in all cases.

A worse amplifier has higher dynamic range? Worse how? Because it clips easier? And therefore has more gross distortion at volume? Because it has less dynamic range? Worse it has an order of magnitude higher THD than the "better" amp? I see where this is going. :-)

You educated guys now totally confused the hell out of me.
So what should I want? Class A 500 wt/ch tube amp?

One strike against Class A tube amps in particular is their very high cost, has anyone actually checked out what a good 100 Watt Class A tube amp goes for? Hel-loo! One assumes you're NOT referring to milli watt SET headphone amps, not that there's anything wrong with them as all.