Tube amp power watts equivalent to Solid State?

I have a Cayin 35 watts tube amp. What is its equivalent to a solid state amp?
Bob, I look at the relationship between amp type and speakers this way. I suspect we are probably saying the same thing, but just a little differently.

For example, asssume a speaker was voiced/designed to be driven by an amp having a very low output impedance, typically a SS amp. Also assume that the speaker has a ruler flat frequency response if driven by a SS amp, even though its impedance varies as a functiomn of FR. As a result, regardless of whether or how much the speaker's impedance changes as a function of frequency response, and correlatively the amount of current/power the amp produces, the speaker should hopefully have a flat frequency response as a function of frequency -- as posited.

By contrast, if that same speaker is driven by an amp having a "high'ish" output impedance, typically a tube amp like an Atmasphere OTL, then the interaction of the speaker's impedance which varies as a function of FR and the amp's high'ish output impedance will produce sonic colorations because the amp will deliver current/power in amounts that differ from what a low impedance SS amp would deliver.

I'll leave the theory to the EEs, but I believe it relates to Ohm's Law.

Where amp and speaker matching get interesting is in the in-between world. For example, my ARC Ref 150 tube amp has a rated output impedance off the 8 ohm tap at low frequencies of something between .6 ohms and 1 ohm. As a result, there is some sonic coloration if the amp drives speakers designed to be driven by a SS amp, like my Paradigm Signature 8, but the coloration is quite tolerable. Perhaps a tad tipped to the bright side because impedance peaks at 20 ohms at the 2.2K Hz x-over point.

I suppose in a perfect world, a speaker with a ruler flat 8 ohm impedance curve and zero phase angle over its entire FR spectrum would be able to do double duty as both SS amp and tube amp friendly.


Tube amps if my memory hasn't gone on the blink have a higher dynamic headroom, generally speaking, than solid state amps, giving the impression of more power than is really there. IIRC many tube amps have a dynamic headroom of around 3 dB so that's what, double the power?
Apologies. As Almarg pointed out, I was comparing one tube amp to another tube amp rather than tube to SS. Duh. Only point, I guess, is that SET amp watts are more potent than push-pull amp watts, and nobody asked about that. Sorry.

To clarify something else, the speakers I've been driving with my 12-watters include ProAc Response 3 and a variety of Gallos, all in the 86-88 dB range.
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