Who makes

The way to get a conventional solid state amplifier to operate in the Power Paradigm would be to add some current feedback, but not so much that it acts like a 'current source' device.

To my knowledge, no such products exist - for now. If you want to take advantage of Power Paradigm principles, you will, for the time being, have to use a tube amplifier.

The Nelson Pass amps I referred to earlier that act essentially as current sources and therefore have very high output impedance are listed at his "First Watt" site here. (His amps that are marketed under the Pass Labs name are of course voltage paradigm amps, as Bruce indicated). The ones I was referring to, which I suppose could be called "current paradigm" amps, are the F1, F1J, F2, and F2J, which are indicated as no longer being produced. The literature provided at the site indicates that they are of course only suitable for use with a limited number of speakers, primarily those using just one driver and providing high efficiency.

What may be more interesting, though, are the currently produced SIT-1 and SIT-2 models, which I hadn't been aware of previously. Based on a quick look at their descriptions, specs, and manuals, those would appear to be true solid state power paradigm designs, although their power ratings are limited to SET territory at 10 watts.

Best regards,
-- Al

12-02-13: Bifwynne
Al or Ralph, if you can simplify or clarify what I just said, I'm sure I and the other readers would appreciate your edits.

You said it all clearly and well as far as I am concerned, Bruce, aside from a minor miswording that I suspect was inadvertent: As you probably realize, damping factor is not measured in ohms. Since it is the ratio of two impedances, it has no units.

Best regards,
-- Al

Hi Bifwynne,
It doesn't seem that Shakeydeal was making a proclamation but rather just
stating an opinion about his preferences. I know this is of course pure
subjectivity but I understand his rationale for feeling that way.
Charles,

12-02-13: Bifwynne
Suffice to say that a speaker with highly negative (i.e., capacitive) phase angle and low impedance characteristics in the power spectrum (say 30 to 400 Hz ??) can really give a tube amp, even a SS amp, a bad day. That in part makes for a tough to drive speaker that calls for a "current" beast like a Bryston or Krell SS amp.

That is another good point. Is the current output more important than the voltage as that is what gives the speaker its dynamic range? What is voltage good for? It seems like a cheap way make the amp appear to be powerful when reading the specs.
Thanks all. I will have to give this some thought. Previously, I had the simplified idea that if a speaker is over 8 ohm, and especially 16 ohm like those back in the 60's, you need tubes because you just won't get any power out of a reasonable sized ss amp.