SET amp comparable to First Watt SIT 1?

We have a number of customers with that speaker that really like the combination. They use either the S-30 or M-60.

Due to the efficiency of the speaker, low distortion at low power is really important and this is why SETs are often preferred. Because our amps don't have a dedicated separate circuit for phase inversion, they too make unmeasurable distortion at lower power levels, and at higher powers considerably less than either the basic SIT amp or an SET (the latter usually being about 10% at full power).

The advantage of the SIT semiconductor is that it has the linearity of a triode including the soft clipping characteristic. That makes it pretty attractive! The problem of course it that they aren't available- all sources now are from NOS stock or robbed from old Sony V-FET amps.

The challenge that you have is that at 99 db, its actually possible to run many SETs into a considerable percentage of full power. If you are pushing it past about 20% of full power, then you won't be really hearing the best out of the amp has it will start to take on a 'loud enough' (shouty) quality (which is why many SET users say that 7 watts is enough power (because the system starts to sound loud; a system without appreciable distortion will not sound loud), until they hear what the same speaker sounds like with more power behind it. So the SIT amp will have an advantage in that regard.

If you are getting the big Volti with the self-powered woofer, then you will be able to get along with 7 watts or so as long as you are using an active crossover. Then a 7-watt SET will make more sense as long as the room is not too big.

If you're going to stick to a 300b you do have several options. normally a 300b can only make about 7 watts. You will need more power unless your room is a small one, or if you only listen to light chamber music or solo guitar. Musical peaks take real power! My speakers are 98 db (and don't use a subwoofer but are good to 20 Hz) and I find that 30 watts isn't enough; 60 watts works a lot better. I don't play the system particularly loud either- I just like it to sound as real as possible.

You might consider an Electra Fidelity
http://www.electrafidelity.com/a3-500/
It operates class A3, a class of operation invented by Jack Elliano (who makes the Electra-Print transformers). It offers a few more watts, all of which will be precious when working with a speaker at this level of efficiency. The Class A3 operation also offers lower distortion.

I don’t want to bother those people with my ignorant questions,

@tmare, ignorant questions are the best ones! Never, ever worry if you are bothering the manufacturer by asking them; that should be part of why they are there!! Otherwise you might want to rethink how much support you're going to get.

I have owned OTL amps and like many of their characteristics, but I've never heard one, especially using massed output tubes, that has the sheer transparency, speed, holistic tone and spatial precision of Audion SET overall, and especially the Golden Dream monoblocks

Funny- my experience has been the opposite. Our amps have a risetime in the output section of 600V/mS, where the typical SET might be about 10V/mS. So its not only audible but measurable. Usually that's a pretty good indication that its actually real. In addition to the speed, our amps have more bandwidth as well.

Now what is going on with a specific amp on a specific speaker might really affect the outcome of your perceptions (for example a low impedance at high frequencies that one amp can drive while the other can't might make that latter seem slower even though its not). So its a good idea when doing comparisons to make sure that both amps, whatever they are, are in proper operating condition and are also a reasonable match for the speaker being used (that is, if you really want to find out what the differences are between the amps being compared).

@charles1dad  I'm good with that- that's how I would describe it too. You expect an SET to sound fuller as it has more 2nd harmonic distortion where the MA-1 really does not have much at all. I think that if you had a sound pressure level meter in the room, you would have found that although you were careful to match the volume of both amps by ear, that in reality the MA-1 was actually playing at a higher level.

The leaner sound our amps often have is simply that they make less distortion (most of it being the 3rd harmonic, at about or slightly less than an SET will make at the same percentage of power level with respect to full output).

When designing any kind of amp its all about the distortion it makes as to how it will be regarded. For example solid state amps have a lot less distortion but what they do have tends to be higher ordered harmonics which the ear translates as 'bright' and 'hard'; for a solid state designer its the 7th harmonic that is the one to be avoided if possible. I figure those are the drop dead harmonics to avoid if you plan to play the system for hours and hours on end. That way you won't get fatigued.

^^ I get that. I played string bass in the orchestra for years. On that account its always been really important to me to get the bass right. That's an example of my own preference. But because I played in the orchestra I really really don't like it when the system sounds 'loud'. That bugs the heck out of me. I want it to sound effortless even when I'm play real volumes like I've heard in the concert halls with acoustic instruments. Somehow the orchestra could sound effortless and not shouty even though it was playing at 100db! Picky I guess...