SET vs OTL

John,

Glad to provide a laugh.

Your last comment is interesting in that I had posted earlier looking for info on loudspeakers that provide:

A) Appropriate sensitivity and load for a 45 SET amp

and

B) Sufficiently flat and extended bass response to even judge the bass capabilities of these amps (i.e.- no biamping).

Zu's full range passive (Essence?) looks like it might qualify. Any thoughts on this or other candidates would be appreciated. Again, budget and availability are considerations here.

Martykl,

You really can't ask a question like that without specifying your desired loudness level. 80 dB vs 100 dB - 10x the power!

I recently spent some time driving the 90 dB/W DeVore Super 8 with a pair of 45 monoblocks. I tried it at first just as an experiment, and I discovered, with listening levels of 80 dB on peaks in my large room, the (jazz) bass lines were incredibly articulate - perfectly sculpted. *Much* better than the 300B monos I'd just been using.

Is this a recommendable real-world combo? No, of course not - not unless you listen pretty quietly! My point is that, despite the inappropriate pairing, I could still evaluate the bass of these two sets of amps - and, in both cases, it had exactly the characteristics I have come to expect from these two output tubes. (And, while, again, not recommended, this combo was so good I left it setup this way for weeks. I'm trying to train myself to like lower SPLs anyway - and with this setup I could.)

If you want examples of speakers that can be driven cleanly and dynamically to moderately loud levels with a 45 SET amp, and have bass flat to close to 20 Hz, I can give you two: HE versions of Audio Note AN/Es and Supravox field coils on open baffle. The latter supported by powered subs (TBI) below 50 Hz.

If you want LOUD levels, I think you have to go to front horns and/or speakers with powered bass modules (Zu, others).

Typo - of course I meant 100x the power required from 80 dB to 100.

Johnk has no clue but he talks a good game.

If he had experience with flea power SET amps that Paulfolbrecht and I do, his comments would be somewhat valid.

Ignore him.

Now, I happen to like JohnK, and some people do prefer the 300B. I never quite have - but they do have their own strengths and can sound very nice (of course).

Surely they have the ability to drive well speakers that 45s can't hope to.

[I meant to point out that my TBI subs are driven from high-level (amp) outputs, meaning I am hearing the bass signal produced by the amp, not the preamp.]