Why not more on 845 SETs?

Twl, you seem to be writing off the use of SET amps with "conventional" speakers and I think this is needlessly restrictive. This is, or was, certainly the conventional wisdom and helped keep me from enjoying SETs for a long time. Then I discovered that certain speakers, despite their moderate sensitivity levels , were extremely SET friendly. Examples of such speakers from my personal experience are the ProAc Response 2, Response 3, Gallo Nucleus Ultimate, and Gallo Reference 3 (my current speakers). How can you tell which conventional speakers are going to be "SET friendly?" Well, you can start with something in the 88db sensitivity area whose impedance rarely or never dips below 8 ohms and whose crossover networks are very simple, but mostly you have to listen and see (or rather, hear). I'm sure glad I did. Dave

Perhaps a SET amp would perform best with a single driver speaker if one were looking for the simplest path, but that does not mean that it won't sound excellent through a dynamic multiple driver speaker. And with a single driver speaker you may not get much bass and I can tell you the bass the Ios/Trentes is deep and tight! I thought of this analogy: with some amps the Trentes are like a water skier being pulled by a sluggish boat; they just never get up and going. But with the 845-based Ios the Trentes get up, go and sing like a slalom skier on a glass-smooth lake at first light. Beauty, eloquence, dynamics.

The Gallo Nucleus Reference 2 (with full InSound/OmegaMikro upgrades, no crossovers, three 6.5inch Dynaudio drivers wired in parallel for 9ohm impedance, OmegaMikro wiring throughout, [?] 330 degree CDT tweeter, which more closely matches the dynamic drivers for radiation patters, and time aligned, 9ohm, 90dB/w/m) coupled to Viva Verona XL 845 tube amps (26wpc) has to be the best "all-rounc" performance I've heard from a SET system to date! This was for both full symphonic orchestral music as well as electronic "rock." It had a full, rich, immersive, and immediate sound.

I've heard a few other demos with 845 SETs. Each time I wanted to "not like the sound" as I _*knew*_ the sound should be less pure than a lower powered tube like a 45, 2a3, or 300b. But so far I haven't heard an flea powered system that I've like as much as the two 845 systems I've heard. I did go to MAF one year, but show conditions are only so good. I really could't draw conclusions in that environment. But without hearing a 845 SET, I would have though (on paper, with no first hand experience) exactly as Twl does. Maybe if I listened to more, properly set up flea powered systems I would think along the lines of Twl. But for no, I can't given what I've heard.

But I still covet that gallo/845 system. I was a good balance of positives with a healthy balance of negatives that I could tolerate long term. If only I could afford such a system!

Dave, not really "writing them off", but just mentioning that there can be some things that go beyond what is normally expected.

I'm not saying that single-driver speakers are for everybody, but I am saying that there is a certain synergy between them and SET amps that can be very productive if used properly. I know that single-drivers are frequency restricted mostly in the bottom end, and that alot of people cannot abide that restriction. However, when going to multi-drivers, some of the really good things about a SET amp are somewhat deteriorated, due to the things that happen with multi-drivers.

I really probably should have worded my post a little bit softer, but I do feel pretty strongly about this issue.

That said, I have no aversion to people using SET amps with multi-drivers themselves, if the users prefer that option. After all, it is what the individual prefers, and not me, which is the critical issue with each person's system.

I guess what I'm trying to say is that in my opinion, there is more to be gained by a good match in the amp/speaker combo with a low power SET/single-driver, than there is from having the higher power SET and using multi-driver speakers. In effect, having a low power SET with high-efficiency speakers will allow the same/similar SPL in the room as a higher power SET with lower efficiency speakers. So the listening level issue is somewhat moot. What's left is the sound quality, which IMO can be better by using a scenario as I outlined above, which can yield an overall system distortion profile that is audibly more palatable than other type while still yielding less signal losses(thus preserving the musical detail and life). Doubtless, some will disagree, and that's fine. This is just my point of view.

I don't expect everyone else to subscribe to this, and certainly am not suggesting everyone should. I'm simply pointing out an interesting factor that might be important to those trying to extract the most information out of their system, with the least objectionable results(from my point of view).

Your description of "SET friendly" speakers seems to be a good one. I'm sure that they all work fine with a moderate to high powered SET, and would sound great. I'm glad that you are enjoying the "SET experience", as I am.

As always, I'm just trying to make subjects for discussion here, and not making any "rules" or "judgments" about anyone else's system preferences or opinions.

IMHO, and YMMV.

Denis, please keep us in the loop over time as to how you find these new amplifiers. It is a rare audiophile who can really articulate what how something truly sounds, without adding their own personal biases, among other things. Over the past month, you have demonstrated an uncanny ability to actually hone in on the sound of a component. It will be exciting to hear how this component measures up for you.