I’d definitely think SET ownership is dominated by people who largely trust in their listening experiences and weigh more heavily on their subjective listening evaluations than other parameters.
Anyone who has walked into a brick and mortar store in the last 60 years has done exactly this. That is what has kept them in business so long. IOW that's the majority of the market- the 'measurement only' community is a small fraction overall.
With large horns very much effortless scale is the big thing… along with real immediacy… I love big ribbon panels as well for they also have a potential less fettered sense of realism but the dynamic freedom that full scale horns can deliver is something else again for me.
With low powered SET coherence and realism with acoustic instruments and a good SET with the right drivers do both flow and fine resolution.
You might want to hear what those horns can do when you drive them with a musical amp that has greater usable power. With any good system, you want the power amplifier to be loafing, having a lot in common with sitting on a park bench. To give you an example, think of any stereo LP that really brings home the realism. That LP was cut using amps that likely never got past 10% of their total power, and those amps were not SETs but instead if tubes (as was in the case in 1958) were pentode amps with feedback. But the cutter head has a feedback winding and typically this was applied to a 30dB feedback module that wrapped even more feedback around the cutter amp. That continued with solid state cutting systems.
If you're asking what happens when you drive a cutter head with no feedback, the answer is you lose a lot of stereo separation due to how the cutter mechanism is suspended. The feedback helps fix that, as well as vastly reducing distortion, apparently without causing brightness.
We tried using a 300b SET to drive our cutter head. We also tried a refurbished Dynaco ST-70 and also our stock cutter amps; the same track cut three times in the same lacquer. The cutter only needed a little power so the 300b SET was not being pushed hard. But it was the least musical track on the disk. The ST-70 and stock 1700 series solid state electronics sounded remarkably similar. The cutter head only needs about 3 Watts (about 7 Watts will fry it) and is an easy load (about 10 Ohms). The stock 1700 cutter amps make 125Watts at full power. So you can see that the idea is the system is immune to overload. The weakness of course is its very easy to fry the cutter head.
Ralph I do genuinely feel that you see the SET negatives way more than you see any of the positives… in fairness it forms the consistent message and dominant approach that you tend to bring to this thread. Providing technical insights is great… it’s sharing technical subject matter expertise which is valuable but it’s just part of the story and we can learn different things from those who actually choose SET over other choices.
I think it’s great to have people bringing a range of technical knowledge and I’m a fan of reading the technical information that you and others here bring to the forum… its also reassuring that the strong technical bods don’t always agree with each other and that even with objective technical interpretation it’s not all black and white.
This might be because I've spent more time studying them.
You're correct- SETs have more cons than pros. So you can trust your feelings in this case. I don't think there's much of a technical range of knowledge being expressed on this thread beyond Ampexed and myself. I don't see much in the way of EE talent here. I have seen Brad trot out some debunked 'studies' that don't hold up- that's not good enough if you want to get at the truth of the matter. Ampexed has a good solution if you really want to hear what an SET does right (which is to say, not bass).
The thing is, I'm not the one who came up with the cons. They just happen to be engineering fact; the lack of inductance in the output transformer limiting bass is a good example. When you compare any SET on a speaker that can play bass with an amp that can
really play bass you hear right away what I'm talking about. Its not subtle- you hear it in 5 seconds flat.
Now I get that engineering might have a bad name around here. But please keep in mind that engineering is why SETs exist in the first place. There's math behind it- the 'why' of why it works. That same engineering provides an access, if the rules of human hearing are being observed, to build better amps. You may have noticed I've mentioned something called a 'quadratic non-linearity' when talking about SETs. That is why they produce the prodigious 2nd harmonic. That's the math and the engineering- how that works with the rules of human hearing understanding is we know the 2nd and 3rd harmonics add richness to the sound (because the ear assigns tonality to harmonics- its the same reason you can tell the difference between a country fiddle and a Stradivarius) and they can mask higher ordered harmonics.
I've also pointed out why so many PP amps are not seen as all that musical- and what to do about it, such that an SET wouldn't keep up in any way. I suspect some that have been attacking me missed that part. Search on 'cubic non-linearity' on this thread.
What I find adorable is people talk about the SET listening experience as if somehow I don't also listen and not heard SETs for myself.
maybe people more focussed on coherence might just set themselves up more simply
FWIW Dept.:
If you want greater coherence, keep bass out of the SET. Same thing if you run a 'full range' driver for a speaker- keep the bass out of it. The reasons are different for the two but the result is the same- along with smoother sound with greater detail; this is easy to hear and not subtle! Its easy to blend a sub if the sub doesn't make any output above 80Hz as it won't matter where it is in the room if you can hear it at the listening position. If the sub goes higher than that you may have to position it with the main speakers.
My position throughout this thread is- if you want to use an SET and are dead set that's what you want to do, fine; I've provided some tips how to get better sound. I figure if you want even
better sound, why not go for it??
