SET vs OTL

The problem I have with a previous post is with the use of the word "superior."

This presupposes that:

1. The poster is the arbiter and ultimate authority of what’s superior

2. Superiority is a given or an absolute

It would be infinitely more accurate to say you, or I, or we "prefer"

...which surprisingly (or is that unsurprisingly) is used to describe the state of those who "prefer" SET amps.

My point is that the words we use are important...

Let’s use them with greater care and strive for comity in this amazing hobby of ours.

[On "superior"]

So far to my Ears with my current experience OTL are superior over any SET Amplifiers in almost any way and so far over any Solid State Amplifiers too.

...OTL Is Superior Amplifier ( I dont intend to tick anyone off) This is based on my life journey as a Audiophile.

[On "preference"]

If you want super lush sounding or slightly colored music then SET would be your weapon of choice but that is more to do with preference

Couldn’t agree more. Words are important. Let us strive then to use them with accuracy and precision.

Author means from or of itself- autonomous, automatic, etc. Everything then is everyone’s opinion. Yes even "facts", as the choice whether or not to consider something a fact is itself a decision someone made. There is no getting around it. Never has been, never will be, any Divine providential entity posting from on high.

This being the case then it is redundant to be qualifying everything with "in my opinion" or anything to that effect. To be redundant is just plain sloppy writing. Only thing worse would be to apologize for doing nothing wrong.

2. Superiority is a given or an absolute

This is correct.


IMO/IME the OP question is a bit too broad. Some OTLs sound more like SETs (like ours, due to no feedback and otherwise masked higher ordered distortion content); some sound more like traditional PP tube amps (due to feedback, combined single-ended and PP circuitry, and the use of pentode output tubes).


All these things make and enormous difference in an OTL because there's no transformer to hide what's going on.


On the SET side, you have traditional SETs, parafeed, Loftin-White circuits; Jack Elliano developed a class A3 output system (which he patented; it seems that Western Electric is using his system) and believe it or not some SETs employ feedback. They all sound different, and they also all sound different depending on whether you have a type 45 output (arguably the ’best’ since they have the widest bandwidth although they are not the best in that they have almost no power), 2A3, 300b, 211 and so on, and whether there are paralleled output tubes and of course how well or poorly the output transformer is designed.


Its also important that if you are doing a comparison, that both amps be comfortable on the loudspeaker chosen for such a comparison. Smaller OTLs need higher impedance speakers, but if you want the best out of any SET, higher impedance (16 ohms) works out well in their favor as well! I think @pani did a good comparison between his amp and the Tenor on this latter account. But while the Tenor used many of the concepts we pioneered (fully differential voltage amplifier, Circlotron output stage) it was a *very* different sounding amp from our stuff.


So I agree you can’t make blanket statements, but IMO/IME you can indeed make very specific statements! For example I’d put up our S-30 against any of the more expensive Audio Note amps out of Japan and as long as both amps were comfortable with the speaker load, expect the S-30 to be better in every way that can be described. But there are some speakers that the Audio Note amps can drive that the S-30 cannot (to be specific: 4 ohms) and in those comparisons the S-30 would fall flat on its face. So I imagine that its important to pay attention to what the designer of the amp had in mind when it comes to loudspeakers.


IMO/IME the distortion signature of any amp is far more important than what kind of amp it is. If the amp has, as its primary distortion product, enough of the lower harmonics to mask the presence of the higher ordered harmonics, you’ll get that organic musical sound that so many SET users crave and it won’t matter if the amp is SET, OTL, solid state or class D.

I owned an OTL amp for 8 years and then switched to SET. No one has mentioned that OTL amps require many output tubes. For example, my OTL amp had 8 output tubes. The obvious issue is that OTL generates a lot of heat, but also with that many tubes, there is more potential for tube hiss and other tube related noise. I was always tracking down a gremlin. My OTL amp always had tube hiss through the speakers, but the more annoying thing was dealing with tracking down the cause of humming noise that would arise. When my amp was quiet (albeit with the hiss still there), it was glorious. I’m not saying that other OTL amps such as Tenor or Atmasphere have noise related issues, as I have no experience with those brands, but mine did.

My current SET amp has been 100% reliable since I got it over 5 years ago and is the most quiet tube amp that I have ever owned. I have gone through a lot of amps over the years. One thing I really enjoy about my SET amp is that I can more easily tell the difference between tubes, cables, and source components. With my OTL amp, the differences were much more subtle. For me, I would not say that OTL is "superior" as that has not been my experience. I would like to re-visit OTL one day, but I am thoroughly enjoying my SET amp so there is no rush.

@thaluza  I think you're overgeneralizing.

https://www.lineartubeaudio.com/products/zotl-40-reference-amplifier