Is SET amplification where we should all end up? I keep reading posts where people tell of their journeys from plenty power to micro power, and how amazing SET amplification is 45 set 211 set 845 set otl, and usually, ....with the right speaker. I have yet to read of anyone who has gone the other direction from SET, to High watt beast class A amps or others. If your speakers can be driven by minimal wattage, is this the most realistic, natural sound we can achieve? versus say, 86db sensitive speakers and a 1000w amp? Is the end result solely based on speaker pairing? circuit? tubes?
I am in the process of changing my direction in my search for realistic sound, just because, and wondering if this really is the best direction to be going. From what I have been reading I think it may be.
Is SET amplification where we should all end up? I keep reading posts where people tell of their journeys from plenty power to micro power, and how amazing SET amplification is 45 set 211 set 845 set otl, and usually, ....with the right speaker. I have yet to read of anyone who has gone the other direction from SET, to High watt beast class A amps or others. If your speakers can be driven by minimal wattage, is this the most realistic, natural sound we can achieve? versus say, 86db sensitive speakers and a 1000w amp? Is the end result solely based on speaker pairing? circuit? tubes?
I am in the process of changing my direction in my search for realistic sound, just because, and wondering if this really is the best direction to be going. From what I have been reading I think it may be.
What do we get with SET? What do we give up?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Finally after some 40 years in audio, I finally got to hear a SET amplifier in my WBer assist speaker system. Yes, SET is the ultimate amplifier. Why? Because high sensitivity WBers are the ultimate speaker experience. (excluding big horn systems of course, obviously...)
With the DEfy7 and a friends own design of a EL34 amplifier, both offer too much power to allow the linestage frredom in the vol gain pot. Its just too much current. The tech geek also has his own 250 SET tube amplifier he designs, and finally got a chance to power it up with my new WBer speakers. Now I a, able to use the vol gain on the DPL at much higher gain with no stress on the speakers.
The WBers are 92 sens, the W18's are 87. The 250 tube SET is 6+6 watts. And the sound is like the Defy/kt88 and EL34, but with superior gain on the DPL , now the wonders of the gorgeous inner design of the Jadis DPL can kick in its magic, which was basically locked up with the 2 big PP amplifiers.
For me, the ultimate sound system, starts and ends with SET + WBers. (or big horns if you can afford)
No doubt about it, PP amplifiers are always trumped by SETs.
You know,,,I 'm wondering,,,the 6 watt SET really drives the low efficiency Seas W18's with massive punch in the bass.,,, The Defy can do the same punch on the W18's, but at a much lower gain on linestage. With the vol gain at 9 oclock on the DPL with the Defy/ and EL34, small listening rm, near field,, thats quite enough SPL.. Now with the SET, I can go 12 oclock on the Jadis DPL linestage showing no stress on the speakers and the music is a ~~~bit more~~(are not we all after the nunaces and gains) , detailed, more alive, more colors/deeper soundstage.
IOW the Jadis Linestage now is unlock and can add its charms along with the gorgeous 250 tubes magic.
EL34/KT88 have their tube charms, but seem to be more of a POWER tube, vs a SET's ability to deepen the soundstage, and so i am hearing nuances missed with PP tubes.
IMHO SETs are the best musical amplification. Have not heard a 300B tube, but know from others testimony, its not their cup of tea. Trying right now to find a 845 amplifier, that is within my limited budget. Have my eye on one, , waiting for the lister to respond.
SET + High Effiiciency, match made in heaven.
~~~~OP 2009, and here i am in 2021 getting Mike's drift.
If you like what you hear with an SET based total system, and can afford it, then that's the way to go. However, if low efficiency speakers make a come-back and you like their sound better than your SET based sound, you'l need some new electronics.
I learned the lesson of speaker efficiency a long time ago. When I hear systems that have low efficiency speakers and a high power amp, they sound 'little' compared to what I'm used to...
It is interesting that one can box yourself in with a lower watt tube amp, and deny yourself the vast multitudes (and clear large margin majority) of 83 to 90db efficient speakers...I check efficiency in every review and simply say meh...it will be a while before I lose interest in efficiency, and I'm happy with the sound of my massive 12 watts into horns...the dynamics are there, the clarity is there, the musical "correctness" is there, and I'm there.
Not sure how you define "mainstream" - "all high sensitive speakers (excluding Klipsh) are not mainstream today." While they may be in the minority, there are many manufactures of high sensitivity speakers.
Most of audiophiles have zero experience, with high sensitive speakers. The reason is - all high sensitive speakers (excluding Klipsch) are not mainstream today. When I first time (17 year ago) listened Lowther in Oris 150 horns with 2a3 SET monoblocks, I felt like a middle-age knight who saw a tank :-) I understood that anything I heard before where toys (including Montana, Wilson Audio, Martin Logan, Dynaudio, Spendor, Focal,....).
I can't tell if my amp is loafing, and I've used the iPhone meter for years out of curiosity and to test relative channel levels...no idea how many watts my amp is actually using as I don't own whatever gear would tell me that, but it sure seems clean even at uncomfortable levels.
Its this phenomena of *sounding* loud that's what I'm talking about.
Agreed I have compared a PSET with KT150's 16 Watts or so vs the OTL's and it distorts after 70% or so, that impression of playing loud to me was plain distortion. My speakers are 96 db not 100 db so I think it could get better but don't know how much more.
I think a low sensitive speakers
fashion
is a huge delusion of Hi-End market .
I totally agree!
This drives my 99db Heresy IIIs to as loud as I need to hear 'em with plenty of headroom left.
Its this phenomena of *sounding* loud that's what I'm talking about. My speakers are 1 dB less and my room is not particularly large; I find 30 watts to be a nice minimum power. This means the amp is loafing all the time. When an SET or SEP is making over 20% of full power, the distortion is causing it to sound 'loud'. A sound pressure level meter sorts things out pretty quickly. They are available as an app for smartphones.
My Dennis Had amp is an SEP (pentode) at from 12 to 17wpc depending on tubes used, which means with Gold Lion KT77s, my "tube du jour," I'm likely getting 10 to 12wpc. This drives my 99db Heresy IIIs to as loud as I need to hear 'em with plenty of headroom left. I cheat with a couple of REL subs, but man...a great sounding thing.
Thanks Ralph, having your MA-1's OTL's I agree that listening to higher levels without distortion it is an exceptional experience, I figured you were talking about your OTL's
The loudness cues to which I was referring are the higher ordered harmonics- the 5th and above. The human ear uses these harmonics to sense sound pressure. But it also assigns a tonality to any distortion- the higher orders cause brightness and harshness even in tiny amounts, since the ear has to be keenly sensitive to them in order to gauge sound pressure over a 130dB range.
If you know these facts then that gives you a good idea of how to approach amplifier design. Since the ear is arguably more sensitive to the higher ordered harmonics than **anything** else, it follows that for electronics to sound natural that is the kind of distortion that should be minimized (BTW it is this type of distortion that characterizes most solid state designs). When this is done, you can run much higher power levels and yet the system will not sound loud as all those loudness cues aren't being generated by the stereo.
The result is to naturally turn the volume up to get a realistic sound pressure. IMO, this is at the heart of the shortcomings of SETs, since they don't make much power and these harmonics are audible at any power level over about 20% of full power (which is why so many SETs are described as 'far more dynamic than their low power would suggest- its simply distortion that the ear interprets as loudness, showing up on transients that have the most power). The result is that even at relatively low sound pressure levels they sound loud. IMO/IME it is the mark of a good system that it always sound relaxed and never sounds loud until it really is (+95dB). The only way to get around this limitation with SETs is to use really high efficiency loudspeakers, which from what I've seen over the years doesn't happen that often- so many people are not experiencing the best that SETs have to offer.
Interesting thread, got resurrected after 10 years. If Ralph still follows it I would be interested on knowing which amps he was referring to in this comment
But the amps I use are designed to not generate any loudness cues to the human ear
I have a reasonably efficient speaker system (99 db/w) which I run with a variety of low-powered tube amps. Among such amps is an Audio Note Kageki, which is a 6.5 watt parallel single-ended amp running 2a3 output tubes. It is a pretty good sounding example of a SET amp, yet, I would not say it is the best amp for my system and taste. I generally prefer a pushpull 349a amp that I own that outputs 5.5 watts/channel. Both the Kageki and my 349a amp deliver an expansive and enveloping soundfield, rich pallet of harmonics and a natural presentation without edginess or overly "etched" detail. They differ a bit in the bass presentation. The 349a amp is punchier and tighter in the bass, but, that bass presentation is a bit "mechanical" sounding (a sameness regardless of source material) while the Kageki sounds more varied and natural (albeit soft sounding) in the attack of bass notes. Different strengths and weaknesses, and one is not "better" than the other.
Among the very best amps I've ever heard are a pushpull amp running the 252 tube and a one-of-a-kind output transformerless amp. Both made my Kageki sound anemic in direct comparison. While I really like several SET designs, I hardly think that, as a class, they outshine other tube designs.
IMHO, SET are most transparent, best in texture and tone, most organic and musical. They need sensitive speakers. But in any case, the sensitive speakers are MUST for any good, musical system. SET sound quality depends a lot from parts quality: tubes, transformers, capacitors, resistors,... So a good SET can’t be cheap to built. SET are best for acoustic music: classical, jazz, vocals. If you listen electronic music, POP, rock - there are better options than SET amps. I will never go back to transistor amplifiers and low/mid sensitivity speakers. Regards, Alex.
After years of SS amps (except for guitar amps....all tube) and just after a nice few years with a great sounding push-pull tube amp, I was absolutely floored by a little Dennis Had single ended pentode amp...just amazed at the clarity and detail, and what just seemed like musical accuracy. I'll never sell the thing, and with efficient speakers and a couple of powered subs, I'm done.
I have a system that includes a modded and fully tube-rolled 3-watt Moth s2A3 amp, Omega Grande 8R speakers, Von Schweikert subwoofer, tubed CDP, and all Jade wires. I also have a system that includes Mac 500-watt MC501 monoblocks, C2300 preamp, Marantz sa11s2, Montana EPS2 speakers and all Wireworld wires. I love the 2A3 system. The SS systems beats it in every parameter. Many roads to Dublin.
I went from high power high current to SET. I bought a 6 Moons reviewer sample amp(that he effused immensely about) and bought the speakers he recommended to go with it (which were also reviewed by him). Now this was not salary priced equipment, but reasonably priced and I was told would take me a good distance into SET performance (by the reviewer).
Sure it did some things well. I am not so sure I would say better than my high power system, but certainly differently. The SET set-up was a faction of the price and this should be noted. What it didn't do as well was significant to me.
My EXPERIENCE and opinion was that if you don't mind just listening to a portion of the music on the recording, albeit that portion sound nice, then you may very well like SET. However, if you feel that you need the entire frequency spectrum at decent or full weight, then you may end up disappointed - as I did. I am now moving back to higher power (at least vs. SET).
Will everyone eventually end up there? No way will that ever happen. It is definately a niche type area.
All that being said, I am confident that there are $100K SET systems that expand beyond my experiences.
Having used Wilson Audio speakers for a very long time I was always told you need big SS to drive them. Used ML 33h, 33, then the ASR Emitter II. Having been intrigued by all of the SET discussion here on Agon decided to get a Wyetech Topaz which is a SET using 211 output tubes. Never gonna work I was told. I much preferred the sound of the SET to the SS in my system. In turn I sold all of my two channel SS amps. The most recent loaner to me was the Bryston SST SQ 28 monos. In my system they did not work at all and returned them after a little over a week. So in my case I am happy with my SET. But that is not to say that the SS cannot sound right.
Back in the 'Sound Practices' day, I played with SE amps. 300B and 2A3. PP 6B4Gs too. Though pleasant sounding, I was forever trying to find a good speaker to match up with them. I tried different modern and vintage coaxials without success.
I eventually turned away from Triode SE and back into Ultralinear designs. The higher power worked better with my Altec 604 / Eminence speakers (ie - the UREI 813A). The best DIY design of mine was a SE EL156 UL with a pentode front end. Lots of power (~20Ws), fast, detailed but not clinical. This was nirvana for me.
Then I accidentally got a good deal on a Threshold S/500 amplifier. They gripped the UREI speakers better than any tube amp I have ever heard. No solid state glare or grain - and they have enough power to drive any speaker I would want.
So I sold my SE EL156 amps to a friend (where they are still churning away) and after twenty years of tube amps jumped on the solid state wagon. I'm not getting off either. Though lacking in some of the qualities that tube gear has, good solid-state also has it's own signature that appeals to me.
I had a few well revered ss amps (Rowland, Threshold,...) and auditioned many others (Levinson, Krell,...), but when I decided to go tube, without any auditioning, just out of curiosity from what I had read, like you, it was, in hindsight, one of the most revelatory experiences of my high-end audio journey. I was a convert from the first instrument, first voice and haven't looked back. I was in shock by just how real and natural the sound was and amazed that the bass actually trumped my ss amp. You always hear about how tube amps have no bass and that couldn't have been further from the truth. The bass from the tube amp was not only deeper, with more impact, it was also more musical, dynamic, tight, and fast. That last ss amp was the Rowland Model 10. Hard to believe a 15 watt hand made, point to point wired 572 Svetlana power tube monoblock amp embarrassed a 150wpc ss amp. But it did. And you'd think it'd have to for the price. It was the ViVa Verona Monoblocks. The ViVa absolutely demolished the Rowland in every which way. I had never heard music sound quite like that. Almost magical. The sound was nothing like I had heard before from ss. Now I knew what all the gushing talk over tube gear was about. After that I played around with some others (lower priced, both high and low power) and ended up with TRON Cantata 300B mono's, having had the TRON Jubilate monos just before that. I probably would have kept the ViVa had I decided to get more efficient speakers first instead of a more powerful tube amp (I had Kharma Ceramique 2.1's). Now I have 98dB Horning Agathon Ultimate speakers. Another revelation of sound and a design, like tubes, that makes most audiophiles skin crawl - horns. Again, nothing like I've heard before. I had Maggies for years and swore I'd never have traditional box cone driver speakers. But I kept an open ear and listened to one years back. That's all it took to hear that I was missing something. The horn speaker was as dramatic a transformation for speakers as tubes were with amps. It's hard to understand how some audiophiles have such an aversion to tube gear in general, and in some cases plain prejudicial, without even hearing one. But thats' how some people are. They don't like change. Having been a ss audiophile for more years then with tubes I have to think it's just tradition, like those who think audiophiles are nuts and that there's no difference in sound with the HiFi gear, or cables,..etc. I think they're just in denial because it's so different to what they're used to. They don't want to believe what they're hearing. It's not ss so it can't be good. Speaking from my experience though, I have never heard such musical realism except at a live performance.
IMO if there is a subsonic rolloff, you hear it as a diminution of bass impact. It can also be measured quite easily- square wave tilt is the measurement. Having played around with LF cutoff frequencies a lot (our amps are full power to either 1Hz or 2Hz), all I can say is its easy to hear once you know what you are looking for provided you have speakers with bandwidth into the low 20s.
I think he is talking about the missing fundamental effect. If the fundamental frequency is f, there will be harmonics at 2f, 3f, 4f, and so on. Even if your system can not produce the fundamental (as has been pointed out, the bass note on a piano goes as low as 27.5Hz), it can definitely produce the harmonics which is how you perceive the bass note. Your brain fills it in.
I can listen to piano on my iPod earphones which definitely don't go as low as 27.5Hz, but I can still "hear" bass notes on the piano.
There are products out there that take advantage of the missing fundamental effect by boosting the harmonics, giving the sensation of more bass.
hey Atmasphere...interesting. i have heard the argument for frequency extension on the upper end. what do you mean by "artifacts"? are these artifacts measured or only heard? please forgive me as I am not an engineer. i'm looking at a square waves and looks pretty good to me. thanks....
The cutoff frequency of the amp does play a role. Generally speaking, you can hear artifact associated with the cutoff (-3db point) at frequencies up to about 10 times the cutoff frequency. So if the amp starts to roll off at 20Hz, you can hear artifacts up to 200Hz.
The same is true of the HF rolloff- except that now its 1/10th the cutoff frequency. So if the amp rolls off at 20KHz, you will hear artifacts down to 2000Hz.
This is why designers try so hard to get bandwidth!
HanaleiMike, take a visit over to the JE Labs website. Question...do you listen to acoustic instruments or a lot of electronic instruments? For the latter, some other kind of amp/speaker combo might be better.
My 300B amp measures flat well below 30hz. 30hz is the lowest range of piano. They also measure beyond the upper limits of my hearing capability. I need to measure my 45 amp (have much smaller, cheaper transformers) and haven't done so yet. I cannot listen to the 45 amp wide open but can listen at a decent level...too much distortion and I'm guessing it is what Atmasphere describes. In another forum JohnK told me minimum 300B for my speakers and he was right...for optimum performance. Thanks JohnK.
Speakers are 100db at one meter. I think I have roughly somewhere between two to four watts to play with before the distortion really starts to kick in and become relevant. Four watts is 106db. I would be inclined to agree with Atmasphere on how much power is required for these sorts of amps. This for live music type levels not quiet listening.
However, this should be more about enjoying the music/sound (overall frequency response throughout the music spectrum) based on how you listen and not getting caught up with the manufacturers' spec chasing of lower and upper bandwidth statistics.
Perhaps a bigger reason SETs are popular is price/performance ratio. Nothing comes close imho.
My experience with SET was after several years of experimentation with SS and PP amps matched with a number of speakers. Most recently a few more systems have made their way through, and while some were quite good, I am always in a hurry to get my 300B SET/Altec 604 back on for the ease and sense of 'life' it conveys.
I have been very happy with my present main system for the last three years. The lower freq are augmented by two powered subs that have been set on a seperate volume and balance control to allow ease of integration with the mains. Further the two subs have varying crossover points to fill in any gaps. Not complicated in practice, but it took me a while to get it to this level.
Along with the well considered responses above. I'd like to add that the realism from this current system is quite stunning at times. Tho I'll be the first to admit the speakers could have better resolution, amongst other things... The whole effect as a whole is wonderful.
I went the other way - from a Cary CAD-805AE SET to the CAD-211AE push-pull amps. The reason for the switch was because the SET was underpowered for my new speakers. With the old speakers (ProAc D38's) the SET sounded magnificent with certain types of music - vocals, lieder, violin solos, string quartets. But the SET's could sound muddled when given something a bit more full range, like heavy orchestral. The symptoms were poor seperation of any instrument from the midbass down.
The CAD-211AE is an improvement in almost every aspect, mostly with dynamics, midrange weight, and almost unstoppable drive. But the top end is nowhere near as good as the SET. I was bi-amping for a while (see my sig) before I was forced to return the SET to pay the bills! If I could afford it, I would buy another pair of CAD-805's and bi-amp again.
Johnk, the post was worded right. The upper power limits of SETs in a way are more of a function of the output transformer that it is the tube! The bigger you make the transformer, IOW to handle more power, the less bandwidth it will have. If you try to optimize it for bass, the highs will be rolled off and vice versa.
Since many high efficiency speakers (99db+) have limited bass response, SET builders usually sacrifice the bass performance in favor of the highs, since speakers that go below 40 Hz in the high efficiency world are few and far between.
IME experience the bigger SETs also have less detail. This is based on my personal listening experiences, but you will notice that one of the revered 'king' tubes in the SET world is the type 45, which usually makes less than one watt at full power. IOW, the smaller you make them, the better they sound, which is a common theme with amps in general (although OTLs seem to be one of the few exceptions), both SET and P-P.
I've also noticed that it is exceedingly rare to compare like technologies in the SET world. People often compare say a 300b SET against a P-P EL-34 amp (with the results in favor of the SET), but how often is a 300b or other SET compared to a P-P DHT class A amp of the same power rating? IOW to be scientific, this is where one would start if looking for real answers.
Atmasphere you said {This power limitation is one reason why I don't use SETs. The bigger you make them, the less bandwidth and detail} Please explain if you would for this doesnt seem to make sence, maybe its just wordered wrong. Maybe Im not getting your point. But power rating in SET doesnt have anything at all to do with bandwidth its the SETs design. Mostly the transformers used. I have owned SETs with limited bandwidth but if of proper build this isnt a universal SET problem. Now if you dont have power your loudspeaker requires thats a system matching error and not the fault of the SET amp but of owners system choice.
Breuninger, it was really cool to read your thoughts on this subject. I know you come from a place of experience and I've slowly been coming around to share your opinion.
Hearing you say that stuff makes me feel like less of a traitor for coming back to push-pull and solid-state amps on speakers that dip below 6 ohms and are less than 88db sensitive. Haha.
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