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  1. #1
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    Sophia Electric Baby Amp

    A couple of nights ago I got to listen to the Sophia Electric Baby Amp. I had never heard an SET amp before and I was beguiled at the SQ from that little thing. My buddy is using the Sophia as part of a desktop computer system with Klipsch 3.1 speakers.

    Here is a link to a review of the amp that I generally agree with the reviewers findings:
    sophia

    What I am scratching my head over is that I did not find the amp to sound aggressive or tilted to the high frequency as other reviewers have consistently remarked.. I thought it was just right-- balanced in the whole presentation.

    Being that I am new to the whole tube electronics thing I am trying to understand the differences between SET and other tubed gear. My question is this....is the only difference in SET the type of tube that is used, a triode?

    Thanks for the feedback fellas!

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    > A couple of nights ago I got to listen to the Sophia Electric Baby Amp.
    > I had never heard an SET amp before

    And you still might not have heard a SET amp.
    The Sophia Electric Baby Amp, according to the link you provided, is described as a push-pull amplifier using pentodes.

    BTW
    The acronym SET is for single-ended triode.
    Sophia uses the abbreviation S.E.T. for "Sophia Electric Technology", and is trade marked.
    The Baby Amp is marketed as S.E.T., rather than SET. IMO this is potentially misleading, akin to "LED" TVs.

    > .is the only difference in SET the type of tube that is used, a triode?

    The two salient attributes of SET:
    * triode power tube
    * only one tap of the output transformer's primary is connected to the power tube (i.e. no center tap).

    In their minimal configurations, a single-ended amp uses one power tube (per channel), whereas a push-pull amp uses two power tubes (or dual elements in a common tube envelope). Counting output tubes is not a reliable method of distinguishing between single-ended versus push-pull. The output transformer(s) should be examined. The primary of a single-ended output xfmr has only two connections (or taps), whereas the primary on a push-pull output xfmr has three connections.

    Some say that the best compromise for sound and power is push-pull triodes.

    Regards
    Last edited by blue_z; 01-13-2012 at 02:16 PM.

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    blue_Z, thanks for your excellent reply. I appreciate you sharing your knowledge and clear explanations.

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    The Single Ended Triode is the simplest of all amp circuits and uses the least number of parts. The SET is one of the oldest amp designs dating back to the 1920's. Unlike most push pull tube amps SET's require no negative feedback. Negative feedback is used to lower distortion specs. Feedback creates time smear which results in two dimensional sound.

    Since SET's only make a few watts one must have high efficiency speakers to benefit from their high detail and holographic magic. SET's aren't well known or popular as commercial speaker companies are inclined to produce low efficiency speakers with power robbing crossovers that can command higher price tags and require lots of wattage. Companies that make amps cotton to the demand for higher power amps to drive these inefficient speakers as these big amps can increase profits vs a simple flea amp SET.

    The Chinese made Sophia is a push pull amp and sells under other names on ebay for a couple of hundred.

  5. #5
    RGA
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    SET amps typically run into problems with difficult to drive speakers - many reviewers unfortunately will blame the amp as "sounding that way" when it is simply running into power capability issues. When pushed to hard the amp will compress and the bass becomes wooly and the treble rolled off (hence the tilted frequency extremes comments).

    If you use quality speakers that can take advantage of SETs they won't distort they won't run into power issues.

    SET isn't the only kind of amp that sounds good - and IME it takes a fair bit of coin to do it any real justice because it is so dependent on the quality of the transformers and few are out there make top quality ones.

    Like many things in life the KISS method works best - Keep It Simple Stupid. A high quality SET amplifier is the simplest design and it sounds terrific - IME done right it has no equal. The rest add and add and add more garbage that gets in the way - rather than use high quality parts they use off the shelf cheap parts that get in the way of the original sound.

    SS amps use Feedback is which is an error correction device but the amp itself is creating the errors that SET amps don't create. The ill-logic of it is mind boggling.

    The big problem is that SE tube amps should sound like giant distortion generators - they should sound bloody TERRIBLE. The fact that they sound so vastly better - clearer, better bass, open extended no fatiguing etchy highs and yet the measured response is WORSE - then there is a serious problem with the measurements (probably created by marketing departments and blindly followed. The result or truth happens when the play button is pushed.

    Peter Qvortrup (CEO Audio Note - arguably the top or right there maker of SET amplifiers in the world) explains in Layperson lingo starting at about 3 minutes in. Hyundai might have Stolen Toyota Corporate "Secrets" - Motor Trend The General Forum Forum

  6. #6
    Shostakovich fan Feanor's Avatar
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    Quote Originally Posted by RGA View Post
    ...
    The big problem is that SE tube amps should sound like giant distortion generators - they should sound bloody TERRIBLE. The fact that they sound so vastly better - clearer, better bass, open extended no fatiguing etchy highs and yet the measured response is WORSE - then there is a serious problem with the measurements (probably created by marketing departments and blindly followed. The result or truth happens when the play button is pushed.
    ...
    You and I can agree that we don't have a definitive set of measurements that will define good sound. No amp is perfect -- if any were, presumably there would be no issue, right? So the objective ought to be which shortcomings are the least offensive and how to build an amp that has the least offensive shortcomings.

    The anti-S/S argument goes that the necessary negative feedback produces a type (or types) of distortion that, while low, are psycho-acoustically very objectionable. These distortions are usually identified as high-order harmonic distortion and/or intermodular distortion.

    The anti-tube argument goes that tubes typically produce relative large amounts of low-order harmonic distortion, and that while this low-order h/d is psycho-acoustically pleasant, it works against accurate, genuinely realist sound.

    For one thing, I think it's dangerous to generalize. Audiophiles privileged to own quality, high-end equipment talk about "convergence" of tube and solid state designs, i.e. as the quality (and price) go up, the sound becomes more alike. Apparently this is because offending distortion in both cases can be mitigated with careful, thorough design and implementation.

    The other big thing is personal preference. (And I think this comes into play in the case of lower- and middle-range equipment.) Do you want relatively more accuracy at the price of some edginess, or do you want smoothness and warm at the expense of accuracy?

    For my part, I guess I favour the accuracy. Partly it's the type of music I listen to, (acoustic; Classical); partly maybe it's my ears, (I'm deaf above 10 kHz); partly it's just my taste.

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    Anyone who spends time with a single ended triode can hear the difference and it's not subtle.

  8. #8
    Ajani
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    Quote Originally Posted by Poultrygeist View Post
    Anyone who spends time with a single ended triode can hear the difference and it's not subtle.
    Probably. But that doesn't mean they prefer the SET sound. There is no HiFi product or technology that is universally loved.

  9. #9
    Ajani
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    Quote Originally Posted by Feanor View Post
    You and I can agree that we don't have a definitive set of measurements that will define good sound. No amp is perfect -- if any were, presumably there would be no issue, right? So the objective ought to be which shortcomings are the least offensive and how to build an amp that has the least offensive shortcomings.

    The anti-S/S argument goes that the necessary negative feedback produces a type (or types) of distortion that, while low, are psycho-acoustically very objectionable. These distortions are usually identified as high-order harmonic distortion and/or intermodular distortion.

    The anti-tube argument goes that tubes typically produce relative large amounts of low-order harmonic distortion, and that while this low-order h/d is psycho-acoustically pleasant, it works against accurate, genuinely realist sound.

    For one thing, I think it's dangerous to generalize. Audiophiles privileged to own quality, high-end equipment talk about "convergence" of tube and solid state designs, i.e. as the quality (and price) go up, the sound becomes more alike. Apparently this is because offending distortion in both cases can be mitigated with careful, thorough design and implementation.

    The other big thing is personal preference. (And I think this comes into play in the case of lower- and middle-range equipment.) Do you want relatively more accuracy at the price of some edginess, or do you want smoothness and warm at the expense of accuracy?

    For my part, I guess I favour the accuracy. Partly it's the type of music I listen to, (acoustic; Classical); partly maybe it's my ears, (I'm deaf above 10 kHz); partly it's just my taste.


    I think personal preference (and the opportunity to experience different technologies) is the key to audiophile choices.

    Even the definition of accuracy in relation to HiFi can come down to personal preference. Which is more accurate: A speaker with a wild frequency response curve but good timbre or a speaker with only fair timbre but a flat frequency response? So at the end of the day it comes down to minimizing the compromises to develop a product at a price point.

    I think a lot (possibly even most) audiophiles make the mistake of assuming that their personal preference is the RIGHT way. Hence anyone else with a different opinion is brainwashed, deaf or corrupt.

  10. #10
    RGA
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    Feanor - but you have to consider where the distortion resides - in a SET it ONLY resides at high level when the amp is pushed hard - it is NOT THERE at low level. You can get around the amp power via speaker efficiency. You can't get around it with SS because it is ALWAYS there no matter what volume level. And it is why SO MANY people always yammer about needing more and more power - because they have to CRANK IT UP to make things out clearly and why so many systems are deemed to sound better louder. WIth SS based gear I am always wanting to reach for the volume knob to bring it to life. It is a reason that virtually all SET owners rave and rave about transient attack. It's faster and cleaner sounding.

    Distortion means the sound should be AUDIBLY distorted no? It should not be able to pick and choose what part is distorted - it should ALL be distorted.

    That means the voice should literally warble, the bass should be flabby, the treble should sound fuzzy or lacking sparkle. It should sound thick - the midrange should be overshadowed by the bass line because the woofer is not being driven properly. And yet that is not the case - it is the case when and ONLY when the amp is running beyond it's capability. And in a SS amp you know when that happens because the sound is truly atrocious but in a SET amp you can't quite tell because it never sounds bad the same way a SS sounds bad. It sounds mushy and compressed - but I have, to be blunt, excellent hearing and I know when something sounds veiled or wishy washy - and I HATE THAT. I hate it less than SS clipping but mud is mud.

    And virtually all SET owners are classical music lovers. I am one of the very very very very very rare SE tube owners that is not "exclusively" a classical music listener. Art Dudley is probably THE classical music listener at Stereophile. Constanine Soo at dagogo is a huge classical music guy. Enjoythemusic - they go one better - the reviewer there who owns a complete AN SET system reviews classical music for a living and is also a classical music composer who is actually played. So if the guy composing and conducting at the Philharmonic doesn't know what it's supposed to sound like no one does!

    Mike and Nelli of audiofederation who also sell Soundlabs which is arguably the TOP panel maker for sound quality listen mostly to classical music and play it at shows. Peter Q is a classical first guy with one of the best collections in the world on both CD and LP formats. He is a founding member of an organization that gives scholarships to classical musicians and is also a judge because no one knows as much as he does about classical music.

    The vast majority of people on boards under 50 started out with SS amps - the ones who go to SET usually don't go back - and pointing to the one guy here or there is not convincing - the overwhelming majority of them don't go back and it has nothing to do with preferring distortion characteristics - distortion doesn't explain why it sounds faster clearer crisper. There is nothing warm about Audio Note gear (it can be depending on the recording but there is a reason why in every review the word Transparency is a big key) I probably own the warmest and most veiled amp that they make. Partly because if I have to choose a slight stray from accuracy I'll take that than the fatigue inducement of most that sound bright which passes for accuracy and good ears know the difference between bright and accurate - most however think if it's brighter it must be more accurate. Which is what they bank on during the 10 minute auditions most people give them on the wall-o-amps board at the big chains - the amp that stands out must be better - same for speakers.

    The convergence argument I sort of agree with but I would not really parrot things on forums without first hand experience. I want to read the specific SS amp to the specific SET amp. And in fact I never read anyone use specifics when they make those comments. It's about as dumb as posters who say they can make a SS sound like a SET by putting a resister in the chain - the people who have never once auditioned a SET amp. SET amps don't all sound alike so how you can put a resister in a speaker chain and make it sound like two different sounding amps is the height of ill logic.

    There is a reason I always use this forum review of the guy who owned SS and owned top of the line Bryston and PMC and decided to bring home a much less expensive AN system. Why do I bring it up? Simple because Bryston is about as Solid State sounding as solid state gets. It's all about accuracy (ahem) and PMC is a professional grade monitoring company(hey that's what PMC stands for after all) that makes studio speakers and active monitors. This guy had the best of both.

    So he had the day to day listening of the supposed "supremely accurate" sound. Added in a Meridian which are the "best of the best" of the CD digital replay world (ahem). So you could safely say that this guy arguably had about as accurate a system as you could get from SS amplifiers and any boxed speaker can get.

    I have heard the same combinations for decades as well. He isn't responding to warbly sound. He's responding to the fact that he hears proper time domain behavior, the fact that he can more of what is on the recordings because it isn't being looped internally a milllion times, and he's hearing clarity and each instrument as separate entities in space and he's hearing the wholeness of notes not a gritty minced meat compressed back together chicken McNugget version of prime breast meat.

    His analogy is bang on perfect flourescent light irritation versus natural light reality. And even if you can't hear above 10khz it's very readily apparent if you have the speakers that won't give the amp fits. General Asylum: REVIEW: Audio Note Level 3 system Other by KevinF

  11. #11
    RGA
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    Quote Originally Posted by Ajani View Post


    I think personal preference (and the opportunity to experience different technologies) is the key to audiophile choices.

    Even the definition of accuracy in relation to HiFi can come down to personal preference. Which is more accurate: A speaker with a wild frequency response curve but good timbre or a speaker with only fair timbre but a flat frequency response? So at the end of the day it comes down to minimizing the compromises to develop a product at a price point.

    I think a lot (possibly even most) audiophiles make the mistake of assuming that their personal preference is the RIGHT way. Hence anyone else with a different opinion is brainwashed, deaf or corrupt.
    Yes but that only applies to people who have actually bothered to listen to said technology. Most people hear SS all their lives - audiophiles in my general age group grew up on SS - most hi-fi stores in Canada carry only SS amplifiers. And that is likely true in the U.S. There are a few that will carry tubes like ARC or McIntosh but even here both of them sell SS amps.

    How many people actually audition Tube amps? The number is greatly reduced. Tube hybrids don't count cause you don't know if the problem (if there is one) is generated from a mismatch in the technologies so it can hardly be blamed on the tube cd player or preamp - the fact that it wasn't there with a SS preamp or CD player isn't really deductive reasoning.

    The fact is very few people audition tube amps - and very very few audition SET amps - and then which SET amps? There are may different types of them - some people don't like all that much.

    The problem is most people who spout off on SETs have never ever heard one - and then even if they heard one - so what - It's like me saying I heard a Yamaha receiver so now I can OPINE on Monarchy and Pass Labs - because after all "I heard a solid state amp) or I auditioned a $100 DAC so I know what all DACs including the Benchmark Dacs sound like.

    Listening to a Cary is not the same as listening to an Audio Note just as listening to a Copland is not the same a Mcintosh or ARC.

    Indeed, I should try and refrain from lumping SS together - because it's not all the same. I am reviewing a $2k Roksan SS amp and I own $2kish Rotel system and they don't sound at all alike.

  12. #12
    RGA
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    For some reason I can't edit my earlier post - anyway the link was wrong to the way negative feedback works - 3 minutes in with Peter Q explaining why feedback and the resulting THD measurement is misleading to make the spec look good but has no bearing on the truth (err completely 100% worthless). Peter Qvortrup @ Hi-Files Show 2009 (part 2) - YouTube

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    Shostakovich fan Feanor's Avatar
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    Richard, because you have responded at such length, I feel obliged to respond.

    I don't see myself ever owning a SET amp, although of course one never knows. I'm very content with my Magneplanar speakers and I don't see myself going to a high-efficiency design necessary to match a SET. (If I tried to used a SET with the Maggies I'd get sound but it would be clipping a lot of the time.) It would be fun and instructive to live with a tube amp for a while, but I don't it could be a SET but instead some sort of push-pull or "ultralinear" design capable of 50-60 wpc or better

    Whatever you say about the relative virtues of S/S vs. tube and esp. SET -- and whatever the truth of those assertions might be -- I don't have a universal problem with S/S sound such as you suggest exists. My current Class D Audio SDS-258 amp is the most transparent amp that I've own; (its near equal was another class D amp, a Bel Canto eVo2). If you argue that s/s veils the sound, then you are 'way off the mark. Granted, my current class d amp isn't "warm" sounding nor, (though the terminology is vague), does it have the "harmonic richness" that tube amps in general are said to deliver. However it does deliver instrument timbres more accurately than any amp I've owned.

    Amps I've owned, BTW, include the Monarchy SM-70 Pro, an S/S amp but one well regarded by the pundits. It is a high-biased, zero global feedback design does, (according to the pundits and me), deliver some measure of that so-called "harmonic richness" associated with tubes. To my ear, the Monarchys are inferior to my Class D Audio amp in general and specifically in transparency and timbre rendition.

    The Class D Audio SDS-258 driving my Magneplanars deliver impeccable sound to my ear. So much so I have no specific desire for improvement -- I find it hard to image even. This is playing my best recordings as judged by overall merit, including some hi-rez recordings. With my poorer recordings it is another matter: these can sound bright, edgy, and/or veiled, but the fact that the best sound great demonstrates that these deficiencies are on the recording, not being added by the amp

    Something interesting is that when I went from the Bel Canto to the Monarchys, I felt that the Monarchys sounded better playing about 70% (not all) of my recordings. By curious coincidence, when I went from the Monarchys to the Class D Audio, again I felt the new amp sounded better than the old amp for about 70% of recordings. But what was the stand-out difference in these impressions? In the Bel Canto to Monarchy case, the 70% comprised my less-good recordings, whereas in the Monarchy to CDA case the 70% comprised my best recordings.

    But let me speak of preference. I value transparency and timbrel accuracy about warm & smoothness -- this won't be everybody's choice. Finally I'll also make the point that records vary in quality and that recording practice leaves something to be desired. Too often recordings end up sounding too bright; I suppose this reflects the producers & engineers objectives and/or preference. (BTW, this goes for vinyl as well as digital recordings.) For my part, I choose to hear recordings the way the creators them: I don't expect or want my amp to "correct" their work.

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    It's common to read of folks who progress from SS to push pull tube amps and then on to SET's but I've never heard of anyone who ever gave up SET's for SS.

    My $2500 SS Classe CAP-150 was totally embarrassed by my $250 Miniwatt SET while my $350 Bottlehead 2a3 SET is way better than my Miniwatt. If you haven't heard a good SET ( and I haven't heard a bad one ) I would think it impossible to have an educated opinion or say it's a matter of preference. The difference is not even close.

  15. #15
    Shostakovich fan Feanor's Avatar
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    Quote Originally Posted by Poultrygeist View Post
    It's common to read of folks who progress from SS to push pull tube amps and then on to SET's but I've never heard of anyone who ever gave up SET's for SS.

    My $2500 SS Classe CAP-150 was totally embarrassed by my $250 Miniwatt SET while my $350 Bottlehead 2a3 SET is way better than my Miniwatt. If you haven't heard a good SET ( and I haven't heard a bad one ) I would think it impossible to have an educated opinion or say it's a matter of preference. The difference is not even close.
    Ship me your Bottlehead so I can try it out, PG. If I like it, I'll buy it from you and reimburse the shipping.

    BTW, I don't doubt that the Classé and SETs sound different.

  16. #16
    Ajani
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    Quote Originally Posted by Poultrygeist View Post
    It's common to read of folks who progress from SS to push pull tube amps and then on to SET's but I've never heard of anyone who ever gave up SET's for SS.
    That means far less than SET lovers think. As you know, SS is widely available while SET is rare. Hence, someone who owns a SET has likely owned/auditioned many SS amps before moving to SET (as both you and RGA did). So why would you switch back? Clearly you both preferred SET when you tried it.

    Someone who auditions SET and doesn't like it, simply won't buy it.

    Quote Originally Posted by Poultrygeist View Post
    My $2500 SS Classe CAP-150 was totally embarrassed by my $250 Miniwatt SET while my $350 Bottlehead 2a3 SET is way better than my Miniwatt. If you haven't heard a good SET ( and I haven't heard a bad one ) I would think it impossible to have an educated opinion or say it's a matter of preference. The difference is not even close.
    Here's the problem with that logic. Having never heard a SET I can't say whether I'd prefer the sound to SS or not. However I can say that it is a matter of preference. Why? Because enough experienced audiophiles have tried SET and still prefer their SS gear. So clearly not everyone loves it.

    I've heard the same kind of over the top claims about dipoles. Yet I've not been impressed enough by any of the ones I've heard to want to ditch all "monkey coffins".

    I certainly intend to audition a SET/HE combo, and I think bottlehead or decware are prime candidates for SET amps.

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    Fenor,

    I couldn't go a day without my 2a3 Paramours much less sell them.

    OK. I'd like to invite my new friend DJ ( the golden eared Charlotte Philharmonic violinist ) who is a recent convert to SET to chime in here and posts his thoughts.

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    Hey P.G.

    Quote Originally Posted by Poultrygeist View Post
    The Single Ended Triode is the simplest of all amp circuits and uses the least number of parts. The SET is one of the oldest amp designs dating back to the 1920's. Unlike most push pull tube amps SET's require no negative feedback. Negative feedback is used to lower distortion specs. Feedback creates time smear which results in two dimensional sound.

    Since SET's only make a few watts one must have high efficiency speakers to benefit from their high detail and holographic magic. SET's aren't well known or popular as commercial speaker companies are inclined to produce low efficiency speakers with power robbing crossovers that can command higher price tags and require lots of wattage. Companies that make amps cotton to the demand for higher power amps to drive these inefficient speakers as these big amps can increase profits vs a simple flea amp SET.

    The Chinese made Sophia is a push pull amp and sells under other names on ebay for a couple of hundred.
    Thanks for the info on the Sophia alternatives and the SET background. So, what speakers are you using with your SET amp?

  19. #19
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    Quote Originally Posted by Poultrygeist View Post
    Fenor,

    I couldn't go a day without my 2a3 Paramours much less sell them.

    OK. I'd like to invite my new friend DJ ( the golden eared Charlotte Philharmonic violinist ) who is a recent convert to SET to chime in here and posts his thoughts.
    ...I graduated to SET from variety of SS amps in my past. I owned a ton (literally) of sound equipment - Adcom, Crown, QSC, Pioneer (the C/M stuff, Elites). I worked as FOH sound engineer, recording studio so I am familiar with most of high end pro equipment as well. I worked as a club DJ in NYC...lots of bad equipment there...

    I am also a professional musician and an electronics DIY'er.

    In my quest for "musical" hi-fi I auditioned a lot of amp-speaker combos, some in very high dollar range, tubes and OB/single driver speakers were never on my list - they were largely unknown to me. Harman doesn't want you to buy them, it just doesn't fit into megawatts marketing.

    I was looking for the ultimate refinement in sound quality that would please my ears. I started auditioning Tekton, Zu, Omega speakers that were driven by those weird looking tube amps.

    So here I am. I have sold all my SS gear and all the high power "full range" speakers. All my systems are SET amp based, driving full range single driver or open baffle speakers. My ears couldn't be happier.

    Recently I brought my MiniWatt - Tekton 6.5 combo to a week-long symphony orchestra gig and let my friends listen to it. They didn't know squat about tubes or Fostex drivers, but their mouths were hanging open while listening to the music (spotify, via iPhone!). I demonstrated how the same music sounds with SS amp (I had small JVC amp). One of my colleagues was so impressed with the combo that he bought the speakers from me and wrote the names of amps that I recommended (I didn't sell my MW to him). He said that he never heard SUCH sound before.

    We are talking professional musicians here with ears that feed their families. One audition was enough to make them fall in love with tube sound through high efficiency single driver speaker.

    Now, SET amp was my first tube amp. I tried other amps but always came back to SET, zero feedback design. My next step is to find a SET OTL amp to audition...

    Even order harmonics of SET amp are the same harmonics that are produced by acoustic instruments (string and woodwinds especially). That may be the reason why SET amps are described as being "musical", they mimic the properties of musical instruments themselves. Even order harmonic distortion could be described as "overtones", and these musical overtones is exactly the thing that makes music sound rich and alive, they are non-fatiguing (as opposed to odd order harmonics of SS, push-pull, GNF designs). Violin sound is full of harmonic "distortion" (all even order). Anybody comparing electric violin with acoustic violin will be able to tell the difference, even though the strings and the pitch played are the same.

    Bit of theory: the second order harmonic of first octave A (440 hz) is 880hz, which is the same A but an octave higher, therefore is not perceptible as "distortion" because it is in unison with the original tone. Same goes for 4th, 6th, 8th....order harmonics.
    Last edited by djdonis; 01-16-2012 at 07:46 PM.

  20. #20
    RGA
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    Ajani and Feanor

    You both raise some points here.

    1) just to let it be known - I don't own a SET - I own a SEP - there is a difference so while I love the sound of SET it's not because I am raving about what I own - cause my amp isn't one. So I am perhaps less biased on the matter being a non owner - I, in fact own and have owned more SS amps (still do).

    2) The issue of preference will always be at play because there are a few schools of thought. Source first to speakers and the other buy the speakers first and worry about power later. I think the second is fundamentally the wrong idea and the former assuming the speakers are not a total travesty is better. And yes I know that speaker impart the largest amount of frequency variation and the largest amount of distortion etc.

    A speaker can't fix a bad source. No matter what you spend if you feed it crap you will get crap. There are probably many fine loudspeakers in and of themselves but if the best amps are 10 watts and under sets (and let's assume for the discussion this is true) and your speaker needs 200 watts of power where no SET amp operates then you are reduced to feeding a lesser signal. And good speakers will tell you real fast that the amps are not very good. And IME the people who seem to sell and trade gear the fastest are the people with SS and LE speakers because they're never really happy with it. So they spend lots of money on room treatments, equalizers, fiddle with trying to measure the speakers response curves, buy other little gadgets to stick on the speakers (like those pucks) or they buy wire lifters, expensive power cords, change their wall-sockets, buy expensive platforms to put under the equipment.

    They do all these bloody things because "something isn't right" but they never look the big box expenditure (the amp and speakers). They have lots of opinions on SET sound without ever hearing it which is also puzzling to me.

    Consider that Audio Note for example uses the hotel room furniture or simply put the gear on the floor - no wire lifters, no pucks, never need room treatment or equalizers or for that matter fancy power cords or power conditioners - cause they don't need all that BS. It's all used to FIX the gear that should not need fixing in the first place - and that applies to all the mods - Speaker X is only marginal until you send it to Bob's house of modding to make the speaker actually sound decent. WTF?

    Take the issue of Magnepan - here is a speaker that Magnepan themselves state on their main website page that they use a 40 watt receiver - that is ALL THE POWER THIS SPEAKER REQUIRES - PERIOD.

    Magnepans have terrifically even impedance they don't dip or doodle or do other nasty things. They're not overly high in sensitivity but sensitivity is somewhat misleading with dipole speakers due to their radiation pattern (ie they sound louder than the sensitivity spec would indicate). Apogee is different they have nightmarish loads.

    But here is the thing SET amps have a 4 ohm tap. You simply plug the speakers into the 4 ohm tap. They're a benign load - better than most boxed speakers claiming 90db. You can't go with just the sensitivity numbers.

    Soundhounds carries a very diverse line-up of speakers that most would agree with. Audio Note, Harbeth, Dynaudio, Sonus Faber, B&W, Paradigm, Cerwin Vega, Quad, Magnepan, Reference 3a, Meridian. And they carry a number of SS and tube amps. Wyatech Labs they had connected to a B&W N801 - the amp is 11 watts of SET power and yes you can't play this loud - you just can't and ultimately because of that it's not worth the money since you'd be paying $20,000 and IMO you have to be able to play loud for that outlay. Still - by far that is the best sound that that speaker has made in the 15 years or so I have been listening to that loudspeaker - and it's a reason why the guys at Soundhounds had it hooked up.

    Going back to Magnepan - 40 watts is the receiver Magnepan is using - the Audio Note Soro is 18 watts although AN amps are typically noted as being very powerful SET amps compared to the competition - it simply has more grip and "balls" than others likely because of the transformers so while the watts are not high the control the woofers is. 300B tube types tend to be a little mushier sounding but the 211 are certainly not. But just going by watts 40 watts over 18 watts is the difference of 3db and only at maximum level. Double the watts is a 3db gain in level - and most people note tubes usually have a perceived tripling of their watt rating (ie they sound like SS at three times the power).

    Moricab who owns top flight Apogees and used o have behemouth SS now owns SET amps - and Apogee is FAR FAR harder to drive than Magnepan or Quad or Soundlabs or Kings etc.

    The thing people forget with SET (at least Audio Note set but may apply to others I simply don't know) is that they are infinite load stable. In a very real sense SET is the most powerful amplifier design. Infinite load stable means that it can drive ANY impedance and a dead short represents infinitely low impedance. An AN SET amp has no fuse to blow because the amp can't be blow. If your amp has a fuse then it can't handle low impedance loads. Take a top of the line Krell remove the fuse protector - put a screwdriver across the speaker outputs and play some music - the amp will burn explode and never work again. That is dead short low impedance. An AN SET will run 24/7 for years doing the same thing.

    Certainly if you have your heart set on a 5 way speaker design that is 6 feet high with a bunch of crossovers and a bunch of long throw woofers then SET is not really an option. I question all of these speakers though because the good ones (and there are good ones) cost a lot of money and I'm not sure what their advantages are? None of them sound as coherent as a single driver in the midrange whether it is a Teresonic or an ESL or anything around the various Lowthers and the like on the market.

    All of the ones I've seen are very easy to drive. The big speaker has the advantage of bass and treble extension which is true but to get the box from being irritating or gaining quality midrange behavior is now up into the Acoustic Zen Crescendo, Usher Be 10 and Sony's flagship speaker price range - $12k and up and they're still not as good as a Teresonic for $10k in the midrange.

    The alternate option in the two way standmount but to be perfectly blunt none of them have the bass depth or weight or dynamic ability especially at loud levels to really truly deeply satisfy. I am generally not a fan of the small standmounts because while they offer some advantages over their big floorstander brothers they still don't compete with a single driver for coherency and it's not like they're bring any bass to the table as a trade-off - in fact many of them sound muddy and thick because they try to put out too much bass to impress "see how good the bass is" and it thickens up the midrange - which is why I am not a Dynaudio fan - it sounds lumpy no matter what amp is used no matter how much power is used.

    Big Standmounts like the AN J/E and Trenner and Freidle are quite large. The first two stuck in a corner has the intended effect of using the drivers as a mouth and in a sense makes the entire wall part of the speaker cabinet. It's no small wonder that Peter Qvortrup's favorite loudspeaker of all time is a single driver loudspeaker in a truly massive cabinet. What most audiophiles want I suspect is all of the coherence of the single driver speaker but they also want it "full range" and they want it not sound ear bleedingly edgy or hissy or boxy.

    The other problem is the amp - with SET very few people own speakers that are firendly to SET - not all horns are friendly to SET - the LS3/5a is very friendly to SET amps despite an 82db sensitivity rating - it's dead easy in terms of impedance - in fact it's easier to drive than the AN E/Spe HE at ~97db. The Maggie is 4ohm load stable -the AN E dips to 3.6ohms for a significant duration in the low frequencies.

    I even managed to play Lady Gaga on the 1.7 which while compressed does have some bass and I played it quite loud with the SORO with no problems - I could have easily turned the dial and played it at least two or three times louder again but the speakers were at a dealer and I don't want to damage anything - but they did say play at as loud as you like. It's the first time I have truly walked away from a Magnepan thinking "that sounded truly good."

    Lastly, Peter Q is a classical music guru has been to every major opera house in the world - he listens to it all the time live. But when SS guys were creating the myth that SET doesn't have any power he began bringing Heavy Metal to show - and well recorded heavy metal from the likes of Slipknot. Helps when you have teenager kids to help out. But this is why I laugh when I hear guys like Sander Sound's owner claiming you need 1000 SS watts to get proper dynamics. 10 rooms down the hall is Audio Note running a 20 Watt SET that completely and totally and utterly annihilated them in every conceivable way.

    I simply can't accept the notion that it's all opinion because there is no other way to hear it. Something either crushes a room with sound pressure level putting the feeling bass into the room with lighting fast grip and attack and real decay or it doesn't. And hell the AN E /HE doesn't even rank as a HE speaker according to the fanboys on AA. So if a 20 watt SET can do that with a speaker not even regarded as HE then you'll poop your pants driving an old Altec Voice of the Theater.
    Last edited by RGA; 01-17-2012 at 12:42 AM.

  21. #21
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    Thanks DJ for giving us your take. With RGA and now DJ I no longer feel like the lone standard bearer for single ended triodes.

    LeRoy,

    My full range primary system is a simple-to-build DIY consisting of open baffle 8" Tang Band W8-1808 with super tweeter over Eminence Alpha-15A H-frame open baffles. The top portion ( Tang Bands ) and super tweeter are powered by 2a3 Bottlehead Paramour mono-blocks ( 3.5 wpc ) SET via a Bottlehead Foreplay III preamp while the 15 inch bass Alphas are driven by solid state Dayton mono-blocks ( 150 wpc with built in XO controls ). For bass only, SS rules.

    My secondary bi-amped full range system uses a Dared 2a3c integrated SET to drive Tekton/Fostex 4.5" single driver box speakers and a JVC digital AVR to power two DIY open baffle 15" Alphas bass augmentors.

    My bedroom 5.1 full range single driver system conists of four DIY Fostex based Frugal Horn Mk3 ( back loaded horns ) with a DIY Fostex center bass reflex design and Velodyne sub powered by a Pansonic XR55 digital AVR.

    My garage full range system ( no where to put it in the house ) uses a Miniwatt SET ( 2.5 wpc ) to drive DIY open baffle 8" Betsy's and a Fostex made super tweeter while a Denon AVR drives the open baffle bass Alphas.


    The efficiency rating of all main full range drivers is around 94dbs which allows the flea power SET's to drive them with ease. There are no power/sound robbing passive crossovers in these systems and all mains run wide open.

  22. #22
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    P.G, wow, that's quite a collection of audio you got going there. Based on what I have seen SET owners and reviewers report it seems like SET amp owners have slim pickins on what type of speaker can be used with SET amps. Have you ever heard a SET and speaker combination that did sounded good/great but was not a horn speaker?

  23. #23
    Ajani
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    Quote Originally Posted by RGA View Post
    if the best amps are 10 watts and under sets (and let's assume for the discussion this is true)
    Why should we assume that is true? I accept the logic that if the 1st watt sounds bad then who cares what watt number 500 sounds like, but that doesn't mean that by default the lowest powered amps (generally SETs) must sound the best. Take an interesting review by Constantine Soo of the Audio Note AN-E/D back in 2001:

    AUDIO NOTE AN-E/D LOUDSPEAKERS Review - Equipment Reviews - Dagogo

    He compares the sound of the AN-E with both Audio Note's Quest Western Electric 300B Monoblocks (9 Watt SET) & Monarchy Audio SM-70 monoblocks (70 Watt Class A SS). If not for the fact that the Monarchy eventually blew the AN-E tweeter, frankly it seems as if he might well have preferred the sound of them to the Quest. He certainly spent a large part of that review raving about the sound of the SM70 with the AN-E.

  24. #24
    Ajani
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    Quote Originally Posted by LeRoy View Post
    P.G, wow, that's quite a collection of audio you got going there. Based on what I have seen SET owners and reviewers report it seems like SET amp owners have slim pickins on what type of speaker can be used with SET amps. Have you ever heard a SET and speaker combination that did sounded good/great but was not a horn speaker?
    Only Poultrygeist's bedroom system uses horn speakers. He has some truly interesting OB designs, that are relatively cheap and easy to build. Might be fun to try one of them with a SET amp.

  25. #25
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    SET's aren't limited to single driver full range speakers or horns, they just need efficient speakers. I have some conventional Athena F2 floorstanders that are 91db sensitivity that work well with a 3.5 watt SET and can play louder than anyone would care to hear. I also have a pair of Axioms that my SET's can drive with ease. Most folks don't realize how powerful that first watt really is. There are 10 times the dynamic range in the first watt than there is in the second watt. While I don't drive my amps to clipping levels, SET's unlike SS can still sound great when clipping. SET's usually run in class A and many Klipsch owners prefer SET's to other types.

    Personally I crave the micro detail I get with a SET paired with a crossover-less HE full range driver. A conventional crossover will turn a significant portion of that first watt into heat before it ever reaches the driver so it's robbing you of both detail and power. I've a few digital and tripath amps which I like but they come up short compared to SET's. They're accurate but lack feeling and can't float notes in mid-air like a SET. I want to hear and feel "the wood" of an instrument and the SET gives me this experience.

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