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In Reply to: RE: At best Cheever defines the euphonic, not the accurate posted by morricab on March 31, 2014 at 15:34:24
You're talking to some people who don't listen to gear (at least no quality gear) so you're wasting your time - they won't audition Kronzilla or the numerous better examples of SE amplifiers. Heck I'd be happy if they just brought a modest Sugden A21a home to try for a weekend.I don't really blame them - I was a measurements guru - I was planning to purchase said Bryston and PMC (the ones in the recording studios), and B&W's (the ones in the recording studios). I was a pretty big Bryston/B&W booster boy when I first began. And to be fair it was a step up over the $199 receiver and Cerwin Vega stuff at the box chains.
And I would rant against tube distortion and that heck even my flagship Pioneer Elite receiver had .000025% THD big massive caps and all discrete amplifiers and a copper chassis (funny it didn't cost $55,000 like the Momentum ;-) 125 watts per channel RMS full bandwidth. WOW - Nothing could be better right?
Heck I would say things like "well B&W sells better than everyone else so it must be better or Bryston sells more than ... tube maker XYZ... so it must be better." The ole McDonalds attack.
Bryston got me into high end audio - I was considering selling my Wharfedale Vanguard loudspeakers (three way horn floorstander - an improvement on the now classic E-70) Ring Horn tweeter operating mostly at 10ohms and 95dB and could take 175 watts (steady). They were and are LOUDspeakers.
I brought home the Bryston 3B and I was stunned. How could it sound so much better than the receiver? The numbers actually favoured the Pioneer. The problem was that while it had that "grippy-tight-fake" presentation it did have an astonishingly low noise floor.
I'd still be on that path if it were not for a pseudo blind listening session of a 300B SET that is in a box (Meishu).
At that time (and still) that amp comes in a massive box. The dealer had it sitting on the floor. I assumed it was solid state amplifier. And that is important. If I had seen "tubes" I may have had a bias (I was biased against things that measured badly back then - they must be bad if they measure bad right).
So what a surprise when DIRECTLY A/B'd against a Bryston preamp/power amp of circa 160 watts of low distortion low noise floor on easy to drive speakers that the big Krell sized looking thing on the floor had superior sparkle on the treble - vastly deeper richer textures on the bass and the "dots were connected" rather than raspy and ssssshy sounding and your earlier note about the skeletal outline. Decay was much better but interestingly so was the attack.
When I asked the dealer about the mega watt amp (must be 600 watts right? - something like that) and when he grinned and said 8 watts I kind of went pale. That was kind of the epiphany moment that I wasted a decade salivating over the better specs and the better measured response.
Coming from where some of these other posters are coming from I kind of get the skepticism. I was no different sitting back in the chair laughing at the deluded tube guys obviously being duped by the higher distortion (2nd Harmonic) or whatever else they can find that SETs and tubes do badly at.
And if it wasn't for the "blind audition" (not knowing it was a SET and thinking it was a big Krell) I would be on their side telling you you "just like distortion" blah blah blah.
And to note it wasn't the first tube amp - I heard both Copland, Sonic Frontiers, Anthem tube amps, and Conrad Johnson years before and none
exactly made me think - Wow I gotta get tubes. They sounded tubby in the bass, rolled off, etc etc. Not exactly "beacons of accuracy."I always point to Kevin's review of a modest AN system - 20 years with Bryston and PMC (the stuff in many recording studios world wide). The review is 10 years old - I spoke with him on a British forum - nope not back to SS. Still got tubes.
Hi analogy is perfect.
Edits: 04/02/14Follow Ups:
NT
I love the music of ... ... Gustav Mahler
NT
Well my first "high end" amp was an Onkyo Integra A-9711...which was also a step up from my Sony and Pioneer El cheapo receivers that I started with. Still it left me unsatisfied so I started to look into Class A amplifiers, I dreamt of a Threshold but couldn't believe the prices.
Went up to a pretty high level of SS amp before finally switching over to tubes and hybrids. KR and NAT are my personal highwater marks in my system. Surprisingly, I didn't like the Einstein hybrid so much I had for about 7 months. I loved their OTLs so I was expecting a bit less of the same...it was not to be...I had been spoiled by KR. The huge NAT I have now is quite close to the KR without perhaps some last bit of "magic" that KR gives to the music.
That Line Magnetic you are using seems quite nice...are you satisfied?
I heard last weekend an all AN system of a higher level: Jinro amp, M6 phono preamp, DAC 3.1X and CDT 3.1 and the ANK (upper middle level model don't know the exact model). So, quite expensive (around 100K I would guess or more). How did it sound? Tonally quite natural and smooth, decent resolution but not world class and dynamics seemed...well a bit subdued. My NAT/Ref3a gets the dynamics better IMO. Instruments seemed pretty realistic but not jump out and grab you realistic...I can get that when I play at more realistic levels. Overall, my 30K (retail) system I thought outperformed the AN system. It seemed too "rounded", which was a complaint I heard also from a friend of mine when he heard another friends all AN system (but a lower level one with Conqueror amp, M3 phono and lower end AN K speakers). Another friend of mine tried to love an M5 phono but couldn't again too rounded sounding. Maybe AN has gone too far with all the transformer coupling between all stages?? Too much of a good thing perhaps (my NAT is all direct coupled.)
That said, I would take an AN system any day of the week over just about any SS and B&W type system.
BTW, have you heard anything from WAVAC? I heard their HE805 model (about 50K new) a few years ago and I am haunted by it. It sounded so unbelievably good that I am dying to hear one again so I can see if I was right the first time. I had already had OTLs, Cary SET monos, hybrids and the KR by that time and I was still gobsmacked! I have also heard at great length the very best from Kondo by then and to my ears the HE805 was THE best I had heard to that point...maybe ever. The KR monos and my own VA350i are good enough to be on that level...I think, but I would like to hear again to know.
I just bought the Line Magnetic 502CA DAC (it will arrive next week) so That should tell you I am on board.
What you noted with Audio Note this time was no mention of a shout. My recommendation with them is to just give them some more auditions over time. It's not a leap out and grab you sound - and to be blunt I hated them the first time I heard them. I think I know what you mean by the "rounded" commentary but personally after long periods of time with it I have found that what other systems are producing is a fine sense of grain in the upper frequencies for added sparkle.
And I will say that a stunning improvement is the new Alnico tweeter and woofer in the AN E/Spx HE Alnico model in Hong Kong (Product of the Year winner here) for around $20,000US.
Last note: The fact is that AN runs a complete system - if one part of it is not desirable the whole thing will fall short for you. The gear stands on it's own - it's not like you have to run their speakers for example. It's just not going to do it for everyone. Same for the amplifier - I love the 211 but plenty of people much prefer 300B. I heard Shindo Petrus preamp with AN 300B Kegons with the AN E/Alnico at an audiophile's home here playing big Chinese drums direct to disc master and it was jaw dropping big scale.
Unfortunately, while Reference 3a is finally here (the entire current line up in fact) the sound has been rather middling due to the fact that the store owner is running Solid State - the tripped up treble doesn't let me engage and the BE tweeters just tell me more about how bad the solid state amps sound.
What on earth possessed them not to run a quality tube amp is mind boggling - that's part of the reason you buy tube friendly speakers. Fortunately, I know how good Reference 3a CAN sound when set-up properly with appropriate equipment but Ref 3a should tell the HK guys to bring in a good tube amp or a better SS amp if they must use SS.
NAT unfortunately is here but the dealer has Avantgarde with them. The speaker is probably better than what I heard but apartment living space is just not ideal for those loudspeakers and it's not like the amps, or the ones from AMR that they carry, need super super high efficiency speakers. They also carry YG Acoustics which was unlistenable at CES to me but one of my four favorite rooms at the California Audio Show (how's that for polarizing!) So perhaps if they have that combination going it would be interesting.
True there was no shout but this was the highest level of AN (UK) that I have heard so far. I have heard the absolute to of the Kondo tree (Gaku Oh and their more recent 211 based monos) M100 preamp and M100 DAC and found them to be quite special.
While there was no shout, I still wouldn't classify the sound as realistic in some ways. In that sense it was too lacking to lay out that kind of money. What I would really like to hear are the AN (UK) Kegon parallel 300B amps and a DAC 5 signature but I am still not convinced by the AN speakers...really the bass even though in a corner was not as good as I get with my L'integrales, which have really a superb bass...much better than the MMCs I have or the Royal Virtuosos I auditioned a while back (those were pretty great though...better than my MMCs I think).
I would never run Ref 3a with pure SS, except for maybe BAT or Edge (NL series). My NAT hybrid is excellent and so was the VAC 30/30 I sold to a friend (he also has Ref 3a MMCs). Kind of regret selling the VAC but it was just SLIGHTLY lacking that SET magic. I drove the hell out my other friend's Thiel CS3.7...only my KR VA350i sounded as good on his Thiels and world's better than his Octave monos.
I think the E is one of the more transparent speakers around and the most cohesive of 2 ways I've heard - properly set-up they can create in room pressure of instruments that very few speakers possess - even very large speakers. I quite enjoy reading the polarizing commentary on the sound of the loudspeakers - I've read them for years. (Too bright, too dull), (huge bass, lightweight bass), (vague soundstage, Panoramic soundstage, fills the room like MBL soundstage), vocals are crystal clear, vocals have a hand cupped feel), (Bass is slow, fast, tight, coloured, clear, warm, lean).As an AN speaker owner (having owned or continue to own the AN J/Spe, AN K/Spe, and AX Two) I am not the most objective person on their sound.
I am leaning to the AN E/Spx HE Alnico as the next speaker if I can sell off some things. The reality is there is a space element to be considered. Bass is a funny thing - my KEF LS50 has deeper punchier bass than the AX Two - and it's a terrific standmount that is getting worldwide hype from the press and owners. And I like it - but If I had to keep only one I'd keep the AX Two. For all the hi-fi things it's not - it's a more engaging loudspeaker to listen to to me. I'd still like to hear Line Magnetic's loudspeakers based on those WE designs.
Edits: 04/05/14
VA350i How can any amp with antique tubes continual deteriroration 3% THD sound close to the original Live sound ?
Because it does. My ears tell it like it is and the best reason beyond that I can give you is that the distortion is primarily 2nd and 3rd order harmonics with no really high order harmonics. This means it is basically inaudible or do you not "believe" in the research behind psychoacoustics? Furthermore, KR is one of the few SET manufacturers that uses a properly specified output transformer that keeps bass distortion very low and thus eliminates the "tubey" coloration you are probably equating with "tube" sound.
If you ever get a chance, listen to a good OTL amp from Atma-sphere for example. You will realize that tube amps without the output transformer are lightening fast with deep tight bass and not a scotch of "tubey" coloration. It is the output transformer, not the tubes.
Finally, as far as a low frequency linear amplifier, the triode tube is still the closest to linear of ANY amplification device. Your beloved bipolar transistors are the LEAST linear...period! This is an incontrovertible fact... If you want to discuss other applications and suitability then we can but for an audio frequency amplifier triodes are NOT obsolete.
I have listened to many valve amps over many many years at audio shows World Wide, I agree,the distortion is mainly 2nd harmonic, and the transformers have to be very expensive I used to own both Quad & Radford, today I would not touch any antique tube amp with a barge pole that includes so-called modern ones. I listen mostly to mch SACD. I have much immediate experience with Live v recorded sound only Class AB does it for me.
Well, that's what I use, what's wrong with that?
You are the sole arbiter of how enjoyable your stereo is. No topology is perfect and arguably implementation matters more than technology and topology anyway.
In my dotage I'm even considering playing around with some low power amplifiers just for fun. The dynamic range of my ears ain't what she used to be so I really don't need much average power which opens up a lot of options, especially that of using really fast parts since the SOA shouldn't be of much concern.
Regards, Rick
Amplifiers are all typically measured at maximum or near maximum levels. Solid State measures best at near maximum levels and tube amps measure their worst at maximum levels. BUT, Tube amps(SET) measure their best low levels - distortion decreases the lower in level you go. SS amps typically increase distortion the lower in level you go.
And this is the point that gets missed - if you have a low powered SET (with no feedback) and High Efficiency speakers the distortion is vanishingly low. No one is liking the tube amps for second harmonic distortion because there is none. The amp only distorts when it is over driven. Solid state amps with crossover distortion (A/B types) are operating in distortion all the time because most of the time on most speakers the amplifier is drawing less than 10 watts.
If you have a class A/B amplifier where the amp operates say up to 5 watts in class A and then crosses over to class B - then every time the amp needs to draw more than 5 watts it switches. A to B - B back to A and over and over and over in one song. Fluorescent light bulb syndrome.
The fact it may measure great steady state at 150 watts is all nice and fine but what is it doing in real world - and people with decent hearing are bothered by this fluctuating (perhaps subconscious) irritation(hash) like a mosquito buzzing around your ears but you can't quite see it.
Listening to a good tube amp (and there are many bad ones) for a long period and then flipping back to a solid state A/B and I think the difference becomes much more apparent as to what the SS amp is missing.
Typifying the A to B operation as "switching" is baloney.RGA's ignorant nonsense ...
" The fact it may measure great steady state at 150 watts is all nice and fine but what is it doing in real world - and people with decent hearing are bothered by this fluctuating (perhaps subconscious) irritation(hash) like a mosquito buzzing around your ears but you can't quite see it. "To be better informed, read the article below by Nelson Pass ...
Excerpt: Nelson Pass ...
We get a lot of questions about this. A typical email reads, “I can’t sleep at night – I keep worrying about where my amplifier stops being Class A. As I listen to my system, I think I can hear the Klunk as the special Class A part of the amplifier kicks in and out!”
For starters, there is no special Class A circuit that kicks in and out, and for that matter, there certainly is no Klunk. There is just a push-pull amplifier output stage which is operated at a constant idle current known as the bias. In this regard, our power amplifiers are like other amplifiers on the market. The vast majority of amplifiers are push-pull designs with a certain amount of bias current.
I love the music of ... ... Gustav Mahler
Edits: 04/04/14
Where did I say there was a klunk?
And Nelson makes some of the best solid state amplifiers around that are also fairly affordable but I believe the entry level integrated is still $6,000+ (the distortion is referred to as notch distortion in B/AB designs). I have been exploring the notion of buying a Pass Labs amp and bringin in one for review but I need to get some things sorted out first (like a preamp).
Most people who buy the big dedicated power amps own low efficiency speakers - and you always hear them bemoan the fact that they need more power cause their sound is unclear and often muddy.
Looking at the link you provided we may actually have an inkling for WHY that is the case. Very likely not the overall higher watts of the amps but the higher availability of class A watts. As it goes from 16 watts to 118 in their first listed series of amps.
And many audiophiles much prefer his First Watt amps - which is a different animal.
However, when the amp is leaving Class A it is possible that it will be heard depending on when it moves to AB (actually B because at that point it will cutoff at zero crossing). If the speaker is pretty insensitive and the bias only a few watts then probably quite a bit of listening is done in B or at least at low enough volume levels that the added distortion might be audible.
If you read Boyk and Sussman's simulation paper you will see that MOSFET Class A PP output stages are actually theoretically perfect...real world says otherwise but they get close. When they go into Class B (when the bias runs out so to speak) all hell breaks loose and they distort pretty badly. Funny enough bipolar transistors are less Schizophrenic... they just have quite a bit of distortion all the time unless you use a lot of negative feedback.
A Class A MOSFET single eneded stage is quite interesting because it has only very simple low order harmonics and CANNOT leave Class A (it is single ended afterall).
So, while Nelson is right that it is not so abrupt as to have a "klunk" it might be audible if the amount of Class A is low and the sensitivity of the speaker is also low.
Obviously, an amp that runs 20 watts in Class A will be in Class A most of the time with most speakers.
That is, to eliminate so-called notch distortion. With adequate transistors this occurs only at very low output levels and transitioning to class B adds no distortion at higher output levels.With good design the class A is only "insurance" against minute residual notch distortion. Enough bias, however, should ensure no abrupt, significant increase in distortion.
At the levels I listen, my Pass X150.5 is probably operating mostly in class A. In any case I don't hear any "klunk" or "florescent bulb" effect as RGA would have it.
BTW, according to Pass the X series amps operate single-end class A at very low levels, i.e. below one watt.
I love the music of ... ... Gustav Mahler
Edits: 04/04/14
What you say about Class B is not true there is distortion beyond just the crossover notch distortion. Boyk and Sussman demonstrate that clearly with the math. With or without feedback it is FAR FAR worse than Class A...otherwise no one would have ever bothered with a Class A amp in the first place!
Read Cheever about the level dependence of harmonic generation and also the sliding scale of perception...it's a complicated story but worth telling. Your Pass is probably 10-15 watts Class A so for most listening it will stay Class A. Whether you hear the switch to Class B will depend on speaker sensitivity and impedance, meaning it depends on how loud and what power draw is occurring as to the audibility. This means the amp speaker interaction but not for the reasons people usually think.
"...otherwise no one would have ever bothered with a Class A amp in the first place!"
I'm only semi-ancient but when young had lot's of experience with gear that was old even then. So... from that perspective, i.e. historical, you have it wrong. Single ended amplifiers have the advantage of the lowest possible parts count (and cost). Tubes used to cost a bundle and had wide production spreads so needing twice as many and matching just didn't cut it.
Historical Rick
I was referring specifically to PUsh/pull amps since Single ended can only be Class A anyway. When the first decided to make PP amps they probably took one listen to their latest Class B creation (early transistor era just for HR) and said OH F#$K what a piece of S$*T!! :-)
Morricab: Triodes v Bipolar Anything to say re the Humble contribution ?
Edits: 04/05/14 04/05/14 04/05/14
What are you looking for exactly? There is not much to say except that triodes (not tubes in general) are much more intrinsically linear that a bipolar transistor?? It is a simple fact. Transistors were never really designed for audio amplification (computer sure, audio not really). They were designed as digital switches not linear amplification devices. THey have way too much gain for audio purposes NECESSITATING the use of lots of negative feedback to work at all. This is where MOSFETS have an advantage that they can be run without feedback in Class A and work very well indeed.
The only significant drawback to triodes is that they need either a VERY good output transformer to match well with speakers OR you need a bunch in parallel to get the output impedance low enough. Otherwise, they are in just about every way superior to the BJT.
Morricab The earliest transistors from the late fifties were in three groups,
Red spot for AUDIO,Green spot etc for RF, and Yellow spot also for RF for the intermediate filter stage in radios all germanium then, and today Companies like Profusion have a catalogue of Bipolar and Mosfets specially designed for Audio.People should check their references, which includes how transistors actually work , and that constantly repeating a statement without defining the limits simply confuses the situation. I think I have more than adequately answered the question of triodes and their distortion characteristics and the conditions under which it is evident, and why it is evident. I have also emphasized that transistors are as different to valves as Blancmonge is to cheesecake, but that transistors can be configured in so many ways that valves cannot and thus in the area of distortion or linearity makes arguments moot since the Transistor circuit beats the valve hands down and that is a fact. Any transistor can be used as an amplifying device, the term "Switch" simply means that the transistor has been designed for a very low input capacitance and thus it is capable of working well at much higher frequencies without transit delays, but will work perfectly well at audio frequencies... this comes from my friend Humble
Edits: 04/07/14
Yes but unfortunately Nelson Pass doesn't design most amplifiers on the market - nor are most of them anywhere near as good.
Somewhere in this thread I noted that I liked certain SS amplifiers more than tubes - umm Pass Labs/First Watt is one of them - Sugden is another.
I am looking to build a SS system because I think it's helpful for reviewers to have both things that people like (ie; tubes and solid state) and Nelson's stuff tops my list). There are others but they usually cost ridiculously more money.
I tried going tubes, but found most tube amps to sound slow, soft, and lacking in dynamic punch. As mentioned- I like a quick/fast sound with punchy dynamics that really kick the speakers when it hits. I don't get that from tube amps.
I have heard the same thing - there is no inherent superiority going to tube amps. The tubes themselves can also suck or just not be right for a given amp.
One of my earlier auditions was with the Jolida 302B and Antique Sound Labs AQ 1003DT - both were about $1300 back in the day - both are similar size and both use EL34 output tubes. Played them back to back. The Jolida is closer to the way you describe - the ASL was completely the opposite and solid state like in terms of grip and speed. Total shocker at how truly different the two tube amps sounded. In the same store if you lined up the Bryston, Classe, Ayre, Sim Audio, Musical Fidelity amps of similar dollars - the differences would be nowhere even remotely as big as those two tube amps sounded.
This is partly why tube amp makers make a wider array of tube amplifiers. There is a "sonic envelope" that tube amps possess. Some guys like the softer rounded smoother sound - some want more visceral impact, some want a blend of both, some want drive, others want "beauty" etc. Accuracy is in the ear of the beholder. SOmething is either accurate or it is not accurate - 2+2 has only one right answer and no stereo system at any price is the answer 4. So whatever you got ain't the "accurate" and thus "correct" answer. So once that is accepted you may as well buy what you prefer. If that is SS or tube it makes no difference. All the forum chatter is simply talking points for people (including me) to explain what it is that we/I think leads to better sound reproduction.
It's the same conversations over and over 10 years ago, now, and ten years from now. I've heard far more tube amps that I would not want to own than tube amps that I would want to own. And there are several Solid State amplifiers that I think are better than tube amps.
But here's the thing - both are coming down in price - people can buy both. It's the same with vinyl/CD - you can buy pretty decent turntables complete with arm and cartridge for under $500 so who cares about "which sounds better vinyl or CD?" Buy one of each. Same for tube SS or low efficiency and high efficiency loudspeakers.
What you need to audition then is an OTL amp. THey are lightening fast and don't sound tubey at all! If you don't mind the heat then you will stay in the kitchen...for a long time!
Most tube amps have inadequate output iron on them and it gives the tubey sound. OTLs have no output iron and so don't sound that way. It will be an ear opener I promise.
IMO the nearest approach to original live sound is obtained from Class AB amplifiers but not integrated Brystons.
Edits: 04/04/14
"How can any amp with antique tubes continual deteriroration 3% THD sound close to the original Live sound ?"
Although I use SS gear I grew up in the tube era. I suspect that the THD that you mention may be actually be used as the threshold defining the "maximum power". Tubes, especially when running single-ended, have their worst distortion at the loud-end where your ears are the least sensitive to it due to their own distortion while most transistor circuits have their worst distortion at the soft-end where your ears are running at full gain with low self-distortion. Even when you run transistors single ended they tend to have significantly more higher-order distortion than tubes do, it's just an artifact of their transfer functions.
But, on the other hand, transformers suck and it's expensive to build good ones so most solid state designs eschew them as their lower impedances make that a viable option. The result is a semi-general rule (from my experience) that SS amps have more accurate and 'tighter' bass while tubes have a more open and natural sounding treble. The engineering says that and my ears agree.
HOWEVER, either can provide excellent performance, or not. It's just that different topologies have different things that they sort-of do well just by default and their weaknesses have to be addressed by good design and added expense.
The future looks rosy, I predict that "chip-amps" and "class D" used within active speakers will drive up performance and drive down costs. Our system topology is archaic garbage and audiophiles try to work around it by careful matching and spending money. This too shall pass...
Rick
In fact it is. At a more normal 1-2 watts the distortion is very low as it increases with output power. Also, it is nearly all low order harmonics.
As for transistors single ended...that is what I run now (although it is a hybrid with tube input and driver stages) and it is slightly different sounding than a really good SET for what I think are two reasons: 1) It has no output transformer so the distortions caused by those are not present (gives a more OTL like character then) 2) As you mentioned the transfer function of a MOSFET is not the same as a tube; however, MOSFETS tend to follow a quadratic function and when run Class A and this leads to a somewhat limited issue with high order harmonics as compared to the exponentially non-linear bipolar transistors.
Read the simulations done by Boyk and Sussmann:
http://www.its.caltech.edu/~musiclab/feedback-paper-acrobat.pdf
I do find that the NAT does not quite have the holography of a top set but it is very very close and superbly transpaent and holographic. As you might expect the bass is quite tight and controlled.
There is a good reason though that KR gets the reviews it has...it really is that good. Anyone who heard otherwise either heard them with really incompatible speakers or the source was inferior (regardless of the price) because the amp gives sources nowhere to hide.
WHat I still want to try is a SET OTL. To my knowledge, only Transcendent Sound makes one. The problem is tha I think it requires feedback to lower the output impedance to be practically usable for normal speakers (headphones though it is THE way to go). Too much (well any is too much) and the sound "dries up" and sounds unnatural.
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