I agree with the part about a stereo sounding loud. It's one thing the Krell really excells in.
I did say even a Krell can't make a bad design sound good.
I also agree wholeheartedly that belief and fact are often quite far from one another. Most people believe what they want. And most audiophiles believe all sorts of pseudo science. |
Rwwear, just to set the record straight, an OTL may have a lot of tubes but that is not the same thing as being really expensive and difficult to maintain (although the Fouriers did contribute mightily to that myth).
Krell is correct in that a high damping factor is not needed, even for speakers that operate under the Voltage Paradigm. In fact, the appearance is that the idea of damping factor is mythological, regardless of paradigm. That is a discussion for a different thread. Anyway, Krell is not the only ones that have cherished linearity in an amplifier. If I had to guess :) I would guess that nearly every amplifier designer holds linearity as a primary design goal. But I don't have to guess :)
It is how the designer acheives linearity that is actually the issue. If one does it through the use of negative feedback, then some primary rules of human hearing are ignored, resulting in an amplifier that exhibits loudness. Believe it or not, a stereo should not sound loud regardless of how loud it is actually playing. In order to do that, you have to get rid of loop negative feedback. In doing so, the difference between the Voltage and Power Paradigms is defined. So it is not about tubes/transistors, although quite often that is how the debate appears, it is not about objectivist/subjectivist, although again that is how the debate often appears.
Speaker designers over the years have designed for certain characteristics that they expect from an amplifier, and thus logically and also quite contrary to the words in your owner's manual, there is no amplifier made that will properly drive all speakers made. I allow that you can disagee, but your disagreement will not change this fact, its sort of like you trying to convince me that the sky is green all the time because that is what you believe. Belief and fact are often quite far from one another. |
Tube bass can sound bloated with the wrong speakers, with the Merlins the bass sounds like live acoustic bass does live, which is not very tight, to my ears, most SS makes them sound like one note, consitpated with no bloom, lack harmonic complexity, and natural decay (pretty darn good with Pass Alephs and XA.5 though, and I suspect the Ayre and a few others). I never heard the Krells you own, though the ones I have heard never came close to making me thing I should move from tubes, so I can't really say what they would sound like with the Merlins, but if it can sound great with every speaker then it must be a great amp. If I understand Ralph correctly, such an amp cannot exist due to the different amp/speaker paradigms he describe, but maybe the Krells you own have found a way to do it. |
I like tubes also and have a tube amp in another system. Maybe you didn't read all of the above posts Pubul57. You are correct tubes can sound wonderful but cannot work well with a large array of speakers like a well designed high current amp. An output transformer with hundreds of feet of wire can cause muddy bass response, loss of transparency and a rolled off top end.
An OTL amp requires many tubes to get the output impedence closer to a speakers. Which is why they work better with high impedences. But many tubes are costly, hot and hard to maintain.
I think when you say your speakers suffer in bass when used with an amp with damping you are mistaking boominess for true bass response. The same thing happened when I used Audio Research Classic 120s with Mirage M1s. The bass was very bloated.
Krell does not claim a high damping factor and claims it is not needed. What they do is build an amp that not only is fully balanced on the input side it is fully balanced at the outputs and controls a speaker's drivers in both directions. |
Rwwear, I happy you have found an amp that is wonderful for you. I don't have a particular attitude towards Krell, I know my speakers, and I know they sound better with tubes. No matter what Krell is doing, their amps do not operate like tubes and for your speakers that is proabably a good thing. Whether linear or not, the damping from a Krell amp would choke the bass performance of the Merlins which need low damping to perform their best. No disrespect, but I'll take Bobby and Ralph's advice on the amp/speaker interface appropriate for their gear. No amp is, or more importantly, can be right for all speakers IMHO. |
Pubul57, with an attitude like yours I'm sure you wouldn't like Krell.
From Krell's manual:
Krell amplifiers are best known for their ability to drive any loudspeaker to sound
its best, without regard to impedance or efficiency. I believe that linearity, an
amplifierÂ’s ability to output an exact duplicate of the input signal, is the ultimate
measure of that amplifierÂ’s work. At Krell, I drive amplifier designs toward the common
goal of linearity, through the rigorous application of Krell design principles
that focus our efforts on four major performance factors: distortion, bandwidth,
output impedance, and current capability.
You can and should be skeptical of all things until proven.
My experiences have been very favorable so far. |
There is no need my two cent on the technical aspect here with Ralph on the thread, and due to the fact I know close to nothing about electronics. But it I had a choice of an amp that brings out the best in my chosen speakers (Merlins) or an amp that will work very well with more speakers, but not be the best with the Merlins I would choose to find an amp that is ideal for my speakers. I've not heard the Krells but I'm 99.9998% sure that they would not make me happy. I'd rather spend the time to find an amp like the Atma-sphere or Joule (and a few others) that drive me Merlins which make music in a way that I prefer to any other speakers I've heard. Amps that drive the B&Ws great are no good for my Merlins, and vice versa. |
Atmasphere >> I think we are both wasting our time here.
|
((Rwwear, FWIW they were never one of our dealers.))
It's possible we weren't but had some of your stuff around. I only worked there part time.
((Another example is the Acoustic Research AR-1, the very first acoustic suspension speaker made. Acoustic Research specified that the amplifier output impedance should be high for best results (seven ohms).))
Hard to say because Krell didn't really exist at the time. But, I bet it would. |
Rwwear, FWIW they were never one of our dealers.
The Fertin full-range driver is an extremely high quality driver, yet it is not driven well by a 'constant voltage' amplifier like the Krell. The manufacturer specifies 'current source' amplifiers for its use- these are amps with a high output impedance.
Another example is the Acoustic Research AR-1, the very first acoustic suspension speaker made. Acoustic Research specified that the amplifier output impedance should be high for best results (seven ohms).
The simple fact of the matter is not all amplifiers will drive all speakers properly, and it is not a failing in the amplifier that that is the case. It is simply that there is more than one approach to creating audio reproduction.
Note that this is not a conversation about tubes/transistors; as an example of what I mean, look at the Nelson Pass First-Watt amplifiers, which are 'current source' devices, intended to drive speakers like the Fertin mentioned above, which they do very well. So this is a matter of intent by the designer, and the designer will be the first to tell you that there is no amplifier that can drive all speakers. |
I didn't say that Oem. I think Krell will work well with any speaker if it is a quality design. And we wouldn't want anything less. But I suppose you don't actually need 1000 watts a channel for Quads. I have close to 2000 watts per channel with my 4ohm speakers and it sure is nice not to have to worry about running out of power and destroying the drivers.
I worked part time for Finale in Cartersville Ga. |
Rwwear, what dealer were you with? |
Rwwear,>> exactly my thought.Therefore by your own admission amps should be carefully selected before being placed in the system and because the Krell can drive an Apogee does not make it suitable for some other type of speaker. |
Sorry Oem, you mentioned sound quality.
The Quads are very delicate and you should not overdrive them with any amp. The newer ones aren't as bad. |
Rwwear>> with all due respect your reply did not correspond to my post. |
Oem, my Krell can't make a bad speaker sound good. If a speaker has a screechy top end don't blame the amp, blame the designer or use a poorly designed amp with rolled off treble.
Again I disagree Atmasphere I and the Fourier builders were amazed how good the 250S sounded with the big Soundlabs. By the way we were also Atmasphere dealers.
I know I won't sway you Atma you like what you want. I don't need to convince myself. I have heard most everything and I bought what I liked best. I have a pile of different amps. |
Rwwear, given the example you gave, any amp can drive any speaker. However, in the context of what has become high end audio, it will not always drive the speaker *well*. Even a set of our smallest amps can drive a set of the old Apogee Full Ranges, which are 1 ohm, but I would not say that they do it well.
The impedance curve of the Sound Lab is low at high frequencies and high at low frequencies (much more than 16 ohms). While there is little energy at high frequencies, in the case of a transistor amp, there is the possibility of over-emphasized highs, and not enough in the lows. Sound Lab is an excellent example of what I am talking about, as any amp will 'drive' them, but few play them well. Its about getting that last nuance of performance that is the difference between hifi and music. Sorry- there is not a Krell made that can really do that on a Sound Lab.
Similarly, very few transistor amps can make a Lowther or PHY sing (and all of those amps are zero loop feedback). Nor can any tube amp play set set of B&W 802s properly (you will always be 3 db down in the woofer region). It is watching this phenomena for over 30 years from the perspective as a designer ('the Journey') that brought me to the distinctions in the white paper, although everything in it has been well-known, but not always connected. |
An active speaker may work well with the proprietary internal amp but is even more dependent on the specific amp designed for it. Rwwear, I agree with you entirely. However, my point was that the speaker is designed, built, tested and specified with its built in amplifier to function as a whole. This eliminates the dependence on power amplification/load issues for THE USER by specifically designing an optimum solution for it. If you don't agree with the manufacturers optimized solution and final product, then just like with a passive speaker you are free to choose from many "active speakers" and certainly not just ATC or PMC: other examples are Meridan, KRK, Adam, Westlake, Genelec, Quested, Meyer, Tannoy, Paradigm, Linn, B&O, Mackie, Wharfdale, Klipsch, Yamaha, NHT etc. Here again I find a high current/powered amp essential. Which is also the reason I used a Krell amp when I helped design speakers for an OTL amp company. Exactly my point. Do you design the amp and spec it for an 8 ohm and a 4 ohm purely resistive load? Do you desigtn to handle the odd speaker that hits less than 2 ohms (like Infinity) and what compromises does that entail when you do that? Do you design the speaker for a high or low output impedance amp? In fact, what do you design for when building an amp? There are many choices. Do you make the amp less stable but with better specs by giving it extreme bandwidth and low output impedance?? Surely if you know exactly what load the amp is driving and over which bandwidth then you can optimize it (which is what Active speaker manufacturers try to do, often quite carefully in their anechoic test facilities with expensive test gear). Generally there is a range of what manufacturers' use to define "optimized" - from small low cost active (that use the design advantages to reduce cost or footprint) to high cost active speakers (where design is used to maximize the performance of of the combination) - you take your pick. Alternatively, in a passive setup, the USER is forced to try different components (mix and match) and "earball" things at the delaer or in the home setting and try to decide what sounds most right together. Or possibly canvas opinions of other USERS on what they agree sounds good/right. In any case, this inevitably means the USER is testing a few of what are hundreds (if not tens of thousands) of possible combinations where power amplifier interaction with a complex load will be another Isometimes significant) variable in what is heard. In the worst cases of mis-match between load and amoplifier, I would expect even minor effects like speaker cables resitive/inductive/capacitive effects (although extremely small) may start to affect the sound or stability of the combination with certain music at certain SPL's (whenever or wherever difficulty for that particular combination is encountered). The compromise for tube lovers is that no active speaker with a built in power amp will run on tubes (due to microphonics) However, the way I understand it - those who choose tubes are really looking to get a different sound from Solid State anyway (better from the tube lovers perspective), in which case, an amplifier that is dependent on the speaker load that it connects to is desirable! In summary, I tried to tackle the specific question "Can you name just one amp that is not speaker dependent" - I said there isn't one - so we agree! However, I believe that active speakers are largely independent of what they are coupled with (no "combination" effect - just the additive effect of "active speaker" response/coloration with source pre/amp coloration but NOT the additional coloration of the two combined affecting eachother in a "third' from of coloration) |
Rwwear>>> your big Krell can indeed drive any speaker,but isn't it quality of sound that we all seek.
IMHO The Big Krell is not a good match for every speaker.
I recall an instance when a Hafler 500 was driving Quad 63's.The Hafler was able to drive any known speaker at the time.It drove the Quads so well that they blew up. |
Rwwear, In addition to impedence there is the matter of Phase Angle. Some amps are simply not tolerant of huge phase angles and will heat up or otherwise show there displeasure. You made note of this issue but I think it really deserves near top-billing as a reason.
Some speakers are notorious for being bad on amps, and part of it may be not only the low dip (Apogee Scintilla?) but huge phase angles, which may be brought on by massively complex crossovers.
As for active speakers, I think one of the major drawbacks is simple economics. It is less expensive to make a speaker out of available drivers and electronic components without having to buy / vett an amp and than provide aftermarket support.
I don't think speaker designers give a HRA about amplifier designers. If they did, we would not have need of some amps now deemed 'necessary'.
I am as guilty as anyone, running 85db, 4ohm speakers, and panels at that, which are power hungry, but at least a reasonable load.
That being said, I still fondly remember my first exposure to the than new Braun Tri-amps....LV 1020? |
However you can make a speaker pretty much independent of amplification by making it "active". You mean like ATCs and PMCs? |
Atmasphere:
Do you have a notion of the PSD for a given musical genre?
Most of the power in the musical waveform is actually contained toward the lower frequencies. Since power in the signal diminishes anyway with increasing frequencies the transistor amp paradigm you presented also becomes less important.
There is no perfect solution. |
Shadorne, as much as I respect your opinion I have to disagree with you. An active speaker may work well with the proprietary internal amp but is even more dependent on the specific amp designed for it. Which is one reason such designs are unpopular.
As far as an amplifier not being speaker dependent, I have to disagree again. If an amplifier has enough current to drive the lowest impedence loads and supply increasing power into the same loads(usually lower frequencies)as well as having enough power to drive higher impedences then it will not be speaker dependent. In the same case the speaker will show it's true self whether you like what you hear or not is a matter of taste.
Complicated crossovers can also represent a difficult and power consuming load. Here again I find a high current/powered amp essential. Which is also the reason I used a Krell amp when I helped design speakers for an OTL amp company. |
I want an amp that is not speaker dependent. Impossible. However you can make a speaker pretty much independent of amplification by making it "active". In this case, the speaker includes the amp in the design process. This type design will playback whatever signal it is given just as it has been designed to do - so what you hear differently between one source/preamp and another will be entirely due to the difference in source/preamp. Studios like active speakers for this reason...plug them into a source signal and you hear the source unaffected by power amp/load interaction...a major variable is removed and a degree of precision/consitsency/translatability is added. |
I have heard the Lowthers with SETs and thought they sounded great but only with a sub. I have not listened to the Lowthers with the Krell but am sure it would drive them well but would sound different.
I also have a modified Citation II that I use in a second system. But I know it's limitations and don't play it as loud. I do like it a lot. But when it comes to truly outstanding soundstaging and stunningly undistorted but delicate power the Krell is unbeatable. I am sure some will differ in their opinion but I have heard a lot.
I do like OTL amps and have had them in my system but in general they are too too fussy, too hot, have way to many tubes to replace and too speaker dependent. |
Now if they would be driving Lowther horns would they be a good match or would you say a SET might do a better job |
I sorry Atmasphere. I just don't agree with your accessment. My Krell 700cx will drive any speaker in production. And it does it well. It will drive high impedence speakers such as Soundlab and do it very well also. People in attendence when we were SoundLab and Fourier dealers were shocked at how well my KSA 250S drove the big SoundLab 16ohm speakers. Other amps such as the Aragon 4004 did not do well. Remember even though a high current amp may have less power at high impedences, the high impedence loads are almost always at the high frequencies which take much less power and are easier to drive. |
I must say that after trying many amps of various types over the past 25 years or so, none can do (or not do) what a great OTL can do. They are not cheap, they run warm, and they do need more tubes than usual for a given power rating - but once you spend time with them there is no going back IMHO. They are slightly more speaker finicky that tube amps in general. |
|
Rwwear>> Can you name just one amp that is not speaker dependent. |
No. But some come mighty close. |
I want an amp that is not speaker dependent. Ah, the holy grail... so far, there is no such thing. |
If you say so. I want an amp that is not speaker dependent. When I don't, I listen to my modified Citation II. I'm going back to rehearsals. |
Philefreak, you should probably NOT listen to a modern OTL amp - some of your gear might end up back on audiogon. |
"First of all you english teachers out there just don't read this and we'll both be the better off for it. English grammer and spelling is something that I'm not well educated in.
Clearly, you've never encountered the word "paragraph" in your audiophole journey. More's the pity, as I might have enjoyed your story - BUT I COULDN'T READ IT...
-RW- |
Twoleftears, I too have been of the opinion that the rise of SETs had a lot to do with bad digital. In the meantime, SETs established themselves quite apart from that.
Although I have heard some very nice class D, I have yet to hear one that is on the same level as a good tube amp, keeping in mind that in that regard I tend to be rather picky about my tube amps :)
I have wanted to hear the Dalis myself with those same tube amps .. at least one person I know has them and says that with the Megalines anyway, that they are 'da bomb'. |
RWW--this is an old, tired topic that doesn't need to be rehearsed again here. And SNS has set the record straight.
My earlier post was meant as a comment on the vicissitudes of audio enthusiasms, not as a comment on the intrinsic merits (though many!) of SETs. I was arguing that I think SETs came back on the scene in a big way not because some amp designer woke up one day and said to himself "I need to use some 300Bs", but rather because, at a certain point in time, the CD market was flooded with recordings done with early DDD technology, and most of them sounded bad, with that digital glare or edginess that makes them very hard to listen to, if you've got any kind of half resolving system.
That DDD helped to bring back SETs (if such was the case) is entirely serendipitous, as SETs have many other fine qualities beyond the ability to tame digititis.
The original post does, of course, make me curious to hear the Spectrons (though who knows where, in this audio wasteland), a brand about which many eulogistic comments have been written of late. |
SETs have much more than midrange. Number one, you have to the proper speakers to match them to, its all about synergy. I've had SS, push pulls and SETs in the main room. I've also had push pulls and SETs in the bedroom system, currently have a Sonic Impact Super in the bedroom system.
So, first of all, I can hear the nice qualities of digital amplification, even when this little cheapy. I'm closely watching as they make improvements in this technology, at some point I plan to do some auditioning within my main system.
Back to SETs, they can do much more than midrange, as I mentioned, proper speakers and synergy with rest of system is required. While it is true some SETs don't cover the frequency extremes as well as push/pulls, SS and digital. Others come mighty close, or even surpass the other designs.
My current SET does bass better than my former push/pull and SS amps in the main system. Highs are only the slightest bit rolled in comparison, but even here I can compensate a good deal with a little silver in the cabling, adds a little more illumination in this frequency spectrum.
They are also not all sugary sweet, I've heard lots of different flavors in SETs.
In the end, all amp designs can have their place in a fine system, its all about finding the correct synergy. |
Yes SETs have a very pronounced midrange and that's fine if it's all you care about. And I'm sure they could be as addictive as most sugary sweets. But there is more to music to me. |
My take on the popularity of SETs was that it was driven, at least in part, by the first several years of digital recording (whether that recording ended up on LP or CD is beside the point). The first several years of DDD were atrocious: digititis, digital glare, call it what you will. The only thing to tame it was SETs. Now time has passed and things have improved some, but SETs still have that incredible midrange. And so it goes. |
You are absolutely right Philefreak, switching (or digital) amplification has come of age, and we are seeing a rapidly growing interest/acceptance in class D amplification, with brands like Rowland, Spectron, and Nuforce leading the way. . . I am not going back to low efficiency furnaces, SS or tubed alike. G. |
Great story.....udder dan da spelin an gram'r. I had some Realistic and BSR stuff back in the '70's as well. Never had any complaints about it at the time, although if I heard it compared to what I have now it would probably be lacking in a few things. Interesting comment about being around Audiogon in the late 90's after it first started. I was there too under a different username. There were a regular group of usernames who I enjoyed reading and sometimes jousting with. I dropped out of the scene once the unmoderated site became overrun with flamers and other trash. When I returned after the site was purged and the forums became moderated, I looked for a lot of those old usernames but they had disappeared. Perhaps they are around under different names like myself. Based on your experience, would are to recommend a low powered SET amp to someone who's thinking of giving it a try? I haven't heard tubes since the '60's. They're still pretty good are they? |
Great story although a little long. Yeah I first heard my first Hi Fi back in the 60's. I was about 10 and could not for the life of me figure where the band was hiding. Didnt care what the stuff was but I sure liked it. So did my parents but they didnt get as good of a system. I do remember a rca tube amp with a gerrard turntable. Then I got married. I didnt have a waf I had a wsychamfsf (Wife Says You Cant Have Any Money For A Stereo) factor. Bummer.. Over the years I was allowed a Denon Int amp a Yahama cd player and cyrus 782 speakers. I was very happy with that. 3 years ago I got divorced. Upgraditst hit. Did a lot of comparisions at dealers with what I wanted to replace with my existing equipt at the time. I noticed components got better but not by all that much especially for the money. I have almost completely upgraded everything and the combination of all the new equipt sound completely different and once again (for me at least) I sometimes wonder where all the musicians are. Guess what I'm trying to say is you get 'used' to a way that music sounds. Single upgrades cost me up to 10 times the cost of the old equipt (18-20 years ago) but only seemed to get 5-10% better sound. It all adds up but where do you stop. Damn I need to win a big lottery to keep playing this game and if I dont I'm extremely happy with what I have now. Although for a few bucks more I know I can 'change' the sound and hopefully for the better. |
PhileFreak,
Actually, your English is very good..!..LoL..I agree with you on the supremacy of tube amplification. I've been on a similar journey (i think we all have, one way or another) and would not tolerate SS anymore except for a couple of brands etc..Digital amps have failed to impress me, not even remotely close to good tube amps provided you have matching speakers with a tube set-up. At one point in time, I had SL-3's and Ascent's driven by SS electronics but still I would always go back to tubes. Anyway, if you yearn for the best of both worlds I suggest you try an Atmasphere amp with a matching loudspeaker. You will not be disappointed!..:-)
Best,
AG |
