How does PS Audio's amps fit into the mix? |
Muralman1, being one of those 'tube guys' I have to agree in part with you- this is something (at least for now) that I for one will not admit. IME, class D has a long way to go to beat what I see as the advantages to the amps that we make though I do not hold that out for my competition :) as our amplifiers are apparently unique even in the world of tubes.
I understand the cost, heat and size issues. However for the time being if the system is chosen based on those constraints rather than sound, then luck and luck only determines the sound of the system- no doubt why so many want to know which class D sounds the best!
If instead, the sound of the system is chosen entirely on the basis of sound quality, you get a different result altogether. Our amps were designed for performance/reliability as number one, all other aspects being secondary- we took a stand for quality in so many words. Class D was specifically intended to deal with heat/efficiency issues inside a cost model- consequently trying to overcome the issues that result flies in the face of its intention. Not to say this is wrong or bad- in fact, making the best of a situation has characterized a good bit of human behavior and consequent innovation. |
Muralman...Excelent point.
Vic |
Atmasphere...When transponders (radar response avionics for planes) were first introduced they were all transistorized except for the output device which was a traveling wave tube. The high RF frequency used by the transponder was cited as the reason for the TWT. The TWT was a frequent failure item. Thank God it has now been universally replaced by transistors.
The switching frequency of digital audio amps is well below 2 MHz, and solid state power devices have no problem at such frequency. My CI D200s (UcD) switch at around 400 KHz and my CarverPro ZR1600s (TriPath) are up to about 1.5 MHz.
I wish I could afford one of your OTL amps, which I believe exploit the benefits of tubes without their drawbacks (except cost).
. |
Muralman1...You said "Never will class D emulate the fantasyland of tube amps" but I suggest that your descriptions of your H2O amp come darned close :-) |
Atmasphere, Although the tube guys will never admit it, class D ICE has already eclipsed their performance in real world terms. Never will class D emulate the fantasyland of tube amps.
A nice The nice thing about ICE you can set it's tempo with tubes. My driving tubes are in my DAC. You'd be surprised how close class D can get to the romance of tubes by running tube signals through them. |
Eldartford, I agree, unless you consider that commutation issues often limit semiconductor switching. A tube can switch at very high frequencies. Of course the idea is pie in the sky, but the point is that the technology is still unfolding and we really don't know yet where it will go.
Although the ICE module is one of the better sounding modules right now, the technology is changing so quickly that if you are 6 months behind, its already old hat. |
Atmasphere...Since the output devices are simply ON/OFF switches, I see no point in using tubes here. The supposedly superior linear amplification characteristics of tubes would not be relevant. At the input, a tube could be used, but why not put it in the preamp. |
Atmasphere, which one was in your view the sonically 'best' switching amp you heard 3 years ago?
My admittedly very modest experience is that -- like tubed or classic solid state gear -- tubed amps can sound exceedingly different. |
To what benefit of the ice amps are the ones that use the Lundaul transformers in their amps? |
We did an evaluation of class D about 2 years ago. At that time the technology was still immature. My guess is that it is still; the best of the class D stuff, while not bad, does not hold up to the state of the art.
Yet.
It seems to me that tube and transistor technologies are both in a mature state, while class D has still a ways to go, and showing a lot of promise. If you know about price/performance curves, the significance of the preceding statement will not be lost on you! Something that you all want to keep in mind is that one of the bigger promises is that Class D costs about 1/10th that of conventional transistor amps, while the industry gets to charge about 1/2 as much at retail. It takes barely more than the ability to chew gum and walk at the same time to get why they are really here. We have 100 watt/ch. module here that is complete with heatsinks and connectors that fits inside a pack of cigarettes. It is average in its sound with respect to all the class D amps out there, but- it costs $25 in quantities of one... all you add is a chassis and power supply. The incentive to work with this stuff is powerful.
The same sort of thing happened with transistors back in the 50s and 60s- they take about 1/10th as much as tubes to make an amp of the same power, yet the industry gets to charge the same price. Of course the industry had to create a story about how the new technology was better than the prior art, just as was done with the CD. I invite you to consider that the story was made up for reasons other than performance, although as in many fields of human endeavor, performance can always be gained.
Class D lacks many of the artifacts of traditional transistor design, and are already good enough that any designer who ignores that fact does so at his own peril. It appears that class D has already engulfed the common consumer gear market- its ideal for iPods, boom boxes, car stereo and cheap receivers.
A simple tweek for many of the amplifiers is the power supply. Class D being what it is, the power supplies are subject to quite a bit of noise. A very simple means to deal with that very effectively is to use batteries- gel cells- charged by an overgrown wall-wart. Its amazing how easily that can be used to improve things. Like the CD, class D has a lowest common denominator quality. The modules are all fairly close in performance- the big differences are all about the power supplies and noise suppression- at least for now.
I'm really wondering where this can all go. For example, the modules right now are fairly complete units. But what would be possible if the input or even the output could be done with tubes? To understand where I am going with this, imagine an amplifier with a single conventional 300b that could make 50 watts and didn't make any heat. Tubes do not have speed/slewing problems- they can switch at very high speeds. Its the impedance matching issues that slow them down... I predict that in 10 years conventional transistor amps will be all but gone. |
Vicdamone...The power which an amp can draw is limited by its power transformer. No matter what the audio circuits "want" only so many amps can squeeze through the transformer. Maybe the other changes had an effect which you describe. |
Power from the wall theory?
My experience with upgrading my VAC was a night and day difference with my first class D a PS Audio HCA-2's sonic abilities. I can't say if it was the increase in amperage, the dedicated circuit, the larger gauge conductor, or the metal clad shielding, since all these changes were completed at the same time. But the difference was dramatic.
In the case of the HCA-2 it can be powered by 110 or 220VAC. While I'm not an electrical engineer, common sense tells me that if a devise can handle a 20 amp 220 circuit then giving it 20 amps @ 110 should make a slight difference especially when the receptacle is a long distance from the breaker. But then again what do I know.
Vic |
Right on Dazzdax!
I added a pic of the H2O power supply to my system layout. Check it out. It illustrates not being merely a module in a box great class D amps are much more. |
I have had a Mark Levinson 333 once that I replaced with an Accuphase A-50V (a well known class A poweramp). The Accuphase was better and more musical than the ML. In 2005 I decided to buy these Acoustic Reality amps with the ICEpower ASP1000 modules (factory direct, so no audition prior to purchase). After extended break in I preferred the sound of the AR amps and sold the Accuphase! A Swedish fellow audiophile bought the Accuphase and is very happy with it. I'm still using the ICEpower amps (now in an upgraded version) and am awaiting a pair of Soundlab A-1 to arrive.
You can regard this ICEpower amp as sh*t. If this is really sh*t then my hearing is shitty too and I don't deserve those A-1's. I would say you should trust Martin Colloms' golden ears, because those are the most audiophile ears on this planet!
Chris |
I agree with Getheleadout, and will add one more thing.
All switching amp SYSTEMS are not created equal. |
What seems to be constantly overlooked here is the Idea that most digital switching amps sound the same and have the same drive capabilities. This is simply not true.
This is as true as saying all SS amps sound and drive the same all tube amps sound and drive the same.
I think it's just a convenient way for people who obviously don't like switching amps to lob them into one category.
ALL SWITHCHING AMPS ARE NOT CREATED EQUAL. |
Warrensomebody...That "power from the wall" theory does not make sense to me. Say what you like about the way they sound, but digital amps make very low demand on input power. They are typically 85 percent efficient in converting wall power to audio power, whereas the typical SS amp runs 30 to 40 percent. Don't ask about tube amps! |
Warren, I'm guessing your friend with the electronics background is more than likely correct. I highly recommend you invest a few dollars in a dedicated VAC shielded 20 amp circuit to your audio system. The sonic improvements can be very noticeable regardless of your amplifier choice.
Any future auditioning of class D products should be done after upgrading your VAC, a long run in of the components, using a shielded power cable, and speaker cable suggestions by either the manufacture or by users who have similar amplifier / speaker configurations. These are some simple generalities that can provide a starting point for integrating class D into a system.
Regardless of your efforts in integrating a class D amplifier into your system you may simply not care for the obvious difference in their general presentation. From your description I'll go out on a limb and say, I don't believe you heard the bel Canto's full potential. If your looking for a "tube like" presentation, buy a tube amplifier there are some terrific and affordable choices out there.
Take Care
Vic |
I wanted to believe... but all I can say is my take on class D amps is that their performance must be highly dependent on the system they're plugged into. I had read all the glowing reviews of the Bel Canto Ref 1000s, and sprung for a pair and was sorely disappointed. I tried them on my nearfield towers and they sounded weak and thin -- all treble and no midrange at all. Then I tried them on the subs, and it was the same story -- extremely weak bass response. I A-B'd them with several other amps I had on hand, and they were dramatically worse than all of them (a Classe 10, Proceed HPA-2, and a 300B SET).
A friend with an electronics background offered a theory on why they didn't work for me -- I'm not sure whether it's true or not, but I'll offer it here to see if you guys have any thoughts on it... He said that the performance of switching amps like the Ref 1000s are highly dependent on their ability to draw current from the wall. If the power lines can't deliver the current needed when the amps demand it, they completely fail to deliver the signal. I don't know if that was the case here at my place, but they definitely didn't work for me.
The Bel Cantos taught me a valuable lesson -- you can't just go by reviews. For the forseeable future, I'm sticking with amps with big capacitors. |
"pls look at the Nuforce site under the award and review menu....the quantity of enthusiastic reviews by TAS, 6moon, Stereotimes etc is embarassing!!!!"
Drooling is embarassing indeed. If you look again into TAS review - it is compilation of three different reviewers. two gave excellent review and one terrible.
Why? Is this one professional reviewer is deaf? No, read again TAS it gave NuForce Editor Choice Award but with the caveat - ineractions with cables (and obvuously speakers).
I know this amp cannot drive electrastatic Martin-Logan speakers (not poorly drive but not at all - coming the the region of difficult impedance and shut itself (v1 for the record).
Without going into engineering as to why let me simply state that despite multiple positive resonse and even drooling ==> BUYER-BEWARE !!!! Good amplifier but not for every speaker! |
Absolutely agree!!!!
Nuforce Ref 8.5 was quite an old piece of hardware, even the difference between Ref 9 and Ref 9V2 is huge.
So the comparison between D-class models should be done with the current amps version that is Ref9V2.
I recently added the Nuforce Pre P9 to the chain...
Never ever heard something like that!!!!!
but you do not have to believe me!
Listen to a Nuforce chain to a dealer near you!!!!
pls look at the Nuforce site under the award and review menu....the quantity of enthusiastic reviews by TAS, 6moon, Stereotimes etc is embarassing!!!!
but listen before judging! |
PHD,I must add that you ae definitely a gentleman!
BEST. |
Sajran has quality sources, keen knowledge of what actually works in given systems, and an open mind. Read his review of Henry's H20 amps done a couple years ago.
I have monos of his that have a B&O improved ICE module, and much better bypass caps. The sound just got better.
Class D amps, the great ones, must be fed impeccable signal. Any source, wire, and pre-amp negatives will be exposed, much to the listener's discomfort. |
Sirspeedy, it is excellent that we have all agreed that a reviewers conclusions are a matter of opinion but can point one in a certain direction resulting in either a positive or negative experience. Although most of us read reviews from time to time some people pay little attention to them. An example would be of a local hifi dealer that has been in business since the forties. I have gone in there enthusiasticly with a glowing review in hand over a certain product. His response was I wouldn't give you two cents for any review and recommended trying the product first hand to see for myself. |
"At present we have to take the prudent view that good sound might be possible from switching amps, but we haven't heard it yet."
Yes, that is prudent a view indeed. It looks to me like the author seems to have sampled a narrow mixture of usual suspects built to a narrow pricepoint, and not necessarily the latest versions of at least one of them. Obvious holes in the samples are the Spectron Musician 3 Signiture sitting towards the top of the price sampling range, definitely worth a listen. . . or 2, or 3 times )(see Neil Gader's review update in TAS 176); JRDG has a lineup of class D models ranging from $4K to $30K with a proportionally wide spectrum of musical performance characteristics among which the 312 remains my current favorite amp of any class; Genesis has models ranging from under $5K to over $25K; Kharma has 2 models if I recall, one set of monoblocks for under $10K and the other reference level set costing perhaps $40K or so; Mark Levinson is preparing a set of reference level monoblocks in the $40K range. . . . I bet I haven't even scratched the proverbial surface. I venture to suggest that the author may want to consider broadening his reviewing sample starting today. . . he may find some results of current implementations delightfully surprising. . . As for tomorrow, it is in the future and as such is not worth talking about.
Guido D. C. |
PHD,I understand your point,and intent.I have no problems with this,and wish you the best.Please understand I am not arguing about specific match-ups,in a controlled environment,which a reviewer(and some lucky hobbyists,with extra dough)is privvy to.
I must add though,I have made the aquaintance of quite a few reviewers over the years.A few are still friends of mine.There is definitely a contingent of "some",sadly,who are hobbyists,and getting a break on equipment is what got them into this,in the first place.I do not meander too closely to these "guys".
Yes,some get paid(according to my sources, "on time" payment can be like pulling teeth,at times),but I don't believe it makes for the lions share of their income.Kudos to them,and I could not go through the constant swapping in/out of stuff.They are certainly patient,and dogged in persistence.
As to the better ability to make a judgement,as compared to the average audiophile....based on your "very good" arguement,I'd agree with you(in those specific circumstances),but I have heard more than a couple of set-ups(at reviewers' homes)that were not in the same performance class,as some of my "average" audio pals.Actually,they are quite experienced.
I mean NO disrespect!My particular tastes are unique to me(btw,I have been at this almost four decades)and I have learned that I want a particular "voicing" of the reproduction of music,in my given room,to sound a certain way.My way,for me.
Many of my audio group(some retired scribes)are adamant about hearing things,as they want it to "impress" their own tastes.I cannot tell you how often there is a disagreement,amongst them,with the "latest" rave,or even good review.It often totally contradicts a given reviewer.
Of course,I would not want to be without the benefits of reading good "responsible" reviews,and DO believe there are quite a few fine reviewers(my favorite being Srajan E. of "Six Moons"... He seemingly a very down to earth and responsible writer and I hope I spelled his name correctly).
Experience tells me to take a good review with a grain of salt,and auditioning something in person IS the only way to go.
Even you have seen,too many times,specific high profile reviewers(I won't mention who)go crazy over a given component(and yes,plenty of folks jump on these products,just from reading the review)and make mention of significant shortcomings suddenly noticed some months later.For whatever reasons.Money well spent,by the highly influenced purchasers?I was at an importer's home,after J.V. wrote the, well deserved, good review,of the Kharma 3.2's.He sold 19 pairs,that week,over the "phone".
So,with due respect(and believe me,I consider you someone to admire)I can't see anyone with a good set of ears,not using their own intuitive instincts, to make a buying decision,first and foremost,and being confident in their own decisions.
The reviewer's job,to me,is to point us in a direction he/she feels is the right path,but sometimes it won't jive with where we want to go.
warmest regards. |
class d works great for bass amplifiers Ive tried many some costly as all heck.Not my cup of tea. Maybe in a few years time class d will sound better for audiophile use.Till then I use ice moduals as bass only amps. |
Stehno, that is what I hoped to convey in my post which is why you and I are actually in full agreement. |
Phd said,
"Note, they also bring to the table their own personal preferences & expectations on what sounds good but none the less reviewing products is what their paid to do & thats what they do all day. Also they have at their disposal several other pieces to try with the product that is under review. Not to mention a large stash of power cords and interconnects to experiment with that sometimes cost more than the piece itself. I would like to think their opinions are unbiased & not influenced by the magazine they are writing for nor the company that is submitting the product for review."
There's a lot of assumptions there.
-IMO |
Sirspeedy, I would like to offer some thoughts on why a HiFi reviewer may have the ability to be more accurate on his conclusions on any given product over that of the average audiophile.
It isn't that the reviewer's hearing is more acute than the average person. Note, they also bring to the table their own personal preferences & expectations on what sounds good but none the less reviewing products is what their paid to do & thats what they do all day. Also they have at their disposal several other pieces to try with the product that is under review. Not to mention a large stash of power cords and interconnects to experiment with that sometimes cost more than the piece itself. I would like to think their opinions are unbiased & not influenced by the magazine they are writing for nor the company that is submitting the product for review. Over a period of time of reviewing different products & if most readers agree with their conclusions they will build a good reputation for accuracy.
Class D amps have alot of potential and although Martin Colloms has basically dismissed them as less than audiophile grade, it really comes down to a matter of opinion as there are other reputable reviewers & users that have reached different conclusions. In fact some models have attained a Stereophile Class A recommendation. For myself I will always keep an open mind & continue to read other peoples opinions & recommendations with great interest although I have expressed my preference for analog amps, that could change in the near future.
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Muralman1
Check out the Cardas site. Just about all of binding posts will fit the cut-outs on the H20. Avoid nickel in favor of pure copper or better such as the CCGR (short) binding posts. For RCAs, Cardas GRFA RCA chassis mount jacks are better than stock and not too expensive. A very hot soldering iron is required to replace the binding posts and the leads on the modules need to be unplugged to avoid heat damage.
For isolation, consider a pneumatic platform or FIM style bearing platform with ceramic bearings.
http://www.kosmic.us/resonance-fim.html
Bob |
I haven't read the review or the system he used to evaluate the amps. But I would guess a reviewer would use as revealing as possible setup. In my limited experience, I'm not so sure that would be the best for evaluating Class D amps. If anything, they are highly revealing themselves.
I have the CI D200's driving Vandersteen 3Sigs. The Vandy's are on the dark/warm side. The CI very much brings out the best of these speakers. It's as if a thick blanket was removed when I went from my McCormack RevA Gold to these. At first, it was distracting to hear that much more resolution and imaging. The Vandy's still retained the subtle warmth, but added the accuracy.
Point being what's been said many times.. system matching. I use a tube preamp (Modwright SWLP) like many others. I wouldn't pair them with SS or mini monitors myself. I thoroughly enjoy these amps. |
Phaelon,I should have said.."any music lover with a goodly amount of experience in this hobby".I have been at it 39 yrs,and most of my friends have been at it at least as long.
None of us subscribe to any particular system/product topology.If it sounds goo,it is good.
BTW,living in the tri state N.Y. area I have been fortunate to be able to actually hear quite a few personal set-ups,owned by reviewers I am sure you have read.To my taste(only an opinion)some sounded quite good,and some were absolutely dreadful sounding.
Btw,I DO understand your valid point,and am in no way trying to disrespect your posting.
Best regards.
|
Elberoth - You are exactly right. The best sounding class D amplifiers - Spectron Musician III Signature and Kharma using linear traditional non-switching power supplies, and I been told by Spectron people - only due to the sound.
RF contamination indeed is a major source for sound degradation in class D - again Spectron people told me that when they re-designed RF filtering circuitry for Signature the sonic results were very impressive.
All The Best,
Rafael |
Points well taken, Bob. As an example that supports your observations, I just installed Sonicap Platinum bypass caps, and like what they have done. My speaker cables are short. I have found SC and IC insulation pollutes the signal significantly. I have yet to do binding posts or isolation. Any suggestions? |
Elberoth2
IMHO, the reasons for the mixed opinions on Icepower amps are the extent of RF present in a system, electrical isolation of the amp from the rest of the system, vibration isolation and impedance matching with the preamp.
Even the H20 with its linear power supply responds well to RF reduction measures. RF picked up by speaker cables can propogate backwards though the system. In the case of switching power supplies, there is potential to add more noise. I find that the Powerwraps are very effective at taming RF with the largest benefit on the player and preamp.
Power units that isolate the amp from other components are helpful.
For vibration control, isolate a module amp as you would a high quality front end component.
In the Rowland model reviewed by the TAS, a transformer is used to make preamp impedance matching less of an issue. The comments by TAS remind me of those made in ancient reviews of step up transformers for moving coil cartridges.
Once manufacturers consistently address this issues inside the amp, I believe that there will be little demand for traditional solid state designs.
At Dave Magnan's site he has many specific recommendations to improve the sound of Nuforce amps.
One advantage of the H20 is the roomy chassis. This means that there is room to add better bypass caps, replace the mediocre nickel plated binding posts, input connectors and improve the transformer damping. Not easy to do in small chassis amps or when the power supply is part of the module.
Bob |
I've reread Colloms's review and found another interesting point. Martin speculates (since he does not have enough exhamples of different applications of Class-D technology to prove his point), that the above avarage CI Audio resoult may be due to the liniar PS used in this amp. He observed, that switching on the amps with switch mode PS actually degraded the sound of the other system components connected to the same grid ! It may be (or may not) the reason why H2O amps sound superior to other ICEpower based designs that uses SMPS. |
R times 8man
Thanks my man!! Ain't life wonderful? Pedal to the metal here...... |
Very interesting thread. My take is that unbiased, objective evaluations of which class of amplification sounds better is impossible. Hearing, like all of our senses, allows only subjective evaluations to be made. It can not be otherwise! No two pairs of ears are created equal.
While poor design, component failure or bad system synergy can make any type of amplification unsatisfying, the preference for amplification type with relatively equal quality components is totally personal and not open for argument. To do otherwise indicates a complete lack of understanding of this subject or implies the existance of a hidden agenda. |
Crank them Skinnies Muralman1, the best Aps I ever heard, never forgot the hypnotic trance. |
This is a lot different than responses to similar questions as little as a year ago.
I love it when we get the usual tried it all and found only solid state is three dimensional.
What was your attending equipment? The rules have changed. Wires, preamps, and front ends have to be simple and wonderful. Over-sampling CDPs sound their selves flat and cranky. You just don't know that when matching them to solid state.
I am listening to the Beatle compilation, "Love, " and am freaking out!!!!!!!! |
Good posts !
Thought I'd add my near-to-be-ending experiences with excessive heat, break downs, wear and tear, cost for KT-88 tubes, big caps, lugging 100lb+ bohemeths in and out for shipping or a trip to the tech bench.
After thinking what I've been through and $$ spent, I'm ready to take the plunge on a pair of NuForce demos and be done ?
When my transport decides to take a dive, I'll find a quality way to harness my PC for a music server.
Tired of the headaches, I'm looking for reliability and cool-running simplicity. |
Well said, Denf. BTW, how do you like your UX3-SE? |
Hi Denf,
Is there any chance you were mismatching your tube amps and speakers. No disrespect, but I have a friend who continues to match low watt SETs with inefficient speakers. |
OK, I'll enter the fray here and strongly agree with Zilla.
The NuForce 9.0SEv2's are absolutely incredible amps. I was a heard-core tube-o-phile, and have had more amps, over 30+ years of chasing the audio fantastic than I care to admit, but I can tell you straight out - these are a revelation in high end amplification.
Anyone who isn't willing to at least audition these is really missing out on a huge slice of audio nirvana at a real world price. |
As I understand it the real weakness with digital type amps is that they lack 3D image depth.
Of course many people do not seem to mind this but once you have a system which has excellent front to back depth there is no going back.
I have friends that have owned,used and built all sorts of digital amps and they say they have all suffered in this area compared to most tube amps and some of the better SS amps.
The latest Nuforce [V2?] amps do seem a lot better in this regard however. |
"Also,with all due respect,why would a Hi Fi reviewer have any better ability to tell whether a product(of any type)is good,as compared to any other "music lover"?"
IMO, a reviewer's value stems from his access and exposure to a variety of associated and competing products. That's why I'm always amazed when I read a review, and the reviewer admits he hasn't fully exploited this advantage. |
This conversation will be moot,in the not to distant future.
Also,with all due respect,why would a Hi Fi reviewer have any better ability to tell whether a product(of any type)is good,as compared to any other "music lover"?
In the sports world,or as a musician,one spends a great deal of time making themselves better than the average person,at their craft.I'd love to know how I can "pump up" my hearing,and improve it more-so than they already are.
Just a thought. |
