All my amps right now are Class D. ICEpower in the living room, and NAD D 3020 in the bedroom.
I’ve had several audiophiles come to my home and not one has ever said "Oh, that sounds like Class D."
Having said this, if I could afford them AND had the room, I’d be tempted to switch for a pair of Ayre monoblocks or Conrad Johnson Premiere 12s and very little else.
I’m not religious about Class D. They sound great for me, low power, easy to hide, but if a lot of cash and the need to upgrade ever hits me, I could be persuaded.
The point: Good modern Class D amps just sound like really good amplifiers, with the usual speaker/source matching issues.
You don’t have to go that route, but it’s time we shrugged off the myths and descriptions of Class D that come right out of the 1980’s.
put your money where your mouth is and buy the EVS 1200. Then, and only then, would anything you profess, potentially have any value. Alas, you have so convinced yourself that all class D sucks, that you would have to bash it just to save face.
Get a life
To anyone else who has denied themselves the opportunity to hear which of us is telling the truth, it’s your loss.
What more could Ric possibly do than give you a money back guarantee?
I had no way of knowing whether his tweaks would be magical, until/unless I bought it. I did, and I did not return it
$2200 is an absolute bargain in todays world of uber expensive hi end audio amps
Apparently, the GaN Voyager is still going through its development issues. Why? It’s a
ground up build, whereas RIc was able to take off the shelf newest IcePower
1200AS2 modules and analyze how they could be improved, and did it. BIG DIFFERENCE
I have owned lots of TOL/SOTA tube equipment, Lector, Musical Reference RM 9, Judd Barber custom OTL amps, Rogue M150s, and lots of SS amps; Parasound A23, NYAL 300 and 600 (yes Im that old), Bell Labs, my favorite being Kinergetics KBA 75 class A, and plenty more that I cannot recall
Additionally, multiple class D amps; PS Audio, W4S, Emerald Physics 100.2 SE monos with upgraded fuses
Ric’s EVS 1200 is the only one that reminds me of the KBA 75
1200as1/2 modules have their place, and it isn't in what many consider high end audio. Tweak it as much as you like, it won't help anyone looking for something exceptional. As I've mentioned before, there are just too many people buying them and re-selling after being disappointed with the results. Like anything else, you get what you pay for, and the 1200as1/2 is no different in this regard. They are good value for what they cost ($250.00), but don't expect them to be anything more than that.
The stock 1200AS2 module is good. Modified (14 mods done to each board) and monoed (two 1200AS1 modules) and with state of the art implementation, it is really, really great. If you have not heard the module stock or modified then you know nothing of what it sounds like. You can show all the graphs you like, but without actually listening to the modded amp you have no idea what Tweak 1 is talking about. This is not a guessing game. You have to hear something to know what is does. Again, the stock module is good......but mono super modified boards in tricked out chassis and implemented with super tweakism brings another whole level of transparency, dynamics and musicality. But only those who have heard....know. No one else knows anything.....just righteous guesses.
"There are some class A amps I like a LOT less than my last Class D."
But the question is are there any similarly priced class D amps as good as many good e.g. $2-5K solid state class A amps for those of us who love the typical "class A magic"?
Couldn't agree with you more George, @tweak1 really doesn't get it. Here's a hint at how NOT so good these modules are - just take a look at the number of sold/expired listings for 1200as in hifishark.com to see the staggering number of amps using 1200as1/2 boards being dumped. What can you really expect for a module that costs $250.
You just don't get it tweak, this is why many find the upper mids/highs objectionable on Class-D, why would I want to listen to an amp with this much phase shift already 25 degrees! at 2khz, and it get's progressively worse all the way up to 70 degrees!!! at 10khz. https://ibb.co/VYHFHsQ
I have one on order (Video below). I’ll let you know. I’m coming from a Signature Series 6005 ATI with 300 watts all 5 channels driven ..Pretty impressive video
I will say I was much less disappointed by the Vivace amps than I was the Kii speakers.
The Kii are like listening to music with surgical ears, sucks the life out of the music, they have no soul, or musicality or harmonic structure to whatever is being played.
Like anything that's been though a DSP room/xover/eq with mutli amp class-D active speakers same deal.
"we decide to choose a feeble-bodied person who, on top of that, is encumbered by various diseases. Having made this decision (which is a priori improper) we start justifying it to ourselves and others by citing the great state of our medicine, which is capable of curing many ailments."
With the previous amps I mentioned, there simply wasn’t enough bass or mid-bass with the KC IIs. I have 2 SVS powered subs (Plus and Ultra), which I used throughout. The subs were a band-aid and were near impossible to blend. Awhile ago I decided to turn them off. Ahhhhhhhh. Reminded me of my Magnepan 3.5Rs seamlessness, but lacking bass, which is why I bought the subs. The KCIIs were a good 6 ft from the front wall. I decided to move them back, settling on ~ 4-5" farther back, and whamo, solid bass with a rich mid-band. The EVS 1200 is that much better
Hey @jdl57 - I have heard the effects you are talking about in a number of hotel rooms. It was poor room acoustics.
This was in a large conference room, much bigger than any room would be in a normal house. The speakers they were using was the Sigma Acoustics MAAT Vector XAC. They weigh 750 lbs each. I doubt the room had any effect on the sound at all, there were no close walls to reflect anything except for the one behind me. The ceiling was probably 20' high.
I specifically wanted to hear these amps and the Kii speakers since I had heard such glowing reports about both of them. I will say I was much less disappointed by the Vivace amps than I was the Kii speakers.
Regardless of how well designed the amplifier is, there will be loads with which it will not mate well.
Which is true of all amplifiers. The output impedance of amps without any output filtering at all is far more complicated, and the output impedance of tube amps is RL as well.
Which goes back to my original point that Class D amps are not stand outs in output impedance anymore. You have to listen for yourself.
There are a lot of tube amps which do poorly with ESL speakers, for instance. Linear SS amps tend to do better, but not in every case. Class D is somewhere in there. Depends on the specific implementation. Despite this, there are a number of audiophiles who end up running tube amps with ESl's. Technically I'd be surprised if the Class D amp didin't measure better.
It is prejudicial to be comparing Class D in bulk with mega linear amps at all times. Lets be more realistic.
It is true that knowing both behaviors is important, however Class D output impedance is well within the range of high quality Class A/B amps with feedback.
The Class-D output filter is RLC with the speaker providing the R. However, the speaker is not just R, but also has LC components. Like all things audio, the designer has to make choices. Regardless of how well designed the amplifier is, there will be loads with which it will not mate well.
Add in loudspeakers with crappy phase response and things could get ugly in hurry.
I think of it like putting an Indy engine in my motorhome. It's got boatloads of power, just in the wrong area. Put my motorhome engine in an Indy car and it will come dead last in 500 miles, but first in 5000.
My experience with Ric Schultz’s EVS 1200 with barely 75 hours is; it is vastly superior to my previous class D amps 2 different W4S (~ 8 years ago), Emerald Physics 100.2 SEs (3 years ago), Audio Alchemy DPA-1 which I just sold to keep the 1200, and PS Audio M700s, which sounded like the DPA-1 with 2.5xs the power, which my room demands (MSRP $2999). The EVS uses 2 of the newest 600w IcePower modules, which he then does a number of tweaks to, plus other cool tweaks an Italian chassis: $2200,
Hey @jdl57 - I have heard the effects you are talking about in a number of hotel rooms. It was poor room acoustics.
IMO, one should examine the cable/speaker impedance curve when choosing ANY amplifier. Class-D can be more sensitive due to the low pass filter.
It is true that knowing both behaviors is important, however Class D output impedance is well within the range of high quality Class A/B amps with feedback.
The Class D amps I am most familiar with have lower output impedance than most tube amps, but probably not as low as some beasts like the Codas or Sander’s with their 30 transistors per output channel. :)
Keep in mind a lot of linear amps have a low pass filter on the output to prevent oscillation. Then there is the Technics amp which actually measures the speaker impedance and compensates for it with DSP. Pretty nifty.
I am just waiting for Ralph to announce his new class D amp, hoping to try or get an early prototype, owning his AB tube amps and him betting on class D I'm sure that would be something to have. We will see. He is been pretty quiet (not like others touting whatever they sell)
I have heard this amp touted as the best amplifier ever made. By contemporary standards it is not horribly expensive, but it is also not cheap. Through most of it’s range it was absolutely beautiful. I listened for a long time because the system sounded so good, although the soundstage was ridiculously huge, as were the speakers, so I blame them for that. If the harsh notes had happened only once or twice, I would have blamed the recordings, but I heard it again and again. I was actually left with great hope for Class D, but this isn’t the amp. I have moved to all Class A amps, I assume I am sensitive to switching distortion and Class A has no switching distortion. Class D also has no switching distortion, but there is a lot of signal manipulation going on in a Class D amp, maybe too much. This amp uses the much touted Gallium Nitride transistors, and is indeed state of the art. http://gan-fet.com/2014/02/13/rock-solid/#more-204
IMO, one should examine the cable/speaker impedance curve when choosing ANY amplifier. Class-D can be more sensitive due to the low pass filter.
Tweeter resonances may be exacerbated with an ultra sonic rise in the filter response due to the impedance curve.
Back in the day when dealers abounded, it was often more productive to talk rather than listen at expo/shows. An audition in a well set up salon would often be diametrically opposed to the show horror.
O.K. I just got home from the first day of the Rocky Mountain Audio Fest. There were two things I was excited to hear: the Kii speaker system and the AGD Vivace amps. The Kiis were a non-starter. Although I didn't do a long audition, I didn't like what I heard at all. They are internally amplified with Ncore amps. The Vivace amps ($15,000/pair-mono) however, were very close to changing my preconceived ideas of Class D. They were sweet and dynamic and very enjoyable until they got into the upper midrange/treble, think trumpets. There, they were hard and grating and generally unpleasant. I first thought it was the recording, but I continued to listen as I was truly enjoying the experience (speaker was Sigma Acoustics Vector XAC, $185,000 or so), but recording after recording exhibited the same harshness. I could have been the speakers, I suppose, but probably not. I pulled up this thread to see what others were thinking and a post by stereo5 was first with the same complaints I had. Class D is still in it's infancy and after today I have great hopes, but it's not there yet.
It's about matching technology to assemble a HiFi system.
I've been a HiFi'r since I was old enough to manipulate the arm on my Dad's Bogen/Lenco in the mid 50's. Over the decades I've heard many 10s of amps with the latest buzzword technology. Not all moved the ball forward in the context in which they were heard.
I have TC-50, BiWired and recapped, and tri-amped LFT-8b. Both speakers are renowned for their phase coherency, a property without which I cannot listen. AND a long list of absolute failings.
I have 4 amps: Rotel bipolar, NuPrime ST-10 Class D, PrimaLuna Prologue 5, and a pair of VTA M-125s I reworked. Each has its ±.
Depending on program material AND time of year, each trounces the others. ALL present an excellent and engaging sound stage.
As Ralph can attest, there are 1001 details to get right, some of which are diametrically opposed. Each has it's foibles. Some genuinely beautiful boxes have no soul in some systems. AND all can be severely compromised with poorly mated cables and companion components.
The proof of the pudding is ALWAYS in the eating. AND you must eat the whole pudding!!!
This is the heading to this thread, kinda makes you think, does he believe his the new Messiah to lead the linear amp lovers out of Hades and into the garden of Eden?
And it's a common theme to every Class-D thread he starts up, to me it's like he's looking for reco or even consolation maybe.
Yet he doesn't seem to want to embrace the new GaN Class-D Technology which will rid the sins of the old Class-D technology.
What I like most about this thread is the clear difference between those willing to give Class D a chance and detractors.
Those who are neutral to positive are talking about specific brands, and models and making direct comparisons with linear amps. They talk about sound quality, systems and trade offs.
Those who are against Class D are talking about tropes from the 1980's, and measurements and broad claims that become impossible to test.
My Audio Alchemy DPA-1
Hypex 400ucD
(MSRP $1995), which I've owned close to 2 years, sounds excellent to my ears, in my system; Emerald Physics KCIIs (93dB), CorePower 1800, Audio Alchemy DDP-1 + PS 5, Marantz HD CD 1 as a transport, Oppo 105 (upgraded power supply) for SACD & DVD-A, and WireWorld series 7 & 8 cabling.
I expect to have ric schultz EVS 1200 ($2200) in a couple weeks, to compare against it. And a few weeks after that I will be listening to a ~200 wpc GaN prototype
I have little doubt that the GaN will be better, but by how much, and at what MSRP differential?
"It WILL NEVER be as good as tubes,class a or good a/b NEVER!!!" As a tube amplifier manufacturer I have to disagree with this comment.
You have to it’s plain as day, because of what you have coming, if you didn’t it would be a waste of development and money, as tube sales especially otl’s and pre’s are down and you need to diversify.
Class D is in the middle of the curve
It's still like trying to make a sport car out of a cement truck.
It has yet to reach true hiend, with it’s achilles heel’s it has. GaN Class-D technology points to be able to get rid of them and give it a real shot at the hiend audio, one should have invested in it, over the old technology, as it will become the dinosaur, just as linear amps will one day.
It WILL NEVER be as good as tubes,class a or good a/b NEVER!!!
As a tube amplifier manufacturer I have to disagree with this comment. We are a tube amplifier manufacturer that is also developing a class D amp.
Our tube amps have gotten excellent reviews and numerous awards in the high end audio press; in particular they are known for their transparency and musical nature. So I'm not making this statement lightly. No-one knows the future but we do know that people make innovations. We made one and its why we have a patent application filed on our class D amp; I am of the opinion that class D has a lot to offer in the transistors vs tubes debate. IOW, I wouldn't say 'NEVER'... There is a thing called a 'technology/performance' or 'innovation' curve. Its generally the shape of an S. At the beginning, when the technology first appears, a lot of time and money goes into its development, with small increases in performance. As the tech gets sorted out, with small amounts of time and money much larger performance increases occur; then as the tech is mature (think transistors and tubes here) then larger amounts of time and money yield incremental improvements. Class D is in the middle of the curve, so its still possible that smaller companies like mine are able to make big improvements. There are a lot of players in class D so 'never' seems dubious to me.
The only experience I have wth full range Class D amps was in an sudio shop listening to a Rotel Class D amp driving Vandersteens. They sounded nice, but I wasn't there long enough to really discern their sonic features. The Class D amps in my subs sound great, however, so at least, for me, they well serve a limited bandwidth duty cycle.
@tweak1 I never receive notifications about new posts. I recently noticed the autocorrect features of the forum posts no longer work. And the search engine functions of the forum are now disabled (zero hits as search results).
Sorry for the duplicative (and now-deleted) posts. System error with the site and not the user. 😬😬
My previous post is made against a backdrop of using a Spectron class D amp to drive Dunkavy SC-IVa’s. So I readily accept using a single-run of IC’s from the preamp to the class D amp.
@erik_squires The Schroeder Method for parallel IC’s works, but strongly recommended against its use with class D amplifier topologies owing to the increased bandwidth of signal transmission of the IC’s into the realm of the switching frequencies of those designs. I think folks should (and do) evaluate all component changes in the context of their entire system with respect to SQ improvements.
Doug’s opinion (as shared by many, including me) is that the improvements in SQ afforded by parallel IC’s can be equivalent to exchanging a component elsewhere in the system. I’m not so certain that the use of parallel IC’s over single-run IC’s actually trumps exchanging a component, per se. But using a non-class D amplifier topology might enable some to improve the overall SQ of their system with use of a full loom of parallel IC’s from source to final amplification.
For my two cents worth, I am reviewing a new SPROUT100 from Scott McGowan at PS Audio. This is the second round of testing and reviewing. The first time I found the sound rather anemic, even with their Bass Boost employed. In the interim, I obtained the Infinity Intermezzo 1.2s subwoofer, and now everything sounds better. The sub doesn't require the SPROUT to try and make Bass, and it asppears to free up ther Mids and Top-end.
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