Class D amps

I know Class D power amps are used in car audio applications. Why not for home audio power amps? Thanks.
Actually, there are a number of Class D amps available for Home Audio. Bel Canto, for example, offers a number of Class D amps. I believe NuForce does so also. There are others as well.

The real issue has been acceptance of Class D by audiophiles. The amps have a mixed reputation -- some listeners enjoy the detail Class D amps reveal in recordings, while others do not like the hard edge many Class D amps add to higher frequencies. I, for example, briefly owned a Bel Canto amp -- I didn't like the sound at all. But it is a matter of taste, so YMMV.
It really is YMMV. I got a pair of Wyred 4 Sound class D monoblocks about 4 months ago and they are the greatest things I have heard in my system thus far. IMO they are extremely transparent and convey what is exactly on the source material which to me is the highest complement you can pay a amplifier UNLESS you want your amp to color your music. I don't have any issues with its high frequency performance and they sound just as extended as any other amp I have heard in my system. The alleged high frequency issue kept me away from class D for years until I decided to hear it for my self.

I suspect the high frequency issue has more to do with impedance matching between components rather than something that it is intrinsic to all class D amps. Alot of owners of tube preamps don't like the tube/class D combo. Class D amps tend to get their best reviews when paired with low output impedance solid state amps.
Nordic587 did you just come out of a coma? This site and others are full of comments on Class D amplifiers used in 2-channel and home theater applications. Some of the brands are very well known.

Obviously you have not been paying attention so I will give you one piece of advice. Beware of postings that do not identify which iteration of a product is being discussed and under what conditions. For instance the person posting may have heard the first generation of a product that is now in its third generation. That is particularly important for Class-D as that technology is still evolving.
Nordick587 - it must've been long coma, since this partial list of companies making home Audio Class D was compiled in 2008:

Acoustic Reality www.acoustic-reality
eAR202, etc (ICEPower)

Aivin www.aivin
DT300 (www.aivin) (Tripath)

Analog Research Technology www.analogresearch-technology

AudioArt (NL) www.audioart
Van Medevoort MA240 (Hypex UcD)

Audiodigit www.audiodigit
MC 8x100 (Tripath)

AudioResearch www.audioresearch
150.2, 300.2, 150M (Tripath)

AV123 www.av123
X-Empower, xAmp (prelaunch (
(Philips class-D?)

B&O www.icepower

BelCanto www.belcantodesign
Evo (Tripath) eOne (ICEPower)

Bertram www.audiokabel

Carver www.carverusa
300.2, 700.2, 1200.2

Cary Audio www.caryaudio
A 306 power amplifier (www.caryaudio)

Channel Islands Audio www.ciaudio
D100, D200 (Hypex UcD)

Chapter Audio www.chapteraudio
Couplet Power Amp (proprietary WMP class-D)

D-Sonic www.d-sonic
Magnum (www.d-sonic) (ICEPower)

DIYCable www.diycable
Exodus (www.diycable) (Hypex UcD)

Egosys www.egosys
Audiotrak DrAMP (www.audiotrak) (Tripath)

Elan www.elanhomesystems
D1200, D1600 (12 and 16 channel power amps, Tripath)

Electronic Visionary Systems www.tweakaudio
EVS-2 (www.tweakaudio) (ICEPower)

Flying Mole www.flyingmoleelectronics
(proprietary class-D)

Gilmore Audio www.glacieraudio
Raven, Raptor, Dragonfly (www.glacieraudio) m/ch (looks like ICE)

Halcro www.halcro

H2O Audio www.iceh2oaudio
M250, M500 (ICEpower)

Integra /Onkyo www.integrahometheater
DTA 9.4 (www.integrahometheater) 7x120W 8Ω

Jeff Rowland www.jeffrowland

Jjaz Audio www.jjaz

Kharma www.kharma
MP150 (www.kharma)

LC Audio www.lcaudio
Predator SE (www.lcaudio) (ZapPulse)

Marantz www.marantz
Opsodis ES-150 (www.marantz) (D2Audio) 2ch virtual surround

Medius [DK] www.medius
A II, A III (www.medius)

MG Audiolabs www.mglaudiolabs
Symphony (www.mglaudiolabs) (Hypex UcD)

Midgard Audio www.midgardaudio

MindCraft (NL) www.mindcraft
Media Amp One (www.mindcraft) (Hypex UcD)

Murano-Audio (TW) www.murano-audio
P500, P1000 (ICEPower)

NHT>Power2 (, Power5 ( (ICEpower)

Nuforce www.nuforce
Ref 8, Ref 8b, Ref 9 (nPhysics proprietary class-D)

NuVo Technologies www.nuvotechnologies
NV-P2100 (www.nuvotechnologies)

Onkyo www.onkyo
A-1VL, A-9755, A-9555 ( (?)

PSAudio www.psaudio

Red Dragon Audio www.reddragonaudio

RedWineAudio www.redwineaudio
Clari-T, Lotus (Tripath)

Rotel www.rotel
1077 (7x100), 1092 (2x500) (ICEPower)

Sharp www.sharpusa
SM-SX1, SM-SX100

Brontë (Tripath)

TA-DA9000ES, TA-FA1200ES (www.stoneaudio) (S-Master)

Spectron www.spectronav
Musician, Troubador (int amp w digital inputs)

TactAudio/Lyngford www.tactaudio www.lyngford
Millennium & others (Equibit)

TEAC Esoteric
AZ-1 pre-main (translated (babel.altavista))

ThetaDigital www.thetadigital
Virtu PowerDAC (www.thetadigital) (Zetex class-Z)

UniwaveTek www.uniwavetek
Anaco II

Yamaha www.yamaha
There are and many are quite good and worth consideration.

The Bel Canto ref1000m monoblocks I use are one good example. These are competitive soundwise with some of the best SS and tube amps I have heard and the combination of small size, weight and low power consumption along with bleeding edge power output and solid current delivery is hard to beat.
There are class T(TriPath) that I personally prefer over the class D.
Being a studio tech hobbyist, got used to clinical and clean sound to evaluate a recording quality. Learned to appreciate Sunfire class T amps for these abilities of thin details, instrument separation, speed and muscle power.
Amps such as W4S have high enough impedance to be driven by any tube preamp with ease. I would though recommend to use fully balanced tube preamps.
"Alot of owners of tube preamps don't like the tube/class D combo"

I have a tube pre-amp and like the combo.

The thing is, you have to pick a Class D amp that is designed to work with a tube pre-amp (ie higher input impedance). Same true for other SS amps in general.

For example stock IcePower Class D modules are 10K ohm input impedance unbalanced. Not great for a tube preamp. Older BelCanto Ref1000 falls into this category. Many lower cost Class D amps do as well.

Wyred 4 Sound and newer (and more costly) Bel Canto ref1000m using similar 10K ohm stock Icepower modules are designed to work with a tube pre-amp. Input impedance of Wyred is ~ 64K ohm I recall. BC ref1000m is 100K unbalanced and 200K balanced.
The digital amp company makes a really good class d amp. They have a model called the 4800a which is being discontinued and the cherry plus is also a very nice amp from this company, I think if you are considering getting a class d amp you should put them on your short list, just my opinion, Kent
No, didn't come out of a "coma." I am new to audigon. I have only seen brief mention of Class D amps but never did any lengthy research.
There is a ton of info on A'gon about Class D amps.

One of my favorite topics.
I'd suggest doing a search before asking questions.
No reason to beat up Nordic, we should welcome newcomers to the forum. Two comments on postings so far:

(1) Class "T" is really a class "D" amp. Tripath was one manufacturer of chips for the technology, and ARC called their amp a class "T" simply because they used the Tripath chip for their 150.2, 300.2, and 150M amplifiers. When Tripath went bankrupt and the chips were no longer available, ARC discontinued those models. The new ARC class D amplifiers, their "DS" series, use in-house developed chips, so the class "T" designation no longer exists.

(2) As was mentioned earlier, the combination of tube preamp and class D amp is primarily a matter of synergy. In my case I use all ARC components, and, at least to my ears, the combination of an LS-17 tube pre feeding a class D 150.2 and Maggie 1.6QR speakers, sounds very good. Of course, ARC components are made to mate well with each other.

Please don't let the rudeness exhibited in some posts scare you away from the forums...plenty of good folks here willing to help. I don't use D-amps but I have a friend who replaced his older VTL tube amps with a great pair of D-amps he created from a kit (I think has a fan site) and I gotta admit they give the VTL's a run for their money and certainly beat them in terms of speed and dynamics. Given the kits were sub $500, I think we'll see more great D-amps to come. I tried the Bel Canto M1000's but they were a bad match for my system.
New to Audiogon since April 2010 isn't new. And the initial post was not as much a question as a statement that was not true.

I would be more tolerant of an innocent question compared to an inaccurate statement. There is already too much misinformation and repetition on this site.
Some of you guys (gals maybe-not you Elizabeth, you're cool) need to learn to be nice. I'll bet you'd have better manners if Nordic587 asked you face-to-face. Jeez.

I've been a music lover and hifi hobbyist for almost four decades and it still seems like there are sharks lurking to pounce on my posts sometimes. I'm a big strong guy and I could probably kick your butt.
Add to your list 'International Rectifier'. I have one of 'em out in the garage needing a power is one of the development boards given or sold to people contemplating using them in OEM applications.
I may be the only other "gal" lurking around here apart from Elizabeth and I'm pretty darn nice! LOL!

Actually the question posed by the OP is of interest to me as I have the Wyred for Sound dec 2 and when my old Classe gives up the ghost, the Wyred integrated amp would be of interest. When I first began reading about amps and such years ago, no one ever spoke of Class D so I'm still a bit foggy about what it means, some of these posts have been clarifying.
It is very simple in concept and offers a very high efficiency but has proved to be quite difficult to implement without running into problems more conventional amps don't face. Which is why amps which should theoretically be small and cheap end up as big and expensive as conventional amps. As you can see from the above comments opinion on the sound quality is really divided.
Magfan, I remember IR but there are many others. The list is old.

As for rudeness, it would be very rude of me to ask on this forum if TT or tubes still exist, displaying total ignorance, especially when information is on the cover of most audio magazines and internet. One would have to make serious effort to avoid knowing that.

My Rowland 102 comes from the first generation and sounds incredible. As I understand it, there is very little difference between two generations and the reason for "big improvement" is to make easier for some people, including well known audio critics, to remove foot from the mouth.

Break in takes very long with class D and my amp started sounding much better (smoother, more refined) after 400 hours. The issue is not if class D amps are the best but rather if they are good for the money. Not too many amps around $1500 have such immediacy, transparency, smooth highs, liquid mids, and iron fist controlled lows as my 200W Rowland 102 - smallest of the Rowland family.

I agree. My Hypex UCD400HG with H x R monoblocks I built took well over 400 to bloom. More like 600-700 hrs. Until that point they were okay, somewhat flat and lacking air.

Now they ere phenomenally 3D, tons of air, huge soundstage and incredibly detailed. Best amps I have owned.
Fidler, I'm familiar with Hypex modules. Hypex kits were very nice with low inductance slit foil electrolytic caps and big satisfaction of building it yourself.
I have the ARC DS450 D class amp. It is mated with ARC's LS27 - tube line stage. This combo works beautifully.

No one has mentioned the Kharma MP150s which (admittedly awhile ago) won Absolute Sounds shoot out of class D amps. I have a tubed Cd player with volume control (EAR Acute) driving the Kharmas directly. It is absolutely wonderful sound -- the best I have been able to produce in my system in over fifteen years of effort. I also very much liked a number of the Bel Canto amps previously mentioned. I have had better results with system building using Class D than any other kind of amps, and I have tried quite a few including some pricey ones.
When you mention 400 hours, do you mean music needs to be playing through during those 400 hours?

Or, will simply leaving them on for 16.666666666666667 days (400/24) be sufficient to break in / burn in?

Or in the case of 700 hours; 29.166666666666667 days straight?

If music or pink noise is required for proper burn in, what do you use as source if one does not have a tuner?

I would be very reluctant to have any CD player, Computer, or TT playing music 24/7 for 16 to 29 days straight.

For the aforementioned reasons, I abandoned class D in favor of a class A Hybrid Tube Integrated, which sounded impeccable right out of the box, and continues to sound just as impressive.

And, in hind sight, because of the long time required, I may have abandoned too early; I was enamored by the sound at first but got increasingly frustrated in the long term.
Mapman, Thanks for saying what I meant to say. Reading your posts and the post of a few others here on A'gon is what convinced me to get over my fears of trying Class D and I am glad I did. After hearing nearly 10 different amps in my system I have nipped the upgrade bug with these new amps.

I think its funny that to my ears class D sounds nothing like what its naysayers claim. It has really turned me off to so called professional reviews. The best thing to do is just hear the equipment for yourself.
Yes, I recall the arc switching amps to be designed to work well with tube preamps. No surprise from a company like arc that is an icon for tube gear.
Eric... thanks for posting that!! I have been debating on jumping on the class D bandwagon in the next few weeks & have been wondering how to break it in. So what's the verdict, just having the amp on or does in need music/noise through it?

Kinda funny... I have old Adcom car audio amps & the local audio shop (getting ready to do a install again, Morel sub - Hertz mille components & Adcom) & the shop wants me to go the class D route (JL HD's) in place of my old adcom stuff which I just can's get myself to do. Looking for a new/used amp to power my main home speakers.... & class D is at the top of my list. I am leaning towards the wyred 1000w amp. Threads like this help me make my decision.....

You got it.
As in everything implementation can mean success or not. Generally speaking, Class D amps have small size and little heat relative to the power they produce. Again, generally speaking, it is difficult to produce a very refined Class D amp that can compete in the higher echelons of Audiophiledom because of of their difficulty in the mids and high end of the audio spectrum. Vandersteen uses Class D amps to drive only the lows thus eliminating the problems and taking advantage of the benefits of Class D amplification. I believe there are many Class D amps that are incorporated to drive subs.
Class D amps aren't necessarily small, and/or at least not lightweight.

My Hypex amps I built have (1) 500va toroidal transformer per side, all Neotech solid core wiring, upgraded IEC, RCAs and binding posts. They are not light. And to answer the question above, my amps took hundreds of hours of PLAYING time to really shine.

I agree with Ciphercomplete. My amps sound nothing like how a number of professional reviewers have described them. I think their criticism is primarily snob appeal and protection of the well-established, high-end amp manufacturers who are clearly threatened by more efficient and cost effective technology. I can afford virtually any amp I want, but so far, I have not been tempted to purchase any other amps.

Hypex amps are the best I have had in my system (only after lots of hours) and Hypex has also announced a new amplifier, NCore, which they contend will meet or exceed the SQ of any SS amplifier technology available at any price. Time will tell whether this is simply marketing or if Bruno Putzey, has indeed, pushed the envelope on Class D.
Thanks to those who responded to my query with decency. I guess the all kinds to participate here no matter their apparent lack of manners.
Unsound: I wasn't aware that Audigon requires the step you mentioned in your "response" before posting. Didn't see it in the rules. I appreciate the intelligence and helpfulness of other responders. Those seem to embody the spirit of Audiogon.
It is important to carefully research any question before posting it to this forum as many here live on the edge of
emotional sanity, and asking a seemingly uninformed or naive question can push some members into a frenzied and uncontrollable episode of sweaty manic responding creating posts written in a spirit of self righteous indignation crammed with every scrap of vitriol laden minutia their frazzled brains can summon to the page. Nobody needs that.
If you look up the word rudeness in any dictionary you will not see any coreallary to "lack of awareness" or "naïveté ". A little too much time spent alone in the man cave, perhaps?

If we do not treat newcomers with helpful, patient kindness, this hobby deserves to die anyway.
I just typed "class D" into search engine and got 300 threads in response. It is a very good tool for novice. It is not mandatory but rather good manners.
Thanks To Wolf_garcia and Kijanki!
I meant Thanks to Wolf_garcia and Vhiner. I will have to look up "good manners" in Audiogon's rules for use. No, better yet, I will contact the Audiogon Admin and ask under what if any circumstances it is permissible to ask questions if the answers to said posting are addressed anywhere else in the archives of Audiogon's entire history of subject matter on the issue of audio. Hmmm... don't seem to recall reading that restriction when I signed up. I will continue to post queries at will. To those who wish to control others, I am not fair game.
Nordic587 - Like any other class of amplifiers there are better and worse class D amps while everything depends on system synergy. My small class D amp is good for the price but in different price range you'll find many great class D amps like mentioned Kharma. Class D is this strange thing that sound at the same time great to some people and horrible to others. One limitation of class D is bandwidth related to switching frequency that is limited by speed of available Mosfets. 65kHz bandwidth of my amplifier causes about 20deg phase shift at 20kHz and therefore improper (shift) summing of harmonics. You can still find much higher bandwidth in some other class D amps like Spectron Musician III.

Class D used to be very primitive sawtooth modulator that converted voltage level to duty cycle (and therefore average value after filtering) with very limited bandwidth. Todays class D is much more sophisticated and resembles high power Delta-Sigma A/D converter byproduct. Principle of operation is well known and accepted (SACD is exactly the same thing - recorded PWM that just needs filtering) but implementation is constantly improving. I would rather live with existing limitations instead of TIM distortion (and therefor bright odd harmonic) produced by many class AB amps.
Fiddler....or they are not competetive in their price range...are not selling. Try Ayre, Audio Research, BAT, etc.,
Nordic587, it was merely a suggestion.
So many Designs. So my implementations.

So little time.
You would think that audio enthusiasts would welcome the chance to talk about , explain or weigh in on any question no matter how simple or naive. Strange behavior from hobbyists. But Wolf explained it perfectly. I don't ask anymore.
Stringreen, I have owned 2 of the 3 you mentioned and if I understand you to mean that Class D can't compete with them, I would have to respectfully disagree. IMHO, of course. Believe me, if my current amps couldn't cut it, I would do what I have done countless times in the past - spend gobs of money chasing my Holy Grail. I'm not saying the UCD HG with H x R are the Holy Grail, but I will say I have enjoyed them as much as anything I have owned.

And If I am not mistaken, the Kharma amp that someone referenced here as being exceptional uses the Hypex UCD modules, albeit with a tremendous markup,

If I completely misinterpreted your comments, my apologies in advance.
Uh oh, I think I did misinterpret your meaning, sorry.
I think the work Henry Ho of H2O audio is doing with ICE amps and massive analog power supplies sounds very very good. A few of our local members have had the pleasure of hearing his amps in my system a couple of different times (with tube pre) and they sounded splendid. FWIW
12-17-11: Wolf_garcia
It is important to carefully research any question before posting it to this forum as many here live on the edge of
emotional sanity, and asking a seemingly uninformed or naive question can push some members into a frenzied and uncontrollable episode of sweaty manic responding creating posts written in a spirit of self righteous indignation crammed with every scrap of vitriol laden minutia their frazzled brains can summon to the page. Nobody needs that.
Wolf_garcia (Threads | Answers | This Thread)

Amen to that, as has been shown by my thread on >speaker cable vibration. You would have thought I started a thread on the merits of golden parachutes the way the Occupiers moved in.

12-17-11: Rok2id
You would think that audio enthusiasts would welcome the chance to talk about , explain or weigh in on any question no matter how simple or naive. Strange behavior from hobbyists. But Wolf explained it perfectly. I don't ask anymore.
Rok2id  (Threads | Answers | This Thread)

Rok2id, I seem to recall you were 'irritated' that I had discovered and posted about music-borne vibrations in speaker cables. I swore that day to be sensitive to you with any future posts. But you've obviously turned over a new leaf. I'm touched. Misty, actually.

To the OP - no shortage of d-bags on this forum. And we wonder why "audiophilia" isn't accessible to more people. Some people here wouldn't know how to lighten up if they took an enema full of helium.
"Some people here wouldn't know how to lighten up if they took an enema full of helium."

Now this is funny! I guess Wolf was thinking along the same lines when he called them 'elitist gasbags?' hahahahhaha
"I swore that day to be sensitive to you with any future posts"

Please define 'sensitive'.
I will tolerate non-elitist gasbags.
HEY!!! I resemble that remark.