Which Class D Amplifier? PS Audio, Ghent, Nord, Merrill or other???

byington711,

     If you're still following this thread I have a question:
    From your 1/4/19 post on this thread, I'm not sure if you own the stereo PS Audio BHK 250 or the mono block 300 amps in your system.   
     Regardless, it's my understanding that the PS Audio BHK 250 stereo and 300 monos are class AB amps, not class D amps. 
      Therefore, neither have the usual class D benefits of compact size, low weight, low operating temperature and low electricity consumption,  Both of these amps are quite large (at least 17.1"W x 8.7"H x 14"D), quite heavy (83-100lbs), have high operating temperatures  and consume considerable electricity (at least 175w @ idle and 850/1.600w @ full power at 8/4 ohms). 
     By listing and suggesting these amps on a thread titled :Which class D amp?....", my concern is that some might mistakenly believe that the PS Audio BHK amps actually are class D.
      Can you please clarify and definitively confirm the PS Audio BHK areps are both class AB?

Thanks,
   Tim

One thing I should point out: I have no explanation but my Class Damps sound pretty mediocre unless warmed up for about 72 hours. 

If you are auditioning amps cold, or recently moved, and you don't like the sound, that could very well be why.


Do use your own ears.  Don't think that Class D means zero warmup time.

Arctikdeth, Perhaps you should audition some other D amps before deciding its lacking.  Have you listened to the Anthem M1's?  

As WSHS31a stated, pros seem to have a wide range of experience in this equipment.

My brother is a long time Audio/Video engineer/producer with a lot of experience with home audio gear.  I had not seen him in several years and he came for a visit last summer.  He wanted to hear my M1's fed into my Bryston Signature Model T mains with three subs place around the room in a 270 degree layout. (subs are Axiom/Bryston).   I have around 6000 watts in total here which includes the 4000 watts at 4 ohms (dedicated dual 240V/15 amp feeds) into the main speakers.  My brother was blown away; he used to work with many national bands who would tour at his college and he said my living room which is around 10,000 cu. feet in size sounded better than the live venues he worked.   He loved the Class D M1's.
I am going with his opinion and experience :)

Heard, auditioned, gone!
A or A/AB still the best sound.
D is shallow. Heard many, no life, music sounds veiled, shadowed if this makes sense?

my class AB AND H (sunfire) rock any D stuff.
sorry, my ears are good

This is an interesting discussion.  I usually just lurk but I think I have a bit of a unique perspective.  Not only am I long-time audiophile but I am also the "sound guy" and tech for a popular band around my parts.
Class "D" has been used for years in the PA systems for sound reinforcement and the companies that produce that equipment have a lot of experience.  The designs have been refined and, frankly, the good stuff is at least as good or better than the stuff sold to "consumers." No longer should pro quality PA amps be considered the poor cousin to consumer equipment.

Personally, I use a pro Yamaha PA  class "D" amp (around 1000 watts per channel) to drive my electrostats.  It sounds great, is ultra reliable and even looks good. I has a built-in limiter and all kinds of speaker and amp protection. Pro equipment like this is designed to be ultra-reliable. I've used many kinds of different amps in the past - both pro and consumer (I'm a lucky guy since I have access to many) and the Yamaha has been my favorite now for several years.

There are lots of choices that sound great as well made by Peavey, Crown and others.  The newest Peavy IPR2 amps, for example, are incredibly light and powerful.  The IPR2-7500 cranks out over 2000 real RMS Watts both channels driven into four Ohms and weighs in at around 15 pounds. Just be sure to use a 20 Amp ac line to power it.

Just my two cents.

+1 for D-Sonic.  Great build quality, no-nonsense design (some people see it as a bad thing, but I love black equipment with blue LEDs on them)!  Ton of power, they are awesome on Magnepans, which are very inefficient.

Current Class D has come a long way compared to a few years ago, who wouldn't want good amplification which is more efficient, takes up less space, runs cooler... and is possibly better value depending on which manufacturer you choose.

Yes Class D is improving as the high tech elements of the modules improve. Class D amps are like DACs in this regard. A current Class D amp will be much better than one from 10 years ago. 

I have some older Bel Canto units (before the Black series), pre and amp that have been superb. Super low noise, lots of oomph, sweet midrange on my Merlin VSM's, and I can leave them on all the time!

Consider the amps made by Wyred for Sound.  I use a pair of SX-1000 in a bi-amp configuration with a pair of class AB amps driving MBL speakers.

I have owned/reviewed:
Acoustic Imagery Atsah (NCore 1200)
Audio Alchemy DPA-1 (?)
Nord One Up (NCore 500)
PS Audio Stellar S300 (Icepower)
Rotel RMB-1565 (Icepower, currently my HT amp)
Emerald Physics EP100.2SE (?)
Wyred 4 Sound ST-500-II (Icepower)
Wyred 4 Sound ST-750LE (IceEdge Icepower)

The Wyred 4 Sound ST-750LE is still in use while the rest have found new homes.

Happy listening!

Regards,
JerryS
10audio.com

I have a system with a pair of Sonus Faber Amati Futura and a full loom of Nordost Valhalla.
My first amp was Audio Research DSI200. A Class D amp with a somewhat warm and rich sound. Nice if you are looking for a slightly "tubey" signature.  
I then switched to Jeff Rowland Continuum S2. This is has a cooler presentation with slightly better bass control. It was good but I felt like it lacked "soul". 
So I left the Class-D world and found the magic in an A/B called Gryphon Diablo 300. IMO this amp is way more organic and soulful. The bass control is miles better than the Jeff Rowland despite it had 2x800 W. For some reason it was not the perfect match for my speakers who venture under 3 Ohm in the bass region. I always thought I had a "bass problem" in my listening room. It turned out the solution was getting a better amp. 

As Noble 100 stated in his experience with a quality Class D amp, I fully concur; its the lack of noise, extremely low distortion and amazing detail that struck me right off.  

And since I am such a 'green eco' type, I don't feel guilty with running these mono's for hours on end as they are so efficient.

Here is an interesting point of note:  my Anthem M1's do not come with a schematic which I wanted to read with an engineer friend of mine.  I called Anthem and asked if I could get a copy and they told me no.  They will not supply any schematics to the public, only to authorized service technicians.  I asked why they have this policy and I was told that they invested millions of dollars and years of time developing the M1 design and they consider it proprietary in all respects.  I can understand this philosophy and I don't blame them.

I was interested in how they handled the mitigation of high frequency harshness which inexpensive Class D designs are known to suffer.  The M1 is so smooth that it's uncanny.  And if anyone is interesting in looking online at some of the YouTube videos on it, you'll be quite impressed with the copper heat pipes which are liquid filled (some type of alcohol I am told) which draw the heat through convection currents away from the finals to the heat sinks on the side of the amp.  These amps feel like Capt. Kirk's USS Enterprise to me :)

Must agree with "frame1" 

"Try ClassD Audio. Excellent product and value. Tom, the owner is great to work with.
http://classdaudio.com/"

I've got the ClassDAudio SDS470C, which sounds virtually as good as all the other amps I have, or have heard (e.g. Atma-Sphere M60's, Parasound JC'1's, etc.).  Though my Linear Magnetic 219ia may have a bit more "ethereal" tube sound, which presents a very "real, live" sound.  

And... his amps are an unequaled value.  

Slimpikins5 stated:
"Fast forward: I was further piqued now about Class D and wanted to get into something much more advanced, so I picked up a pair of Anthem Statement M1 Class D mono blocks which run around $7K for the pair. These babies put out 2000 watts per channel at 4 ohms (my speakers) and all I can say is; holy moly I was blown away at how much better they play than the Class A/AB amp I have been using!   Far more dynamic range, better soundstage and imaging, no high frequency harshness at all, just super clean floor shaking output."


     I find your description of the improvements you hear from your Anthem Statement M1 class D amps,  "far more dynamic range, better soundstage and imaging, no high frequency harshness at all, just super clean floor shaking output",  to be very similar to the improvements I've experienced upgrading to the D-Sonic M3-600-M class D monoblocks.   
     I just wanted to add a few additional comments about my experiences for the benefit of readers who haven't yet listened to a good class D amp in their systems.  I suspect my comments will ring true to all owners of good class D amps, also.
      I was initially struck by how quiet these amps are.  Music just seems to emerge from a dead silent background with absolutely no background noise that is verified by their excellent Signal to Noise Ratio measurements.  I believe this, along with extremely low distortion measurement levels, combines to result in an exceptionally detailed and transparent overall presentation that also allows for a sound stage illusion that is remarkably 3 dimensional and stable ('in the room' sensation on well recorded tracks). 
     Another quality that is quite obvious upon first listen is the overall neutral presentation.  I was actually a bit concerned about this quality since I thought I preferred a more flavored sound tilted to the warm side of the spectrum.  I had used a VTL 2.5 tube preamp (with NOS Mullard tubes swapped in) expressly for this purpose in my system for years.  After careful comparison with and without the tubes in my newly class D amplified system, however, I discovered my music sounded just as sweet and without any hint of harshness without the tubes. 
     I thought my tubed VTL would always be in my system and I had even  just bought an expensive quartet of replacement NOS Mullard tubes for it.  But I felt I had to trust my ears, so I sold my beloved VTL to a buddy and have no regrets.
     I think the above descriptions by slimpikins5 and myself are a good summary of what to expect from a good quality class D amp.  Just remember that there arevariances in the performance quality of class D amps just like all other amp types so try to audition any candidates in your system prior to deciding. 
     But I'd still prefer to know your needs, system and budget before offering specific amp suggestions. 

Tim
     

I am loving this thread! I did months of exhaustive product research on class D amps last year, going back 4-5 years, all in search of musically effective (as well as powerful) class D amp options for my extremely crowded desktop (literally nowhere to put a >150WPC class A/B amp).

I ended up buying a used Wyred4Sound ST-500, and I must say, this thing has been one positive surprise after another. I never had top-of-the-line SS amps (my big amps were tube; I used SS only for subs or casual systems). The ST-500 is far and away better than any SS amp I own/have owned. Perfect for this desktop, and w/more than enough power for the ATC SCM12 Pro passive monitors, which really can take a lot of power.

I'm filing away the Nord amp comments. That amp really interests me, and if I can find one used for a reasonable price, I'll get it. 

The quest for better sound goes on, even though what I have is really quite good...

Nord One Up mono amps are excellent for the price. I have a pair I will be selling

I am a Dealer who has sold quite a few amplifiers.
I am in Love with the Jeff Rowland Model 125. Amazing Amplifier.
If you have any questions, Please let me know.

Best,
Sunil Merchant.

I have the PS Audio M700s and think they sound amazing across the full range.  Have had class A/B most commonly.  Upgraded from Rotel class D most recently.  Ps audio provided much larger sound stage superior detail and imaging super tight powerful bass and smooth mid to upper end.  Light weight low heat less energy use massive power reasonable cost were my motivations.  They deliver.

If it's in your budget, you might want to look at Theta Digital Prometheus Amps (sometimes used pairs come up on Audiogon).  I had them in my system for 6 years and they performed perfectly.  Class A ratings from the hi-fi mags and impressive feedback from other audiophiles when listening to my system.  The amps are in my brother's system now and are sounding awesome there.

https://www.psaudio.com/pauls-posts/bashing-amps/

The D doesn't stand for digital. Can we please stop with the digital amp thing already? That is incorrect. There is no such thing as a digital amplifier.

Class D amps are analog!

Peachtree Audio has been producing digital amps for at least 10 years. Many variations available; many include a tube based headphone amplifier. Prices very reasonable. Great deals can be found on ebay.

PS Audio's S300 is a stereo amp and their M700 is a monoblock, so yes, they use different modules.

ACOUSTIC IMAGERY ATSAH NC500 Monoblock Amplifiers

The ATASH power amplifier is a Class D design and is based on NCore® technology from Hypex. NCore® is the name given to the first significant step up in power amplifier performance in a decade. https://www.hypex.nl/p/technology/ncore

Building on the strong heritage of the UcD design of Class D amplifiers, NCore® takes the things UcD does well and does them ten times better.

Coupled with a dedicated switch mode power supply made specifically to work with the Class D design, this amplifier not only nudges at the performance of the best linear amplifiers, but surpasses them in every aspect of sound quality.

I went to the tube side but these amps beat out any class A amp I have heard or owned regardless of price. 

Bel Canto REF600M monoblocks. I never heard a class D amp I liked until I heard these and they are superior to just about everything on the market, and an absolute bargain at less than $5K. No harshness, no digital edge, no noise, no whitish coloration, no tubey softness..... just right. Exceptional dynamics, resolution, damping. And they can drive any speakers with ease. Plus they’re energy efficient.

What’s the failure rate among various audiophile Class D amps? Is it higher than class A/B? Has it improved over time? 

ATI makes a very good class D amp. They have a linear power supply, sound great, and don't cost an arm and a leg. 7 year warranty.
https://www.ati-amp.com/AT52XNC.php

slimpikins

I haave owned 6+ class Ds oer the last decade, and owned a Parasound A23. I MHO the Audio Alchemy class D comes closest in warmth but is much more open

Try ClassD Audio. Excellent product and value. Tom, the owner is great to work with.
http://classdaudio.com/

I have zero experience with Class D amps, other than with the new Bash 300s I installed in my sub (and love).  However, just recently I read a few articles about the newest Krell Class D amps (the XD series) and they get glowing, stellar reviews - I was actually impressed by what I read (that, in itself, speaks volumes because I’m an old and hardcore analogue guy) and think you should research these before you make a decision.

Good luck!

I had been using a Parasound A51 A/AB amp which has been a very nice amplifier.  However I was very interested in Class D amps and was considering picking up something in this area as I love the idea of low energy consumption when at idle, higher efficiency and lower operational temperatures.  I was sent one of the new Parasound Zonemaster amps, granted its not being marketed as a high end piece, but at least I could try it against the A51.  I was impressed with all aspects of its performance except for the high frequencies which I found to be somewhat harsh and that is the common complaint with Class D amps which use the off the shelf ICE modules which this amp is.  But for a cheap and easy to pick up amp, it's really quite good and an excellent choice for a kid in college who doesn't want to lug around a beast and get a lot of power for not much money.

Fast forward:  I was further piqued now about Class D and wanted to get into something much more advanced, so I picked up a pair of Anthem Statement M1 Class D mono blocks which run around $7K for the pair.  These babies put out 2000 watts per channel at 4 ohms (my speakers) and all I can say is; holy moly I was blown away at how much better they play than the Class A/AB amp I have been using!   Far more dynamic range, better soundstage and imaging, no high frequency harshness at all, just super clean floor shaking output.  The finals in the amps are liquid cooled via copper heat pipe convection to the cooling fins on the side of the amps and the temperature under full load is never much warmer than ambient room temperature.  They only draw 33 watts at idle and there is no noise at all.   These are super clean sounding and I just love them.  There is no comparison to the Parasound A51 Halo amp, these M1's blow it away in all aspects.   But then again, they are almost twice the price; but I will add well worth it.

Full disclosure: I am selling two Jeff Rowland Class D 525 amps but none the less I have a great deal of experience with them:
I have used two Jeff Rowland 525 stereo amps for a few years and really enjoyed them. Like all JRDG work they are gems to behold and are built to exceptional standards. I just retired the little 525's, they were used  in bridged mode as low frequency amps for a large system. Very  musical, lovely w/ piano tones and they make prodigious low frequencies, especially in the 900w/ bridged mode. What I appreciate about them is the solid billet aluminum casework which is as beautiful as it is functional. I agree that the 535 best the 525 a bit but the entire line is impressive. FYI I now have twin Rowland 625 S2 amps  for horizontal bi-amping on a large system.
All in all Jeff's are some of the best in the class amps in the D range.

The PS Audio Signature BHK 250 or 300 Mono Blocks. For the Money about $7000 each you cannot touch the performance.
combination of Tubes and solid state.
King knows what he is doing. Service is also fantastic you can pick up the phone and talk to Paul the P in PS audio. Had a question about a Marantz unit took them 3 weeks to respond.

Purchased a used PS Audio DAC was out of wanrenty was trying to do a software update had a bad memory card they spent an hour on the phone trying to help and then sent me an updated memory card at no charge. Thought if they offer this kind of service then they stand behind what they sell and that has been my experience. Bought a Audioquest Niagara 5000  on the advice of my local dealer was very disappointing. Traded it in on a PS Audio Power Plant 15 what an incredible difference it made to my system.


I also have two Pass Lab amps that the build quality is fantastic.

I see quite a few people here have PS Audio amps and are happy with them. I have heard various PS Audio kit and currently have three of their Power Plants along with a DAC and an older phono stage: I'm delighted by the quality and price. My daughter and I visited them at their previous location in Boulder CO (they moved across the street a few weeks ago), and they are not only dedicated to the craft they are remarkably friendly and accessible. A few years ago I inadvertently damaged one of my PS Audio remotes, I called them and they sent a free replacement. This is a company that values their customers and is committed to quality and value. Musically, I am delighted with the products.

I never considered Class D until some very respected folks on this site recommended I put Lyngdorf in my rotation of amps I was auditioning. To my amazement it sounded better than any of the analog solid state or tube amps it met. This was a consensus across a very diversified group of individuals I use to sample my upgrades in progress. Even LTA with full upgrades didn't compete. Give Lyngdorf a try. It will also save you the cost of a D/A converter too. It was also superior with analog inputs. That was an ever bigger surprise. 

My tube power amp went down due to a bad tube and I decided to purchase a PS Audio Stellar S300 to use until I had time to repair my tube amp. It was inexpensive and had good reviews. I still have not repaired my tube amp and that was months ago. The S300 is very good, especially for the price. 

I had Nuforce Reference 9 V3 but think they lack some "flesh" on music, Bel Canto and a Halcro MC20 were a little bit better but not perfect to my ears. I have now two Lindemann Musicbook 55 bridged and love everything they give from low to highs and for the holographic soundstage.This brand is famous in germany and Europe, if you have an occasion to listen I think you apreciate.
http://www.hifiplus.com/articles/lindemannproac-system/?page=2

Lots of great recommendations on here.  I own Wyred 4 Sound ST-500 mk 2 and enjoy it a lot.  I've had it for 3 years now and can't complain a bit. They have a 30 day audition period so not much risk there if you want to dip your toe into that water.  My dad, who has been an audiophile for about 50 years, has lived with Bel Canto REF500 for about 12 years now and that says a lot to me.  He has the best sounding system I've ever heard, but I am admittedly biased.  

Recently, I've been looking into an all-in-one box system for convenience purposes and discovered a few more intriguing class D options to include: Peachtree (didn't see this mentioned above), Classe Sigma series (saw that one above), Lyngdorf (TDAI has room correction which could be of good benefit).  

Please let us know where you land!

I have two Nord monoblocks driving Maggie 1.7i’s and I love them. Replaced a Bryston 4b2. Running with Sciit, Auralic, and Audible Illusions.

I used to have GamuT M250i mono blocks & now use Wyred 4 Sound SX-1000R mono blocks & they are excellent. 
FWIW I use them with Boenicke W8SE speakers & Octave HP700 pre.

Speak to Mark at Elite Audio...

Don't forget https://www.elac.com/product/dpa-1m-monoblock-digital-power-amplifier/

I listened to these and thought they were very good

And how many have you actually listened to?

I have immunity against monkey plague and Class D amplification.

Gallium nitride (GaN) semiconductors may be desired over silicon carbide (SiC) for power transistor applications because of the greater bandgap of GaN’s 3.4 eV compared to SiC’s of 1.1 ev, but there still exists a fundamental challenge of not being able to grow pure GaN crystals any larger than about 2". This is a limiting factor from a manufacturing standpoint for the general uptake of GaN in power applications; most manufacturers have to use a doped version which is poorer performing and more expensive compared to pure SiC crystals, which can be grown to double and larger sizes. Also, gallium is a rare earth element, silicon, um, not so much.

Thanks again guys!   Some great suggestions.  I’ve got plenty to go at & will be hearing a few over the next few weeks.

I wrote a big long thread cataloging my Class D/T history, but my browser must have refreshed & lost it.    Lesson learned, I’ll cut & paste from a word doc in future.
I’ll rewrite it when I have time.

Hello tweak1,

    You stated:
" noble/Tim

FYI: I had 2 EP 100.2SEs (with upgraded fuses) for well over a year. I got the bug and bought a Audio Alchemy DPA-1 stereo amp. It is much richer in the midrange and bass, deeper and more holographic sound stage= much closer to real music."

     Good to know, I'm always interested in learning about other good class D amps.  Thanks.
     I currently use my EP 100.2SE in bridged mode to power my Magnepan CC3 center channel speaker and my ClassD Audio unit in stereo mode to power my rear surrounds for HT usage.  I have no current complaints but I'm always open to upgrades in performance. Lots of very good class D options now available that I'd like to audition.

Thanx,
  Tim