However, when I installed my Class D Anthem M1 mono blocks, it was hands down no comparison in performance upgrade I heard immediately. The M1's blew away everything, no harshness at all, better sound stage/imaging and monstrous immense power. And no warm up needed, they just plain old sound fabulous. Hey, who could ask for anything more than 2000 watts per channel?
Which Class D Amplifier? PS Audio, Ghent, Nord, Merrill or other???
I’ve seen various brands mentioned, such as PS Audio, Ghent, Nord, Merrel to name a few, but I’ve not heard any of them.
Which company is producing the best sounding Class D?
Which models should I be looking to demo?
Thanks
I had a Parasound Zone Master Class D amp on loan to give an evaluation of. It uses the ICE Power modules and in that particular case, it did sound better after a long warm up period or as Parasound told me at least a 200 hour break in period. And although it did sound better, to me it still had a high frequency range harshness which I didn't like. I removed it from service and put the A51 back in which of course is the Class A/AB amp and it was more pleasing to me. The zone master did have a noticeable boost in low/mid range and it was a 600 watt per channel vs. 400 watt as in the A51 at 4 ohms. However, when I installed my Class D Anthem M1 mono blocks, it was hands down no comparison in performance upgrade I heard immediately. The M1's blew away everything, no harshness at all, better sound stage/imaging and monstrous immense power. And no warm up needed, they just plain old sound fabulous. Hey, who could ask for anything more than 2000 watts per channel? |
I'd like to answer George (above): Amps are adjusted and calibrated at the factory for peak performance after a short 1/2-1hr warm when they've reached operating temperature, even tubes, to say they sound better after hours and hours is a furphy. With another quote of his from another thread:
Best, E |
Eric’s report of very long warm up time for ICEpower amps is similar to mine.... Glad to hear I am not alone. Although with my old ROland M312 I started to hear better sound after one hour or so.... Ahhh! This reminds me of a JR Class D amp I heard years ago, cold. It was painful to listen to. It was only many years later that I went with all Class D and didn’t put the two together. Thanks! E |
Hello slimpikins5, if your amps do not require warm up, go with what your ears tell you.... Eric's report of very long warm up time for ICEpower amps is similar to mine.... Although with my old ROland M312 I started to hear better sound after one hour or so.... Very good sound after 24 hours of power up and crunching some signal, and best performance after one more day or two. NCore 1200 devices seem to have a faster warmup curve. As for George... Perhaps he and I are not talking to the same manufacturers *Grins!* Or perhaps his ears are dramatically different from mine and Eric's. About 24/7 power up.... I confess that my wintertime 24/7 practice will come to a schreeching halt by may, when the thunderstorm season starts around.... At that time I will change to a "turn off after music" policy. ... Even now, if I hear any distance thunder in the middle of the night, I get up, power down, and then disconnect the entire system from the AC outlets. G.
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I can tell you why my amps are Always turned off after each use: Lightning strikes! I turn them off by unplugging from the wall. At $7K its not worth risking damage. I lost my entire sound system/ TV/ Digital readout on my Bridgeport mill, and more due to a strike which came in via the main power supply from the street. This is the second time I have been hit. The first came in from the grounding system and took out my well pump. |
georgehifi stated: " Amps are adjusted and calibrated at the factory for peak performance after a short 1/2-1 hr warm when they've reached operating temperature, even tubes, to say they sound better after hours and hours is a furphy." furphy? Please take our official multiple choice quiz on this weird word's meaning: A. furphy: An Australian English slang word meaning an erroneous or improbable story that is claimed to be true. B. furphy: An Australian English slang word describing the sound a down-under cat makes when attempting to cough up a fur ball. C. furphy: An Australian slang word, only permitted to be utilized in emails but forbidden to be ever spoken aloud and exclusively used by members of a certain Australian political fan club, that members claim translates to American English as 'covfefe'. D. furphy: How an Australian pronounces the word 'thirsty' after downing 2 gallons of Foster's beer. Correct entries may or may not be eligible to win an official Aussie Georgehifi Furry Fluffy Furphy Action Figure that performs Frequent Forward Flips, unofficially but commonly also known down-under as an OAGFFFAFFF just for fun. Batteries not included, Tim |
As far as warm up is concerned, I cannot hear any differences in a cold start up vs. the amp having been on for 4 hours... other than Bourbon has taken over and everything in the room is just better. Me neither. I can only hear it after at least 24 hours. I suspect this is very amp specific however. But mine are stock ICEpower modules. YMMV. |
As far as warm up is concerned, other than Bourbon has taken over and everything in the room is just better. +1 and more!! Amps are adjusted and calibrated at the factory for peak performance after a short 1/2-1hr warm when they've reached operating temperature, even tubes, to say they sound better after hours and hours is a furphy. Yes electrolytic capacitors like to be formed/polarized with a little time from new, this again is only a short time, and not every time it's turned on. Cheers George |
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 |
My experience aligns with Eric's.... All class D amps I have had in my system require warm up.... Particularly older generation class D could sound rather dry at power up time.... To sound their best, 24 hours or more were a must.... More recent amps, such as Rowland M925 and M535 sound pretty good a few minutes after power up, but if you want them to give you their very best, warm up is definitely necessary. Don't want to warm them up? No problem... Do what I do.... Leave them on at idele 24/7.... Being some 95% to 97% efficient, you will never notice their existance on your monthly AC bill, nor will they ever heat up your house..... Just remember to unplug your entire system when thunderstorms are around. G.
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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 :) |
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. |
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 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. 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... |
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. |
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. |
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 |
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. |

