Today I picked up my Atma-Sphere Class D Amps. These aren’t broken in yet. And they are simply amazing. I’ve listen to a lot of High End Class D. Some that cost many times what Atma-Sphere Class D costs. I wasn’t a fan of any of them. But these amps are amazing. I really expected to hate them. So my expectations were low. The Details are of what I’ve never heard from any other amps. They are extremely neutral. To say the realism is is extremely good is a gross understatement. They are so transparent it’s scary. These amps just grab you and suck you into the music. After I live with them some and get them broken in. And do some comparisons to some other high end Amps Solid State, Tubes and Class D’s, also in other systems I’ll do a more comprehensive review. But for now, these are simply amazing amps.. Congrats to Ralph and his team. You guys nailed on these.
My own extensive experience with my Voyager GaN 350 (said to be the same as the Peachtree) is that is chameleon-like
lol, yeah, with a load dependent frequency response, I would expect quite the ride....
"Class D amplifiers have a low pass filter that can interact with the load if not designed well and that is what we have here. The impact falls clearly in audible band. This would be OK for a budget amplifier in $100 range but not in this class. Depending on what speaker you hook up to this amplifier, the highs may be exaggerated or filtered."
Just heard back from the guy that had brought it over last month. Yes it was the GaN 400….. One I heard last year was the Nova 500. Neither were as good as the Atma-Sphere Class D. Will for the fun of it put them side by side in both systems.
No one said the Peachtree was Better than the ATMA......But the $3500 bundle with the Gan 400 and the Pre/DAC by Peachtree is one heck of a value for us folks that can't afford the ATMA....the ease of play and subtle details that come out of the music is eye opening....I'm hearing info on songs I've been playing for years with my Tube amps that I didn't hear before. Very detailed and very musical.....For the money...it's supurb. Maybe someday I'll get the ATMA....but for now, I'm a very happy camper....gotta' go listen to MUSIC.
Hmm, Class D amps. In the old days, I was just a Class A amp sort of guy; I went from an Pass Aleph 5, to an Aleph 2, then to the Aleph 1.2, which are big bruiser amps that when they reach their stride in terms of operating temperature, it can turn my listening room into a sauna - not a good feel, hah! I've been toying with a second system where I enjoy swapping components in and out, and I bought a very nice pair of Audio Research DS450M monoblock amps, which are Class D. For an amp that is not the current Class D design, I like it, as long as it is connected to a good tube preamp. It stays cool to the touch during extended play time, and it is fast and dynamic; at 650 wpc in to 4 ohms, and it has something like 180,000 uF of capacitance in each mono which aids in that fast overall presentation. That ARC amp really gets my Utopia and VSA VR-4 SR Mk IIIs singing good. I like it, but like all things, some will hear and feel different about it. In any case, congrats on the new amps!
I’ve been a 45/46 SET guy for several years now. I’ve been looking for a Class D solution that can approach my experience with the SET amps. I read some of Ralph Karsten's (who I have much respect for) comments re: his Class D monoblocks, I ordered a pair. I waited a little over 3 months to receive them and have now had them in house for about a month. I can’t say they are equal to the 45/46 SETs sonically, but they are the closest that I’ve heard from a solid state amp. Admittedly, I don’t have a lot of reference for that statement, just the best that I have heard.
One additional comment, while waiting for the Atma-Sphere monoblocks to arrive - I purchased an M3a-800S Stereo Class D from a local company D-Sonic. I will say that to my ears, it’s an outstanding amplifier. I haven’t compared it side to side against the Atma-Sphere amps, but it is very close, and at $1500 is a real bargain IMO.
The two amps are playing in different rooms through different systems. I have no idea what the measurements are for these amps, and don’t really care - they both sound really awesome to my old ears and I’m very happy
I’ll call you on your claim that you heard the Atmaspere class d amp and find the Peachtree superior, even dollar for dollar. I dont believe you.
@ghasley+1. I don’t believe for a second that @mbmihas heard the Atmasphere Class D amp and is just pulling this stuff out of his arse because he likes his Peachtree and can’t afford Ralph’s amp. Sad.
Their power cables are marvelous sounding in my audio system.
I am utterly happy with them and IMO a very cost effective purchase. An example of a high quality product/company that flies beneath the radar.
Not listening to a word this mbmi guy is saying. @soixyou nailed it it this class guy has never heard the Atmas-Sphere gear and I will bet he never heard the Voyger either. I suspect his tube gear was weak also.
Trying so hard to ignore this thread and the urge to replace a room heating EL34 integrated that takes 20 minutes to hit its stride and will never come with a remote based on principle with a pair of these and a preamp. What is that last 5-10% that does not quite equal tubes?
I’ve put together a pretty good system. I’ve tried a ton of Class D. I’ve never found one that I liked. Or would be close enough to my MA-1’s for summer listening.
You bought a pair of amps expecting to hate them? Strange approach to putting together a great sounding system. Could you elaborate? Your system, strategy, venue
You bought a pair of amps expecting to hate them? Strange approach to putting together a great sounding system. Could you elaborate? Your system, strategy, venue.
@hilde45This has apparently been answered by others, but customer feedback suggests the break-in time is real and is about 3 days or so. The amp does not seem to have a 'warmup' time though.
1. People would only use the words “better than” when referring to specs
2. When referring to sound the would say “I prefer… and then why
3. Amp designers would state their objective… straight wire with gain….low distortion with 2nd harmonic dominant….low distortion with 3rd harmonic dominant …etc….. I think Ralph has said this describes his amp
4. Audio enthusiasts would admit that the best products all sound so good that on any given day, what you preferred yesterday may not be preferred today
As for Ralph’s class d amps… is the music vivid and engaging? Are the harmonics rich? Do pianos sound right? How about horns? Is there sibilance? Is the soundstage engulfing? How do cymbals sound? How about drum hit?
These are some of the things that will convey to me how the amp sounds and whether I should try it
Yes to all. When the guys came over. We played several pieces that highlights each of the instrument's that you mention and more. As I mentioned before the Realism and True to the Instruments is incredible. The Amps like my MA-1’s just suck you in and transport you to the concert. I found my self at times walking into the room looking for the band. They don’t have the bloom and soundstage the MA-1’s have. But, they still do very good. Soundstage is deep and wide. Cymbals, Drum taps and kicks, Brushes, Piano, Sax, Guitars all are what they should be. And these are NOT dry and lifeless. Nor bright. But they aren’t sleeping either. Simply put for the money. I’d say best I’ve heard under $10,000. Reguardless of SS, Tube, Highbrid, Class D. The XA.8 and .5 Pass guys that came but loved them. As did the Tube Guys. I was going back and forth buying Pass XA 30.8, XA 60.8 or Atma-Sphere Class D. I am very happy with my decision.
As for Ralph’s class d amps… is the music vivid and engaging? Are the harmonics rich? Do pianos sound right? How about horns? Is there sibilance? Is the soundstage engulfing? How do cymbals sound? How about drum hit?
All Bel Canto made from 2012 on.
A few of the current higher end Peachtree.
Purifi, Crown, NAD, Hegal and 7 others I don’t remember which. All were the top tier of their offerings. Most 2020 and newer. 2021 was a big listening year.
Other Amps I’ve owned or had in my system. Most I have owned and sold off. Only Amp I have kept is the Atma-Sphere MA-1. M-60 and S-30 were great. But why keep them when I have an MA-1.
Pass Labs XA30.8. Xa60.8, X 250.5, McIntosh MC 452, MC462, MC275, MC250, MC225, Atma-Sphere MA-1, M-60, S-30, Quicksilver M60, silver 88, Dynaco St-70, Dynaco SCA-35, NAD forgot which one, Van Alstine, Adcom GFA 565, 545 and 535, Onkyo, Marantz, Pioneer, Coincendence Frankenstein, and another Coincidence, Spectral, Accuphase, Luxman, and various ARC Ref Series and not. A few samples of Rogue Audio also. I am sure there is quite a few I have missed. I’ve been fortunate to own or borrow many many Amps. Some of these Ralph rehabbed for me.
In short the Atma-Sphere Class D amps are simply amazing. In my system I prefer my Fully Optioned MA-1’s over all other amps I’ve owned or had in my system. Although I do really like the Pass XA series as well.
Any plans for a higher power mono amps in the future?
Yes.
3. Amp designers would state their objective… straight wire with gain….low distortion with 2nd harmonic dominant….low distortion with 3rd harmonic dominant …etc….. I think Ralph has said this describes his amp
A 'straight wire with gain' is better described by our tube amps since they don't double power as the load impedance is halved, which is in keeping with how a 'straight wire with gain' would behave :)
Our goal was as low distortion as possible. What distortion we get tends to the the 2nd and 3rd.
thanks ralph....I suspect that this is part of the explanation as to why your amps sound so good.
follow up question regarding a higher powered class d amp...would this be of much benefit to people running speakers with 90db+ sensitivity and listening below 85db?
The Watt Wars of the late 70’s and 80’s is still live and well. People maybe shocked if they measured what they use at listening levels. So far in my room on 86-105 db speakers loudness, control, finesse hasn’t been an issue. For these amps. Not saying at times more power could be used. They can drive hard loads well. Nelson Pass talks about the First Watt. And builds amps to stay in Class A to various Watts then switch to Class AB. Why? He knows that almost all the time those amps will hardly leave if ever Class A. But people can say they have a 400 watt amp that mostly runs under 20 watts. Unless run really hard at High SPL with Lows dipping hard. I’ve run the Atma-Sphere hard on Manepans at very high SPL with very complex music. They showed no signs of fatigue or weakness. Next weekend I am going to try them in a larger room driving bigger harder speakers. My room is 30x25.
But hey if people feel the need for Watts…. Watts it is…. JMHO
Honestly, I think Atma-Sphere jumping into a "Class D', GaN amp is one of the most interesting developments in HiFi in a quite a while. I've always admired the Atma-Sphere OTL designs, but ended up wanting a slightly different sound so I went with Joule Electra and had a pair of VZN-160s for years. I also spent a bunch of time listening to David Berning's "OTL" offerings about 20 years ago and actually own a Linear Tube Audio amp now (among others).
A couple of weeks ago, I picked up a Technics g700m2 ($2,699) to play around with and I've honestly a bit stunned by how good it is. I haven't gotten around to "picking winners" (and probably never will) but the Technics competes with the LTA Z40i and McGary/Backert Labs combo that I have in another room (speakers are Fleetwood Deville's and Volti Rivals). They all have different strengths, but it's really hard to find fault with any of them. I tried the same experiment with a NAD M33 last year and got rid of the M33 in a couple of months.
I think there is a really good reason that Ralph went with GaN when he decided to take the class D plunge--I suspect it may actually be a game changing, transformative technology in the audio world. I've played with the Technics (and love it), and also have heard the AGD "Tube" GaN amps quite a few times (which is also great). Looking forward to hearing the Atma-Sphere version at some point, so really interesting to hear the OPs thoughts on his new amps. I wonder how many manufacturers will be pumping out GaN based amps five years from now?
follow up question regarding a higher powered class d amp...would this be of much benefit to people running speakers with 90db+ sensitivity and listening below 85db?
Unless the room is enormous, probably not. In the average room that would work quite well. In most rooms at 85dB and speakers like that the amp would be loafing.
It would be nice to be able to see photos of the interior of the monoblocks, as @ricevs has requested.
If only to make sure there is not a Purifi module in there. :)
There is a video on youtube. Search on my name and it comes up easily. Its questions and answers from an audiophile society in the Bay area of California. I had one of the amps open in my system and showed the interior. There's no Purifi module :)
So, one thing that would make it sound more open sounding is to remove the steel plate over the transformer and removed the steel bolt. Then you raise the transformer off the chassis and place it on a one half inch thick piece of wood.....you can lightly glue the wood to the chassis and also glue (Amazing Goop) the transformer to the wood......just so it does not move around. When shipping the unit then put the steel stuff back in place to make it more secure. By removing the steel and getting the transformer off the chassis the sound will open up mucho. You can try this simply without the glue and it will take just a few minutes to remove both covers and remove the steel hardware and stick a piece of wood underneath......WHO will be first to try this?
The Cardas binding posts are good but even better is to get rid of the posts, put slightly longer wire on the output and clamp that wire directly to your speaker cables using nylon bolts, washers and nuts sitting right outside the binding post holes....If you remove the spade or whatever on your speaker wire and clamp to the wire coming out of the amp.....your jaw will drop on the floor.
Of course, you would want to put a Furutech super IEC inlet on the amp and get rid of the stock inlet. Get a fuse holder from Acme and wire it off the Furutech inlet and get one of those new yeller fuses from Quantum Science......
If these were my amps I would do all these things within a couple of hours of them being here......When you know what makes better sound.....well, you have to do it!
Of course, there is more.....always more.....including better feet.....adding mass, etc. etc. etc. into infinity.
How about changing the op amp on the input to a discrete one? Discrete op amps are generally more real and open sounding.
This will be fun, reading the responses.....he he.
@ricevsI wouldn’t be surprised if @atmasphereagrees with some of your suggestions (or some variation thereof), but in retail world they’d also likely up the price by hundreds if not thousands of $$$. Gotta draw the line somewhere to reach a price point the market will bear, and from the impressions of current owners it appears Ralph made very good choices to reach his target price point. Then again, this is why mods in our world are popular and why manufacturers introduce “SE” versions that use higher-quality parts and design techniques.
The one thing I’d ask Ralph is if there’s a stereo version in the future that saves a box, decreases the price, and hopefully preserves most of the magic of the mono blocks (kinda like the AGD Tempo di GaN)? Just hoping 🤞🤞🤞, and congrats on what by all accounts is a ground-breaking new amp!
I believe that @ricevsmeans well with his suggested modifications, but it's easy to be an armchair quarterback and critique the hard efforts of others. Ric have you given thought to bringing an amplifier to market loaded with all of your ideas to compete in this sector?
I too am a class D convert after many years and many amps. It is really hard to say if they are better than class A A/B because of everything has changed along the way, speakers, preamps, DAC’s cables etc. I still love tubes and will probably always have a tube pre with a tube regulated power supply, a professional (recordings studio DAC / Streamer) and class D Amps because of sound, weight and heat. In summary class D with ultra fast switching (GaN) is pretty good. Good enough to pay attention too. I own AGD and don’t plan to change any time soon. They just work and sound great and should not be ignored when looking at amps.
A couple years ago Ric came out with his EVS 1200, based on the same IcePower modules that PS Audio eventually came out with using the same modules in their M1200s 9but at ~ 3Xs the price). Ric made a lot of improvements to the modules, though some issues could not be addressed. I raved about it in a AG thread that had many hundreds of followers, that is until my LSA Voyager 350 GaN amp arrived (about a year later). IMHO, from the first note, there was simply no comparison. Ric mods stock Voyagers, which may be the best audio bang for the buck going
So, one thing that would make it sound more open sounding is to remove the steel plate over the transformer and removed the steel bolt.
I’ll let you in on a secret. Use Non-magnetic stainless bolts and then you don’t have to go thru all that. A regular steel bolt heats up because its a magnetic resistance to the transformer and typically runs hotter than the transformer itself! Change it out to stainless and the transformer draws less power and runs cooler- and may well put out a slightly higher voltage. But FWIW due to the high amount of feedback, the class D has a lot of power supply noise (and voltage sag) rejection. Class D amps running less feedback will benefit more on this account.
The Cardas binding posts are good but even better is to get rid of the posts, put slightly longer wire on the output and clamp that wire directly to your speaker cables using nylon bolts, washers and nuts sitting right outside the binding post holes
Anyone doing this is really asking for trouble! To start with any manufacturer would void the warranty in a heartbeat. It also doesn’t go down well unless you live in a mancave wearing cargo shorts and no hope of a date :) ... if you get my drift
Of course, you would want to put a Furutech super IEC inlet on the amp and get rid of the stock inlet. Get a fuse holder from Acme and wire it off the Furutech inlet and get one of those new yeller fuses from Quantum Science......
This is a really Bad Idea. In our case there’s an AC filter on the backside of the IEC connector (the amp in the video is from the first production prototype run). If this isn’t present, there could be noise issues. In our amp, the rectifiers in the power supply are the main source of noise and we did a lot to snub them, but the noise filter was added to really make it silent. In this way it puts out less noise on the AC line than most tube amps. You could change out the fuse but I think you’ll find that due to the large amount of feedback, the minuscule voltage drop across the fuse will have no effect whatsoever.
How about changing the op amp on the input to a discrete one? Discrete op amps are generally more real and open sounding.
Here’s another thing I’ll let you in on. What is important in opamps is something called Gain Bandwidth Product. If you have enough to support the feedback in the circuit, there will be no ’sound’ of the opamps other than noise (and in our case the noise floor of the amp is mostly from the opamps). Back in the 1960s and well into the 1980s opamps did have a ’sound’ which is why if you have to change out an opamp in a vintage guitar effects pedal, its important to find an exact replacement or the pedal won’t sound right (guitar players are quite picky about that sort of thing!). Our input buffer has a gain of 2, which is to say there’s a lot of feedback and with modern opamps, as long as you don’t ask more than about 20dB or so, they will be as neutral as you can get.
A friend of mine designed one of the higher performance discreet opamps out there (back when it was still worth it) and he’ll be one of the first to tell you what I did above. IOW doing something like this will result in no benefit whatsoever. To design a class D amp you can’t just wing it by plopping parts in; you have to do the math and understand the engineering behind it.
To design a class D amp you can’t just wing it by plopping parts in; you have to do the math and understand the engineering behind it.
An embarrassment that this even needs mentioning. A sad fact there is always someone out there looking to make money off of the ignorance and insecurity of others.
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