What going fully Class D has taught me.

BAT VK-33SE.

This week I am expecting a Backert tube preamp to go with an ArgentPur amp.  The bypass on the Backert is nice because the unit does not need to be powered on for HT use which will extend tube life.  I was also looking at the new Audio Research LS2 or the Modwright LS99. 

Erik, accuracy means smooth, clarity, period.  That is the real thing. Luxman SS or most other tubes sound buttery because they roll off HF.  They subtract information.  That is not desirable for musicians like me who want to hear as much musical content at all frequencies as possible.

@Viber6 - While I can understand your complaints about tube systems rolling off HF, that's not supported by the measurements of Luxman SS.  

I kind of did the same thing, but with a Yamaha integrated.  My DAC is a Bel Canto e1x fed into the A-S2200, then the Class D bug hit and I was about to buy the e1x amp, but decided to try one of the Hypex Nilai DIY kits the Stereo 500. 

The Nilai has fantastic bass and absolutely no distortion,  I let it run for a week and hoped the highs and the mids would get better.  After a week I popped the Yamaha back in and the glorious mids and highs were back,  The Nilai seemed dark compared to the integrated.  The Nilai seemed to roll off the HF and for a guy that can't hear over 12kHz that surprised me.

I own four Class D systems. I live in the desert so waste heat from audio equipment adds to my HVAC bill. Digital based amps are also vastly more space efficient. The technology is mature. Plus there is nexus between DC amp draw and bass that digital meets easily. I am sensitive to smells also so hot Class AB circuit boards would prevent me from sniffing my wine.  

So it sounds like what you've accomplished is great for movies but only so-so for actual music? That would be a non-starter for me since I don't even have a TV of any kind in my listening room.

Class d is comming of age.marantz, audio research,emotiva,mcintosh,rowland  are all making it and many more. The gan has made them much better. They measure very well.there are some high end classical d amps that are impressive.keep an open mind.enjoy the music

You seem like a good guy @mark200mph , but every time I read your posts I think I'm having a seizure........

I have never heard the Atma-sphere OTL preamp but did hear the Allnic OTL preamp at my home and that was so amazing and surprising. Being a tube preamp, I never expected it to have such detail along with the beautiful holographic tube sound.

My current and past gear has tended to be on the ultra-detail level. I never expected a tube preamp (and the Allnic DAC too) to be the most detailed gear I ever heard (but unfortunately not own).

I currently have a Benchmark HPA4 preamp, and I think the Allnic sounded more detailed. Definitely sounded nicer overall.

Must be my old ears, but my 58 lb Spectron musical MK lll class D amp designed by John Ulrich, it's output is 500watts@8ohm 650@4ohms and 1,200 watts@1ohm  sounds pretty fine to me, and brings my Maggie's to their knees I think my 30 year old ARC LS15 tube pre amp helps that i have mated to the Spectron I just love that unadulterated power 

I think the comments that generalize about tube amps and HF rolloff (and "too buttery", etc.) is a criticism that some amps and preamps have earned. But that is simply not the case with higher-end tube components in today's world. The clarity, linearity, and tone are all there in spades when the tube amplification is well-designed and quality components have been rigorously integrated. There is a warmth, breathtaking clarity, and intimacy that hits gold when it all comes together.  Apparently, some SS systems do a very nice job as well.  I had years of enjoyment in a tubeless system.  Then I switched and will never go back. You may have to pay more to get where you want to go, in any system chosen. Good luck in your hunt!

• I upgraded from an Audiomat Prelude MKII integrated tube amp to a Luxman MQ-88uC tube amp and a CL-38uC tube preamp which make for magical sound with my QUAD ESL-63 US Monitor electrostatic loudspeakers.  The Quads are made to be paired with tubes and I do agree with the result.  The Atmos-Sphere Class D integrated was briefly tempting but I chose tubes instead.  

@echolane 

Many years ago I tried a Luxman tube amplifier with my Quad ESL-63s - not the US spec ones.

When the Luxman switched on, it sent a transient which the Quads objected to, effectively causing their protection circuits to short the amplifier.  So I never got both to work together in harmony - or at all!

OP

have you heard of GAN amps?? what I meant was audition one? I heard of the AGD which i think sounds liquid enough for one's taste if you like a class a type of amp. I suggest you do hear one. now if that does not fall under your synergy then maybe you should try a vacuum tube amp for mid-highs. and obviously a tube-based preamp

just my 02 cents

I have class d amps in my subs. seem to fit that purpose. I have two tube monoblocks and a tube pre-amp, sounds great. I only listen to music on this rig. I have a separate system for TV. (not really into the home theater thing, my leftover equipment does the job)

I think the comments that generalize about tube amps and HF rolloff (and "too buttery", etc.) is a criticism that some amps and preamps have earned. But that is simply not the case with higher-end tube components in today’s world.

What am I missing?  The liquid smooth midrange, buttery treble of the Luxman, which was the main reason I went from Class-D to it in the first place. 

@erik_squires The differences we hear between amps is the distortion signature of the amp. You’d think vanishingly low distortion would have got rid of that issue, but since our ears are highly attuned to higher ordered harmonics that vanishingly low distortion really isn’t as low as it needs to be. Just like they do with musical instruments, our ears assign tonality to harmonics and so higher orders add brightness and harshness.

Many tube amps don’t have the higher orders as audible since they are masked by lower orders. That is why the sound smooth and not as much high frequency energy; its nothing to do with bandwidth, which tube amps have had for many decades. The HK Citation 2 easily makes 50KHz so its not a bandwidth thing. That is why I included the first quote above.

Once you understand that its distortion that causes amps to sound different then as a designer you have an access to getting the amp to sound musical and correct. It helps to know how to apply that understanding to the technology. 

The bottom line is there are class D amps out there that are nice and smooth and don’t take a back seat to the Luxman. You just have to seek them out. 

@ozzy62 Whew....I thought I was the only one.

Started with the Audio Research SP-4/D-100A preamp/amp and the Maggie Tympani 1-D 48 years ago.

I’ve had the Class D Lyngdorf TDAI-3400 for 5 years. Just got the new Magnepan 2.7x to replace my 1.7i. Absolutely breathtaking in a 22’x 40’x 14’ (ceiling height) room. Streaming direct from Qobuz app on iPhone to the Lyngdorf via Qobuz Connect, bypassing my Aurender. 
 

Lyngdorf is light, cool (I’m in Hawaii), 400W per channel into 4ohms, software updates wirelessly, and delivers clean sound. Works flawlessly. 
 

Hope this helps. 

What? Abandoned this thread?  Due to physical injury and being caught up in research I've not been paying attention.  What a needy bunch!!   Like you all need me to participate to begin with.  

OK, here you go, first two publicly available pics are in my blog.  

No, never got to hear GaN.  Honestly it was so over hyped I got turned off, but also, I live in the boonies and with modest ability to really get to an interesting store.  

The tweeters on the top of the SNR-1 are the only good investment I've made besides gold.  They are worth twice what I paid for them six years ago.  

@erik_squires 

"Powering"

Better fix it before Roxy sees it..!

@srinisr - Thanks, already fixed. 

I went all Class D in my car system, ARC Audio Blackbird and Nighthawk, even with the speaker, all activ with no passive components and was blown away at how far Class D has come.  It definitely has come of age.  I just wish ARC Audio made comparable home equipment.

Class D can be good, but good ones are still the rare exception IME. Most of them remain rather sterile, cold and grainy. 

@erik_squires --

Focusing on the difference in amp to speaker interfacing through the passive/active configuration and the effect it has/what it facilitates sound-wise (which also, to some extend, comes down to the Hypex DSP section in the active scenario) it’s important to have in mind that, presumably, you’ve only heard either amp - the Luxman and the Hypex solution - in each their particular configuration, passive in one and active in the other, and this is not trivial - certainly insofar what you’re pursuing here is a more isolated assessment on the different amp designs/topologies, or active vs. passive more fundamentally for that matter.  

An active setup isn’t confined to plate amps of a certain design nor a DSP that’s tied to it; try imagining using 2 of your Luxman stereo amps to run your 2-way speakers actively with a 2 ch. input/6 ch. output external DSP, and then setting up your sub towers actively with Hypex plate amps and using the same external DSP. Yes, it would be more expensive with the need for yet a Luxman amp + an external DSP, but for the sake of the experiment ignore that for a moment and consider the following: you would "get to know" your Luxman amps in a different context, one that would free them up and which, I’d argue, could make you have your cake and eat it too.  

As it is though you’ve placed yourself in a bit of a quandary: a particular active scenario has you yearning for certain traits of the passive one, and vice versa. Coming down to it class D technology more broadly has something to offer that would border on the Luxman, and conversely the Luxman is only one tasting of class A/B. Not to mention what the interference of a passive crossover between a given amp and speakers, or its negation, does to the sound - both of that generated by the amp and that coming from the speakers.

Bridging the divide here and getting more or less the best of both worlds is certainly possible. To me active is the only route, and once you make that decision and refuse to let yourself be limited by a particular amp design, a bundled solution or other, there’s really no reason why you won’t find yourself outside of named quandary - not least in light of your entrepreneurial spirit and technical insights. 

Maybe I’m just lucky, but the 2 class D amps I bought to use in my space constrained home office both sound very good on a succession of speakers (good 2-ways including Harbeth 30.1s, ATC SCM12 Pro, and KEF 103.2):

• Wyred 4 Sound ST-500 (ICEPower): sounds great at all volumes, not sterile, cold or edgy in the least. It puts out so little heat that (w/W4S’s approval) I stand it on its side IMS)
• bel canto 600M mono amps (NCore): also sound great all volumes, also not sterile, cold or edgy. The sound is a bit more resolved and elevated than the W4S, but these are very small differences

I no longer have big speakers in big rooms. My office system is a pretty high level nearfield setup. So I can’t claim that either of these class D amps would equal tube amps or good A/B amps in terms of soundstaging and timbral accuracy in typical (not nearfield) system setups. But IMS and for my needs, both amps are ideal.

FWIW, I am now and always have been very sensitive to edgy, tense-sounding SS components (have owned a number of amps/preamps/DACs like that). These class Ds are not in that camp at all. 

For very revealing two channel, D still leaves something to be desired. It's definitely the only way to go for home theater and multi channel. BTW, ICE has fallen way behind. For the best bang for buck look to Purifi Eigentakt or Hypex NCX500 modules. 

I don't know about ICE falling behind, but to my ears it has a warmer sound.  Closer to Parasound Halo amps than my Luxman for instance.  I don't need it to be better IMHO, it's just got its own signature, much like linear amps. 

@phusis  - I specifically made the sacrifice to minimize the cables I'd need otherwise, especially when trying to integrate HT and 2-channel sound.  Last thing I need is multiple amps, external DSP and more cables. 

I've realized recently my Hypex plate amps have 2 RCA inputs.  This makes it possible to run a separate source chain (DAC/preamp) directly without the usual HT bypass features. 

After going through so many threads, one things is for sure - Class D's performance surely is confusing.

Sometimes, I think that is because people are so much used to Class AB that a small amplifiers running huge speakers affects them psychologically? But again there are a few threads where I have read some folks who were into SET amplification have found GaN amplification similar to SET amps and have switched to class D.

The only way to find out is by personally experiencing Class D. I was seriously thinking of NAD M23 v2, AGD Duet, any other Purifi based amps, etc.

The only way to find out is by personally experiencing Class D. I was seriously thinking of NAD M23 v2, AGD Duet, any other Purifi based amps, etc.

Exactly right. If a bear sings Puccini in the woods the only way to know if he's talented is to go listen for yourself. 

@milpai  - I really do think it's half old myths die hard but also, half is I've become accustomed to this tweaky, unique sounding 12 Watt Class A amp and the Class D amp I listened to for 30 seconds doesn't sound like it. 

Fine, fine, I’ll chime in. Over many years of experimenting in my own system, I have concluded that it’s the preamp that is the heart of your system’s electrical performance fingerprint. The amp simply makes the preamp’s sonic signature louder. For me, as I prefer the lush, rich, harmonic subtleties of tubes (yes, we can debate if that is “distortion” and if that is good or bad, etc.), I have found that employing the best tube preamp for your tastes/budget, and then amplifying that signal with whatever amp works best for your speaker’s unique electrical characteristics, is the best approach.

I’m not an electrical engineer, but I’ve come to believe, through lots of system configurations over the years, that the power amp is simply an extension of the electrical circuitry of your speakers. You might think of the amp as part of your speaker (I know I’m gonna catch flak for that, but that has been my experience). From that context, the amp simply does what the preamp tells it to, in order to “mate” with your speaker’s electrical characteristics. Things like impedance, sensitivity, etc of your speakers can help define the best amp for them, rather than focusing on the amp’s “sonic personality” per se.

I have had good results with modern class D amps to drive full-range speakers, with tube preamps up front. Certainly, for subwoofers, class D has clear advantages.

The good news? We have Audiogon to feed this addiction. It could be worse – we could be obsessed with vintage cars.  ;-)

I think you are right and it is even at low cost in my system my own experience too ...

Fine, fine, I’ll chime in. Over many years of experimenting in my own system, I have concluded that it’s the preamp that is the heart of your system’s electrical performance fingerprint. The amp simply makes the preamp’s sonic signature louder. For me, as I prefer the lush, rich, harmonic subtleties of tubes (yes, we can debate if that is “distortion” and if that is good or bad, etc.), I have found that employing the best tube preamp for your tastes/budget, and then amplifying that signal with whatever amp works best for your speaker’s unique electrical characteristics, is the best approach.

I’m not an electrical engineer, but I’ve come to believe, through lots of system configurations over the years, that the power amp is simply an extension of the electrical circuitry of your speakers. You might think of the amp as part of your speaker (I know I’m gonna catch flak for that, but that has been my experience). From that context, the amp simply does what the preamp tells it to, in order to “mate” with your speaker’s electrical characteristics. Things like impedance, sensitivity, etc of your speakers can help define the best amp for them, rather than focusing on the amp’s “sonic personality” per se.

I have had good results with modern class D amps to drive full-range speakers, with tube preamps up front. Certainly, for subwoofers, class D has clear advantages.

The good news? We have Audiogon to feed this addiction. It could be worse – we could be obsessed with vintage cars.  ;-)

@mhwalker  - I think you are right.  When I have funding sources again I plan to get a 2 channel tube preamp to fully restore my musical experience. 

Just another confused thread... He confused the sonic gains from the active crossover (vs passive) and attributed it to the use of class D. Once he ditches the class D with class A/AB, while retaining the active crossover...he shall realize class D was nothing but a diddly.

Forget the luxman, when he tries even a cheap schiit gjallarhorn (class A ish continuity topology) on low power drivers and a cheap schiit vidar for the woofers while retaining the active crossover, he shall realize how crappy his class D really was.

@erik_squires --

Focusing on the difference in amp to speaker interfacing through the passive/active configuration and the effect it has/what it facilitates sound-wise (which also, to some extend, comes down to the Hypex DSP section in the active scenario) it’s important to have in mind that, presumably, you’ve only heard either amp - the Luxman and the Hypex solution - in each their particular configuration, passive in one and active in the other, and this is not trivial - certainly insofar what you’re pursuing here is a more isolated assessment on the different amp designs/topologies, or active vs. passive more fundamentally for that matter. 

If you are a really bad dancer with no sense of timing and rhythm Class D will probably be OK.For those that do get that stuff and enjoy rhythmically interesting and engaging music it is poor choice.The class D amps I have tried completely mangled those aspects of the sound.Purifi slightly less bad than Hypex but still terrible. For example swing music has no swing.More musicality deletion units than amplifiers.