Class D = Trash?


So, I'm on my second class D amp. The first one, a Teac AI-301DA which claimed to use an ICE module, was unlistenable trash. I burned it in for a few weeks, it just couldn't perform, so I sent it back. Following that, I tried the new Emotiva A-300 (class A/B). It was significantly better, but lacking in too many ways for my tastes. So I changed gears, got an 845 SET from China -- and it was an immediate and massive improvement.

So, before I went further down the SET road, I wanted to try a better class D product using a modern class D module. I settled on the D-Sonic M3-800S with the Pascal module and custom input stage. I read from reviews that these things like to have big cables, so I picked up an eBay 8 gauge power cable (Maze Audio, el-cheapo Oyaide copy plugs, braided 4-wire cable) to go along with it.

Mid-range GONE.
Soundstage depth CRUSHED.
Euphonics DISAPPEARED.

Yes, resolution went up. Driver control went up, allowing me to play compressed rock/pop and orchestra with the speakers being able to render it all. But enjoyment in the sound is basically gone. Using my best power cable (LessLoss Original) improved performance, but didn't fundamentally change the amp's nature. I ran back to my headphones (Focal Utopias) to detox my ear canals.

So, how long does a class D need to burn-in? I want to give it a fair shake before writing the technology off forever. 
madavid0
I'm with you  madavid0 .

The only one I've heard that did something for me was the Bel Canto 600 monoblocks, but that was only with an expensive two way with a Raven tweeter that had a very flat, benign impedance curve of 4ohms.

I didn't like it on a different speaker that had an impedance curve that had up and down impedance's like most speakers have. I could see it being good with Maggie's as they are also a benign 4ohm load.

Cheers George    
PS Audio has one coming in May that uses a Class A MOSFET input stage and then a Class D output stage for the power.

I think there are others like that

The nad Masters series should be pretty good and IIRC it is Class D

I would not give up on an entire circuit topology based on two examples, but I would be very careful and not purchase without a listening test or a return privilege.
The Spectron Musician III Mk.2 and Merrill Veritas are definitely not trash.  Both sounded as good as my Sanders Magtech.
Subjective preferences at play here. No more, no less. I owned several 845 amps and liked them. I like my Class D Lyngdorf even bettter however. All about the total system  anyway and it's synergy or lack of it according your your ears alone. 
Class D has a way to go before it can compare favorably with a good class A or A/B amp. I dumped Class D monoblocks with Class A inputs because they still didn't come close. In my opinion.
I dumped several Cass A and A/B amps because they weren't to my liking. I guess they, as a whole group of amps,  are not ready for primetime 😁 I also did not like a couple of tube amps in my audio life. I guess tube amps are ready for the trash. 

Yes this comment is silly, but exactly what I read often times about Class D in posts. Many, many varieties of Class D amps to pick from. Seems a little overreaching to say they are all not yet ready for primetime.  
I had a Rotel RB-1092 that served me well with Dynaudio Audience 52SE speakers.  I enjoyed that paring quite well.
if your speakers represent a very complex impedance, then maybe it is cables - it is certainly cheaper to try different ones from a place that lets you swap them
I have 3 set of speakers. Chane 1.4s, garbage. Zu Omen Mk.II -- good dyanmics, okay-ish resolution, forward but shallow soundstage. My current reference is the Fritz Carbon 7 SE: http://www.fritzspeakers.com/DreamWeaverFritzCarbon7SESpecPage.asp

These speakers have a very benign impedance and phase curve; I got them specifically to be a good match with the 845. I don't know if there are speakers that are easier to drive. Resolution is improved, I'd call it mid-fi if compared to my headphone rig. On the 845 (the cheapest 845 SET I could find from China) soundstage is extends a few feet beyond the edge of the Carbon, and has a satisfying amount of depth.

But here's the thing: I don't WANT to be tied to some giant space-heater monstrosity that -- if I upgrade to a "real" 845 -- is going to weight 80-120 lbs. Good 845 implementations need elephantine transformers. 1000 volts, JESUS. I want to move forward and live in the present. But not at the expense of the sound.
I don't think you have found the right match-up yet. I made the change from Dynaudio to Tannoy some years back, and so far, the best amp combination is an SET 300B, and a kit-built 500 Wpc Class D Audio. There are two CDA 254 modules that are bridged to mono, and they share the chassis and power supply. This combination really works for me.

Although there is a great disparity in these two types of amps, I get great enjoyment, with no listener fatigue with either amp, driving my Tannoys (vintage 12" HPD, ca 1975, that have been thoroughly updated).

Class D Audio sells assembled amps, or will assemble your choice of amps for a nominal fee. It's a very low-cost option to try to find a suitable match for your system.

Hope you find what you're looking for.

Dan
Madavid0 - I wasn't familiar with your speakers but went ahead and read through as many reviews that I could find about them.  It seems that the consensus is that these speakers really only sound their best with tube amplification (of quality) and one reviewer even started with class D and was disappointed until hooking up a master amp (which I know that you're trying to avoid).

Perhaps you will need to go on the hunt for another set of speakers that mate well with the type of amplification you're comfortable pursuing based on size and budget.

BTW - I don't think that a mismatch between speakers and amplifier is  reason to dismiss the entire class D topology as trash.

As Dan says above - hope to find what you're looking for.

Greg
Of course, those making blanket statements here about Class D have heard ALL the various iterations and embodiments of this amplification approach.  Of course they have.  
All this trash talk about Class D being trash is just that, trash.  I've had my D-Sonic amp now going on 2 years plus, and believe it or not, it's still opening up, improving in every way every time I hear it.  We all have different experiences or perceptions with components.  What got me hooked to this amp was the first time I had ever heard the sound of a drumstick hitting the skin of a snare, and not just  a drum being hit.    My satisfaction grows more every I listen.  I decided to give Class D a chance, and for me, it works very well.   It's been said here a million times: trust your ears.
Wow, this is a switch. The usual Class D thread typically sounds the death knell for class A/B while claiming that class D will save the world. I feel strange...and to respond to the above(shame on you all for leaving Greg hanging!), I still haven’t found, what I’m looking for.
Shtinkydog how long did you have the burn it in?
madavid: I think it's still burning in.  It just keeps on getting better. It's been at least two years since I bought it.

If most class D amps use either the Ice or N Core Modules,  can't one assume that amps made with either of those modules will pretty much sound the same?  I know that various designers monkey around with the input stage and power supply, but an N Core sounds like an N Core and the Ice sounds like the Ice.

I have listened to roughly 6 or 7 Class D amps including the NAD Masters series, The Wyred4Sound amps, the Channel D,  and others I can't really remember the names of and none of them even came close to the Odyssey Stratos Extreme which is in my system.  The 2 words that come to mind is listener fatigue.  Not in my system, ever.

D = duck.
Watch blanket statements. I have listened to about a half dozen Class D using the two most common modules and they ranged from poor to not half bad, but not something for the long haul. I settled on Nuforce/Nuprime which uses a very different style (proprietary to them) of module and their newer designs are highly satisfying, for example the Nuforce Reference 20 monoblocks. My impression is that other companies also have made significant progress in the last year with Class D
I've had my Rogue Sphinx class D (hybrid integrated) for 1.5 years and am quite pleased with it.  In the past I've owned McIntosh, Dynaco, NAD. Not trash, IMO.
Always somebody looking to stir the pot..........

madavid0, you can expect at least 600 hours to 1200 hours of break-in before a class D amp reaches peak performance.


Basically, owning a class D amp requires a modicum of patience... These are not instant gratifiers.


Like with any other classes of amps, some class D amps are extremely good, and other ones, hummmm.... Should best be marketed through Home Depot for chasing squirrels and other varmints from attics.


But no, I am not faintly implying that D-Sonic amps are poor... On the contrary. Most of them are based on Pascal power conversion modules, which are extremely good. Amps based on Pascal M-Pro2 and X-Pro2 or X-Pro1 are likely very good performers, if one is patient enough to break them in.


Lastly, feeding any amp with an arbitrary PC whose only claim to fame is its heavy gage may not be the most effective strategy for getting best results from such device, no metter its class of operation.


Saluti, Guido

 

Mad David

Before I respond to your question: what source material do you have?

Do you listen to the crap that is CD?
Have you at least partially upgraded to SACD?
I doubt you know what DSD downloads refer to.

There is no hope in hell you've listened to vinyl in a long time, if ever.

You are the reason many of us have given up on this forum/website, idiots, all of you!!!!
i'm a SET fan and own a 300b based integrated that's wonderful but hay its 8wch so not all need apply. but i have heard the Jeff Rowland class D stuff and frankly its quite nice ok expensive granted but class D can sound great if done right and the tech is coming along so hold out, i'm sure the tech will mature some and get fantastic. Until then i'll stick with my SET or a good class A ss but i'm open to new ideas  
I commend OP for the headline. It doesn't definitely say D amps are trash; it asks the question does D=trash. And then the body details his negative D amp experiences and poses the basic question: How long will burn in take before his D amp sounds better with his speakers. Guidocorona finally seeks to directly answer this question almost 16 hours after it is first posted. In between that time there's some informative posts that include the possibility/probability that it might not ever happen with his speakers. It's one of the reasons I continue to read the forums.
Peace
Astewart - I will always read these threads because I'll always learn something.

In this case I learned that in one person's opinion:

  • Chane 1.4s, garbage 
  • Zu Omen Mk.II -- good dyanmics, okay-ish resolution, forward but shallow soundstage. 
  • Fritz Carbon 7 - Need to be run with tubes (based on reviews I researched)

And that if you're on a tight budget to get a good amplifier match to run Fritz bookshelf speakers in a pinch that Chinese copies available on eBay aren't that bad.

Actually - Here's what I learned:

Everyone has their own personal taste and idea of what "perfect" or "horrible" sound is.  Have also observed that these biases probably come from some other source, reason or event unrelated to the product itself (room, hearing, what you grew up liking, budget, etc.).

Good thing, is that there's something for everyone and all the fun is in pursuing your perfect sound and system within your ever-changing budget.

Happy to have a forum where we can openly discuss our own preferences and experiences with the very infrequent d*ck ruining everyone else's good time and enjoyment of their music and systems (literally I can count them on one hand).  

The vast majority of people here are true enthusiasts and very gracious.

As for burn-in...  Yes, burn in is a factor but if you don't like the sound (at least a little) "out of the box", it's doubtful you ever will even if the sound is correct and perfect for someone else.

Greg

Gregkohanmim, thanks for the 'go' at attitude correction...;)

D tech is still in relative infancy as the classes go.  Some are already embracing it, others repelled by it.  'Bout on par with all the other classes, given the rather small 'survey group IMHO.  We could discuss/argue the subject ad infinitum and end up back at the start yet again...

Re 'break in', that might be true for any 'solid state' amp, although I've never seen any comment about existing 'non-D' amps.  And when break-in is claimed to take 1K+ hours, I find self wondering which is being 'broken in', the amp or the listener?

Just MHO...  New stuff always seems to bother purists in some way...always has before....;)
I will say this: the first day of the D-Sonic was absolutely horrid, the mids were so rolled off that the ends of words were missing altogether. I figured that was just first-day garbage, and thankfully that's all that it was.

My 845 only took a few hundred hours to burn in. 1200 hours, jesus...I also read someone say that class D can get worse before it gets better during burn-in. D-Sonic offers a 30 day trial period, I guess that's a good 700+ hours. SIGH!

I'm not married to the Fritz speakers, either. I still have the Zu Omens. I do like their forcefull dynamics, and if the D-Sonic can give them depth to their soundstage...eventually...that might be the way I go.


"The kids were so rolled off that the ends of words were missing altogether"

That is one of the strangest things I have ever read on here.
Post removed 
Sorry for the misspellings I meant mids

Having had the chance to hear ICEPower amps the same day as a complete Pass system I have to say I can't concur with the OP, and that the writing style, and omission of specific details has me honestly scratching my head about his / her intentions.

Buy what you like, but the best Class D is very very good. I am a fan of the latest generation B&O amps for many reasons including affordability, size, environmental friendliness.

I do wish I could afford the space for CJ Premiere 8's, which I would probably consider the ICEPower's better for fun and interest, but I cannot, and am quite happy with the compromise.

Best,


E
I can definitely detect that element of...whatever it is. Dryness? Poor blending of upper- mids into highs? Lack of weight? There's a SOMETHING to the sound that hints to listener fatigue.

I fully expect your D-Sonic to sound pretty ragged right now. And you should be prepared to its performance to fluctuate quite a bit for the first few hundred hours... Yes, this means that on occasion it might even sound worse than it does now.... But gradually it will trend for the better, and fluctuations will taper off.


If you have an old FM tuner, feed your amp FM interstation hash whenever you are not using... Even at night that is... THis will accelleate break in.


G.


"islandmandan" - yes... the "Class D Audio" brand of class D amps are great amps at a great price.  As I understand it... they use a linear power supply, rather than a switching power supply, which makes a difference.  I have the SDS 470C, which seems to sound as good as most of my other class A and Class A/B tube and SS amps.  And... of course... it's much smaller and lighter, and easy to move... and... doesn't heat up the room.

I took a chance on it, because the reviews were so good, and it cost so little ($700)... and... it was a good bet.  For that price - everyone should try one - almost nothing to lose!  I'd bet, they would all be surprised... and... pleased.

In case you want to try one:  http://www.classdaudio.com/sds-series-amplifiers/
Also....am I crazy or is this amp casting an unstable image? Like sounds don't want to focus and stay there.

Like....the vocalist says a word that happens a little to the right, but the trailing consonant finishes a little on the left.
In my quest for continuing minimalism, I bought a PS Audio Sprout.  I love it.  It drives my Spatial Audio M1 Turbos effortlessly, with plenty of good noise in a large room.  The inboard DAC is way good enough for my Theta Pearl, I stream Bluetooth from my computer, and hooked up an MP3 player for background music and NPR.  All is well.

My 20-year-old Krell KAV-250 integrated sits unused.  Head to head, l'il Sproutie just sounded more...fun!

It's all that this old fart requires for enjoyment.

Now, maybe, an upgrade to M4 Turbos.  I like the white.

madavid0, what your amp does now is most likely a break-in artifact... Discount it for the next two weeks or so.


If the behavior persists towards the end of the 3rd week, try switching the left/right inputs of the amp around. If the problem changes channel, there is something amiss in the electronic or wire chain.

G.


Those imaging effects are what happens when you have a mismatched speaker pair. Either drivers or crossover components did not match.

Best,

E
Damn, 24 hours later and this amp sounds like trash -- rolled off / recessed mids again, soundstage depth almost gone...wow. I guess this thing with wired class D burn-in is true.

Hello madavid0, please let me be the first to extend to you a warm welcome to the wonderful world of class D breakin Purgatory!


For the next few weeks you shall be our guest... Though shall be regaled by the experience of gnashing of teeth, extreme audiophrenic anxieties, buyer's remorse, snarky comments from wife and friends, plunging self-worth, desperation, upset stomach, gastritis, duodenal ulcerations, persistent tremors, and occasional night terrors.


Please do not despair... Know that there is light at the end of this grizly tunnel.... Sorry, we know you can't see it yet... 'Tis around an untold series of nasty bends, dips, collapsing sound stages, intermodulative shrieks, tubby corners, and halls filled with revolting audio mud.


Please find in the left pocket of your seat a 500 count jar of 250 mg generic Valium fast-acting jell caps, a miner's helmet, and a silicon audiophile-approved teeth guard... Please use the teeth guard during rest periods to prevent teeth from shattering from the inevitable gnashing. Always wear the helmet to prevent head injury when hitting the roof during inevitable fits of audiophrenic rage.... And use Valium as needed to reduce anxiety to a bearable level.


Please enjoy your ride!!!


Signed:


Your devoted Class D Break-in Purgatory Administrator (CDBPA)

   


@guidocorona that was beautiful!
I can definitely detect that element of...whatever it is. Dryness? Poor blending of upper- mids into highs? Lack of weight? There's a SOMETHING to the sound that hints to listener fatigue.
I experienced the same with Ice Power amps. Dry, cold, clinical...lacking depth and instruments not decaying properly. I purchased the amp used so it wasn't a break in issue...I started a thread about it and it appears that the switching frequencies aren't currently high enough to avoid degrading the signal. If it was a simple break in issue, they would be broken in at the factory. 

Don't give up on Class D though. When the switching frequencies improve, they will become the solid state amps of choice. Some folks don't hear what we hear and they are fortunate to enjoy these small and efficient power houses. More power to them. 
Again, one experience with ICE modules cannot possibly speak for all Class D amps, just the one amp you heard. Goodness folks. I heard a poor tube dac once so they all must have a ways to go.....crazy thought process correct? 
Again, one experience with ICE modules cannot possibly speak for all Class D amps, just the one amp you heard. Goodness folks. I heard a poor tube dac once so they all must have a ways to go.....crazy thought process correct?
These issues with amps that use Ice modules are well documented on this forum. Amps using NCore, Pascal, and Abletec are generally viewed as favorable. NCore is often times described as similar to Ice, but improved. Plenty of folks don't care for NCore though...None of these Class D amps are as universally agreed upon compared to Class AB offerings from McIntosh or Mark Levinson.  
Kvetching does not equal documentation.

The latest generation of ICEPower (AS or ASP) are wonderful, and to my ears indistinguishable from good A/AB amps.

Any attempt to use them as examples of Class D inferiority is highly suspect to me, based on experience.

I'd be happy to evaluate vs. nCore or Pascal when some one provides me the funds... :)

Best,

E
The Teac I mentioned that supposedly used an ICE module was virtually un-listenable. I will admit that I only burned it in for a few weeks, perhaps not enough for a class D.

This D-Sonic uses a modern Pascal module for which I read has technical wizardry that goes way over my head in order to reduce switching noise even further than previously accomplished. When it doesn't sound like trash, I do appreciate the extra resolution and cohesion in the face of difficult passages. I guess I'll just have to be patient.

But, damn, this is the first time I've experienced fluctuating quality during burn-in. I'm very used to burn-in, but there's always a linear progression from "horrid" to "good".

Very interesting point about switching frequencies… What is the acceptable switching friequency range is targeted by the pundits?

 

Given that break-in of a class D power amp ranges from 600 hours to approximately 1500, asking a manufacturer to exercise the device for upwards of a couple of months before shipping it to a dealer may be woefully unrealistic… Of course, everything is possible…. For a commensurate list price uplift.

 

G.



It's just that...jeeze...1500 hours...damn. I thought waiting for the Furutech outlet to break in (800 hours) was savage...
Madavid0 - 

Have you considered the possibility that A) you have very neutral and revealing speakers plus B) a highly detailed and resolving amp could mean that C) perhaps you're just now able to hear the quality of the source recordings that you haven't before?

I remember when I first setup my highly revealing and resolving system how many recordings I used to enjoy sounded poor (accurate) and how many I had previously dismissed sounded great (accurate).

Give your ears time to burn in as well.

Greg