Class D is just Dandy!


I thought it was time we had a pro- Class D thread. There's plenty of threads about comparisons, or detractors of Class D.

That's fine, you don't have to like Class D amps, and if you don't please go participate on one of those threads.

For those of us who are very happy and excited about having musical, capable amps that we can afford to keep on 24/7 and don't require large spaces to put them in, this thread is for you.

Please share your experiences with class D amps!
erik_squires
kdude661,200 posts05-02-2017 6:55amGeorge,

Were can a mate get a bi-aural Exostosis operation?
Can it be accomplished in the states or would I have to go down under.

Kenny.
Sorry Kenny missed your post question, a while back.
In Australia I had both done in one hit the first time when I was young and very fit. Mine took 6hrs the first time for both and 3.5hrs for the right again the second time many years later, should have kept that car window shut, dam it.
But it also depends on the doctor, how bad it is and how much stamina the doctors/ anaesthetist/ nursing team have, as one ear can take up to 3-4hrs if really bad.
But it’s worth it, you hear like a bat after it, because the doc said the ear drum and it’s bits are being protected while you have the exostosis, in other words not aging as fast.

BTW of all the surfers I knew throughout my competition days, I was the only who was ever able to get both done in one go.

Cheers George
justmetoo

The Molas go back to 2016 and it should be clear from the many who reviewed them that they live in the warm sound camp: ditto their speaker choices. Not me.

After spending a good bit of time with my Ric Schultz EVS 1200 with dual IceEdge 1200AS modules with LOTS OF TWEAKS, one of which is I had to pay an extra $200 for 2 Kubes, that needed to installed by me, to be butted up against each module upon receipt, presumably to deal with any osculation/vibration. I did as the designer wished/mandated, and though it outperformed every other class D amps in my experience (much older W4S amps, Emerald Physics 100.2SEs with upgraded fuses, Audio Alchemy DPA-1, and PS Audio M700s (best of this bunch), I felt there was more to be had.


Finally, I removed the top cover in preparation to remove the Kubes, and noticed a huge improvement. The overall sound opened up in all 3 dimensions, including gaining speed on the initial attack and a much lowered noise floor; similar experience when I removed the Kubes. I now hear micro-detail that was obscured.

I feel I am hearing it at its best (most revealing) and can finally compare it to my Voyager GaN amp when it comes


hth

Nothing was addressed to you at all, I was addressing listening99 post.
You can’t let it go sunshine, you really are a cretin

As for heaudio123 and your comment about me having 2 accounts, that could almost be slanderous, put up or shutup!!
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Yes Class D can be dandy indeed.   The evidence is what I am hearing as I type.
My last 'high end' experience was to save power used by my PaasLabs X350.5 and so I had a test in my system with Mola Mola monos (jolly expensive!). 
Double the price (then) of my Pass and sounding, 🤔 weird, flat, punchy with funny enough, NO real authority. 

Money saved, back with the Pass, now paying power bill with a little less pain. Eish! 
Should I repeat this exercise? 🤔 

Answer: Not for some time to come,
maybe not till Kingdom come...?
I'm pushing 74... never mind Chorona and all.
😎 M. 
I heartily recommend the NuForce STA 200 to anyone looking for bargain solid state audiophile amplification, but it does not do well when pushed to 4ohms and below.
Nuforce went back to linear amps, but this is STA200 is just a reincarnation of the budget Job225 from Goldmund. Good little amp but built to a performance level that really doesn't suit down to 2ohms or even below 4ohms, just like Class-D. But probably sounds better to where it can be loaded down to within it's comfort zone.

Cheers George  
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Does georgehifi have two accounts? Rare that two people would get fixated on such a specific thing.
A class D a o into 2 Ohms or less is just ear bleeding, cynical, no depth, headroom is nonexistent,
devialet, and all this super high dollar stuff is just bad!


Well that’s interesting since so many of us routinely listen to 1 or 2 Ohm speakers, I’d like to know what amps and speakers he reviewed to come to this broad opinion. Hahahaha.
@guidocorona I neglected to "follow" this thread, until now, so I’m just getting around to your question... In terms of power, the Moabs are rated to handle up to 900wpc. I’ve run 80wpc and now I’m running 300wpc with an XTZ A2-300. The 80wpc would have been fine, sounded wonderful, but the amp could not handle the 4ohm load. I heartily recommend the NuForce STA 200 to anyone looking for bargain solid state audiophile amplification, but it does not do well when pushed to 4ohms and below. To be more exact, the amp performed just fine, even very very fine, so long as I didn’t ask it to produce much more than 80db on a continuous basis.

Budgetwise, I'm hoping to stay at $2000 or below. I'm presently on a 30day trail with the XTZ, so I'm interested to hear if anyone can boast a superior experience with a different module than what I'm finding in the IcePower.
@arctikdeth I want to invite you to take a particular (Class D) amp you have auditioned and give us a clear evaluation of your experience. I've had my first class D amp for about ten days and I have a very hard time equating your summary point or points with my experience. I tend to be interested in different points of view, but more detailed evidence is needed, if you really want to make a solid case... otherwise, I'm just hearing a very strong opinion; we could all benefit from a carefully constructed and amply (NPI) supported viewpoint...
Class “D”ull while pushed through major companies, is still sub par to my ears!

 A class D a o into 2 Ohms or less is just ear bleeding, cynical, no depth, headroom is nonexistent,
 devialet, and all this super high dollar stuff is just bad!

ive heard, seriously listened, and given numerous chances.

 There’s always something missing!
if you’ve spent 10K or more on a devialet, or another class D amp, and you love it, kudos, enjoy it.

ill stick with my class A  - A/AB/H amps. !

the emotion is just not there. 
My McCormack / Odyssey / Sunfire amps I’ll put up against any class D stuff.
 Hell, even my aging onkyo tx-890 receiver at 125WPC receiver I’ll put up against the class D amps.

 Cheers to all.
my 2 ¢

 
Hello listening 99,

     There are certainly several excellent class D amp bargains currently available for attaining very good performance at very reasonable prices. It sounds like you just purchased a prime example.
     I’ve owned and have heard a wide variety of class D amps in the past 10 years and I’ve noticed some come common qualities shared by the entire group regardless of price. These general qualities are very solid and taut bass, very low distortion, an extremely low noise floor, very good detail and a very neutral overall sonic presentation, with seemingly nothing added or subtracted from the inputted signals.
     I’ve found the most obvious benefit of the better, and more expensive, class D amps is the quality of their mid-range, treble and holographic imaging abilities.
     Currently, some class D amps rival the performance of the best amps available, regardless of amp type. Unfortunately however, the prices of the best class D amps also rival the prices of the best traditional amps.
     Because of this, when I felt the urge to upgrade, I decided to restrict my budget to an amount I could afford but also decided not to restrict my search options to a particular amp type. I still thought a mid priced class D amp, a pair of D-Sonic M3-600-M mono-blocks with Scandinavian Abletec power modules for about $2,100/pr, performed best driving my speakers. I also knew for certain through in-home auditions, that this was thousands less than comparably performing traditional amps.

Tim
Just got my PS AUDIO M1200 monos this week probably will be trading my Nord One Up monos with Rev D input boards in on them unless someone makes me a good offer on them
Thanks for the reflections that might help me dial in my speakers/system from an amplification angle.

So, this is where I am (1): just bought and have been using the XTZ A2-300, which runs off IcePower. Amazingly, the sound signature is NOT much different from my NuForce STA200. It may be, in the Nuforce, that the midband is slightly more rich, more lustrous, but in normal listening, where I’m more into enjoying than critiquing, the differences quickly fall away.

The new XTZ runs cool, supplies more than adequate juice (up to [email protected]), seems to provide a little more shape to instruments within the soundstage than the Nuforce. For instance, the dimensions of the drum set in my favorite ’instrument’ reference CD, Harry Connick Jr’s "Lofty’s Roach Soufflé" is more realistic.

I’ve also noticed micro-dynamics from the XTZ that seem a little more glossed over in the Nuforce. Unfortunately, I think there are huge psychological impacts that arrive with a new piece of gear, and the mind/ears are more vigilant and likely make a bigger deal over presumed new discoveries that might have been equally attractive if someone had fooled me and placed my previous amp in the chain before playing a song I have been cycling for the past several months.

I'm all too familiar with my enthusiasm for the new sexy thing that arrives in the post and how that enthusiasm carries me through the opening phase or two with that sexy new thing.

So, here is where I am (2) ... I’ve paid $500 for the XTZ. It’s great, no problem. However, I know it’s definitely a bargain audiophile product and while it is amazing for the money, I’m wondering if anyone can speak to how IcePower compares to the Purifi module, or the Hypex modules, or Pascal.... I mean, if I can pay an extra $1000 or $1500, would I hear substantive improvement in soundstage, tonal accuracy, vocal purity, etc., or am I just about ’there.’

I know it’s only I that can say for sure, but have any of you studied the differences between these amps and found significant distinctions from one modern class D amp to the next?

Thank you,
Listening99 the criticisms I saw of the vtv amp were just nitpicking.  Their prices are the best, they use nice thick cases sourced from Ghent and it’s in the USA so no customs worries.  It’s a good deal.  If you’re worried about pcb and wiring layout, apollon in Italy is known to be good with that.  But they use cases sourced from hifi2000/modushop which are kind of thin.  I came super close to getting a purifi amp from vtv but I realized I have way too many unused amps in my collection as it is
Hello listening99,

     I’m not quite sure who you’re directing your question to.  If it’s me, I don’t think I’m the best individual to answer your question.       My experience with class D amps has mainly been searching for ones that best drive my former Magnepan 2,7QR and current Magnepan 3.7i main speakers, which are both only about 86db@ 1 watt and much less efficient than your 98db@ 1 watt Tekton Moabs.     The best amp I’ve ever used on my speakers are a pair of D-Sonic M3-600-M class D mono-block amps.  But these amps output 1,200 watts into my 4 ohm speakers, which seems excessive to me for your 4 ohm speakers.     Unfortunately, I have no experience utilizing high efficiency speakers since I was 18, 44 years ago. Therefore, I have very little useful knowledge to share with you except I believe you don’t need to exclude any amps or amp types from your search. Hopefully, you’ll receive some other lower power suggestions from other readers of this thread,  
Tim
     
I heard the PS Audio Stellar S300 amplifier driving some Harbeth 30.1 speakers and was very pleasantly surprised!  I see PS Audio is now introducing their M1200 class D monoblocks, with tube inputs.  I suspect they'll sound awesome!

Hello listening99, what power rating would be ideal for your speakers? ... And what is your budget for an amp?



Regards, Guido

 
listening99

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So, I’ve been pondering and studying class D, from the layman’s perspective (I’m no electrical engineer, can’t solder, can barely find the transformer), for several weeks. I’ve particularly reviewed Wyred4Sound, D-Sonic, Class D Audio, Apollon, Nord, VTV, Emerald Physics and others. I was excited about purifi and discovered a very good deal on the VTV website, but then when I called out for reports on VTV, as little can be found online, I was immediately met with a critical review, claiming that VTV did sloppy work on the purifi amp this person ordered. I came away concerned that I might have to ready myself for repairs, on a new amp, which this other gon’ers amp required.

So, here’s the deal... I have a new pair of Tekton Moabs, which at 98db are efficient. I’m using a Schiit Saga (tube+passive), as well as a Modi 3. I also run a Nuforce STA200, which is delightful for most listening. Unfortunately, it does not pound out the lowest notes when needed, and when I push it into 90db and up, it quickly heats up to a point where it’s obvious the amp is struggling. I want a cool running, efficient amp. I’m sure tubes would sound great on the Moabs, but we hit 93 today, and 105 (and higher) is just around the corner.

...and so, to conclude: Do you have a recommendation for a class D amp that would match well with the Moabs?

Thanks, for your considerations...
Hello naimfan


     There are a lot of good amps of all types.  Whatever floats your boat or tickles your fancy.
     We all need to pick our own huckleberry.
Tim
I've had a pair of PS Audio M700s for a couple of weeks now; I understand them to be "Class D."
They're very good.  I think I prefer the Belles 350A Reference (at least in my room, system, etc.), but I could never say the M700s aren't terrific sounding. 
Hi @jaymark,


You are kind of hitting on a topic I’ve written about here for a bit, which is habit, taste and training our brains to appreciate different things.

For whatever reasons, my brain is wired quite the opposite. I don’t like the sound Pass amps make and often prefer other brands, and many Class D amps.

There’s no right or wrong, you can’t convince me to like a Belgian White ale either. :)

Best,

E
This is a fascinating discussion.  I love tube amps like made by Canary, I have their 160 wpc monoblocks and I am thrilled with my Pass Labs x250.5 amp paired with Don Sach's preamp.

My brain does not appear to be wired in a way that class D amps sound good to me.  Hopefully the technology will advance and I will have another amplifier type to lust after, collect and rotate thru my systems.

VTV amp with the stock opamps before I’ve had McIntosh, Anthem, Micromega. I still have the McIntosh.
Just got my first class D amp, based on the Purfi 1ET400A. I have to admit I am pleasantly surprised with the detail and just boogey factor this little amp does. 
+1naimfan

     Children are not born with biases or prejudices toward any human or amp type, these are both learned behaviors.

Tim

Every time I see a thread like this I remember a scene from the movie Gettysburg - "I take men one at a time.  Anyone who judges by the race [group] is a peawit." 

So it is, I think, with Class D, or A, or B, or any other variant. 
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Yes most techs will not repair Class-D down to component level, too time consuming and difficult to trace faults with these surface mount, multi-layer boards class-D amps have in them. Because everything is is so tightly packed, so they can squeeze them into mini chassis. 
They just want to install complete "expensive" new board/s.
Trouble is many of the manufacturers don't have old model boards in stock.

Cheers George 
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Class D is not digital and there are no "digital" parts in the amps.  Class D uses chips that are easily attainable and will be around as long as parts used in Class A amps.  Here is the rub......if your class D module breaks then it is usually replaced by another module.  They are designed to last years and years and they are inexpensive enough that they can be replaced relatively cheaply.  However, if you paid $2000 for a class D amp today and one of its modules died 10 years from now would you even have it replaced for $300 or would you rather get the latest $500 amp that sounds even better.....they will get better and better and cheaper and cheaper.  This is, of course, the same with class A/B amps.  Imagine buying a $20,000 class A/B amp today and it goes dead in 10 years.......by then you could probably get a $2000 amp that sounds better.....so just have the old amp fixed and try and sell it to someone.  We are reaching the end of the "You have to pay thousands and thousands of dollars to get great sound game"

Now if you have an amp designed years ago by someone now dead and there are not any schematics for it (for instance Spectron Audio....makers of class D amps from 20 years ago)........then good luck trying to get it fixed.  So, just junk it and buy todays even better sounding class D or class A/B amp for less than what you paid for the Spectron......not really a big deal unless you are really cash tight.

Here today gone tomorrow world of digital parts and design would make me seriously think about putting serious money into a product that may have obsolete parts in the future that aren’t available.


I have to say the modules I’ve seen were barely serviceable. I like the sound of the ICEpower modules, but having attempted to service several of them which arrived with broken off caps, it was a real challenge. They are packed tight and with little care for easy disassembly and re-work.

Every other amplifier I've worked on fell apart (in a good way) as soon as I realized where the screws were that were holding it together.
Another thought on class D and design. One must also consider longevity of parts used and future serviceability of current digital parts implemented in its design. Here today gone tomorrow world of digital parts and design would make me seriously think about putting serious money into a product that may have obsolete parts in the future that aren’t available. Unless a manufacturer stock piles enough parts for future service needs your probably looking at Something that’s worthless if it needs repair of digital parts that are unavailable. Even then there’s no guarantees that a manufacturer will still be around to service it.
Nice thread Erik.
I bought the ATI NC528 class D amp to replace an ATI 6012.
Needed more power for the new woofers in my Linkwitz Lab Orion speakers. The Orions need 8 channels of amp. One for each driver. The 528 has linear power supplies.
Someone asked about soundstage depth. My back wall is 20 feet behind the speakers and the soundstage can go well beyond that. The ATI sounds nuanced, has great dynamics and musical ease. Sounds as good as the front end components. Just bought a used phono-preamp. Asked the vendor who is going to sweep that giant soundstage? I used to own a First Watt SIT2. Class A Magic with the right loudspeakers. But the ATI class D with Orions is also magical.

K
I just replaced a Schiit Vidar with a Parasound Zonemaster 2305 and find it a great addition to my system (and I really like the Vidar!).

I can’t speak to the technology points being raised however for myself Class D gives me a level of performance that I could never afford in a Class A, A/B amp.


Interesting.  I would only offer the following on that.  The Vidar measures better in many of the specs like crosstalk and frequency range.  It also costs about half of the Parasound 2350(I don't think there is a 2305, you must mean the 2350).  

I suspect the reason you like it over the Vidar is because it is giving you 3 x the wpc.  You could get 400 wpc if you had 2 Vidars, and ran them in mono, for roughly the same cost as the 2350.  Different strokes for different folks...
+1 atmosphere
     Another prime example of the universal principle that
 georgehifi happens. 

      Due to the vast amounts of prior fecal matter georgehifi has dropped on this Audiogon Forum over the years, an elite group of the world's best scientists currently believe after completing their thorough analysis of this over abundance of raw data, that this principle can be relied upon to such an exceptionally high degree without a single exception that this Principle merits upgrading to a Law, pending peer review.

Tim

+1 Exactly.


If you want to look at another very respected amplifier design that has a residual waveform imposed on the output signal, look no further than the Berning amplifiers. These amps are excellent; they are liked by everyone who hears them. They employ a switching power supply at their output which is modulated (loaded) by the operation of the power tubes. The switching supply thus has the audio signal imposed on its output. The switching frequency is then filtered out, leaving the audio signal to drive the loudspeaker.


If this sounds familiar to those versed in class D amplifier concepts, it should because its a very similar idea!

So how is it that such a respected amplifier as heard by all comers gets a Murphy while class D does not? They both have a residual. The conclusion can only be that the residual is not harmful in either case. 







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dutch12
I recently purchased a used Belles 150A V2 I never thought class D could sound like this after all the negatives I’ve heard...they just haven’t heard the “right” class D equipment I guess.

Sorry to burst your bubble there Dutch old mate. But the Belles 150A V2 is a 150w Class-A/B linear amp, nothing to do with Class-D. https://ibb.co/yn8f6FJ

https://www.stereophile.com/axpona2010/advanced_transduction_belles/index.html

http://www.soundstagenetwork.com/noisy13.htm

And your right the  Belles 150A have a great sonic reputation, probably better than most Class-D, except for maybe the Technics SE-R1.
Stick with it you’ll be happy for a long while, till Class-D rids itself of it’s Achilles Heel. Like what Technics did to combat it with SE-R1, but yet to remain affordable as well, instead of being $20K.

Cheers George
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I recently purchased a used Belles 150A V2 for my second system and I’m amazed at the sound. The rest of the kit is a Luxman C-300 pre, Cambridge Audio CNX V2 streamer, Ryan R620 speakers and Clear Day double shotgun speaker cables and Silnote Audio Morpheus Reference classic interconnects. Every time I listen I have a smile on my face. I never thought class D could sound like this after all the negatives I’ve heard...they just haven’t heard the “right” class D equipment I guess. 
Actually Georgehifi, YOU made the claim the the output of Class-D is not recognizable, and then you compared the switching residue internal or external,
Go back and read a bit more carefully, please🤦‍♂️.

If the Class-D output filter is removed, then "input test signal" (not switching noise as you say) is not recognizable at the output terminals because of the switching noise monsters it.
With the filter in place, it still sad with residual switching noise, but recognizable, as to what’s going into the input.