Class D Amplifiers

[mrvco]

I have the Sphinx v2 and I think it does well in its price range. It replaced a Musical Fidelity M3i and it was a big step-up in my system, far more revealing than the M3i (and has since been replaced by a First Watt J2). The CroMagII is nearly twice the price of the Sphinx, so no surprise that it would be a big step up in its own right. I also have one of the FleaWatt Class-D amps and it's amazingly good for ~$250.

 

 

Just to add to the thread from a personal angle, I recently auditioned the Rogue Sphinx vs. the Rogue Cronus Magnum II powering some Magepan 1.7i's (looking for an inexpensive yet hi-fi integrad for my Legacy Studio HD "computer speaker" setup). I really really wanted to like the Sphinx (I had heard it before w/ Golden Ear's and really liked the combo) and while I do like it, I did not like it as much as the tube circuit of the Cronus. Not exactly sure why because I can not describe the Sphinx as have a hard, digital edge in any real way. Perhaps if it used the updated nCore instead of the older Ucd (but then that would add $cost$).

 

Based on my very limited experience, I wonder if you have to spend more than $5k on class D to get a really good sound - or perhaps I simply like the sound of the good Class A/B and tubes in the sub $5k space...just thoughts

[Jud]

You pulled your Nord monoblocks after just a few days? Mine took about 3 weeks of continuous playing to full burn in. In that time, they completely transformed. In the first two days, I agree, they sounded very sterile.

 

Very interesting (whether it was burn-in or you becoming accustomed to the sound doesn't matter to me). Your system is in your sig. Kilroy, what's in yours?

[crenca]

I have the Sphinx v2 and I think it does well in its price range. It replaced a Musical Fidelity M3i and it was a big step-up in my system, far more revealing than the M3i (and has since been replaced by a First Watt J2). The CroMagII is nearly twice the price of the Sphinx, so no surprise that it would be a big step up in its own right. I also have one of the FleaWatt Class-D amps and it's amazingly good for ~$250.

 

Well, I admit that I do assume that the cost difference (between Cronus & Sphinx) is more in the design/parts used of the circuit - in other words that one of the advantages of Class D is parts cost and thus price at any given SQ level. No doubt I am just buying into the hype/myth however. I do admit that the Sphinx "does well" - and frankly I would be happy with it, I was just a bit disappointed that the Cronus pulled ahead like it did, and in a significant way (I heard the advantage pretty quickly) though I don't want to exaggerate the difference either. I would have liked to do the same comparison w/ the Golden ears (or even better with my actual speakers of course) as they are more closely related to speakers I would use in design/sound. Next time I am in San Antonio I am sure Galen Carol will let me do this.

 

Interesting what you say about the Musical Fidelity - I wondered how it would compare.

 

Right now I am thinking about a Parasound A23, something from Odyssey Audio, or waiting for that new Schiit class A/B 100/200 into 4 ohm to go into production. Problem is, while I heard the Schiit at RMAF I did not make it to a room with the Parasound or Odyssey gear...

[rodrigaj]

Thanks to this thread I have finally decided to spring for a set of Class D monoblocks. As luck would have it, US Audiomart had just listed a pair of 9/10 Wyred4Sound SX1000. I'll listen to them for one month and then decide if I want to keep them. If I do, W4S offers a trade in of $1600 for the new SX1000R and I will move up to those. These will be powering up my PMC fact.8.

 

Now all that is left is explaining this to my wife who has absolutely no interest in audio. After 40 years of marriage, she'll sigh and say "Where are you going to put them". I'll then explain how little room they take up compared to Class A and she'll sigh again and smile. LOL.

[harmonica2]

I've owned both Class A and Class D on the low end (NAD and Nuforce) and listened to them on the high-end at THE Show in Newport over the last several years. In my opinion, both can sound wonderful but in different ways. If you value high-end detail, low noise, and bang for buck, Class D is the way to go. If you value a warm guitar sound and vocals, it can only be perfected by Class A.

For my budget, class D is a more ideal sound. I love how the sound emerges from an inky blackness of silence. The best implementation I have heard (although I can't afford it) is Devialet. In my system, I compensate for a lack of warmth with a Class A subwoofer, and speakers that have a warm-ish signature. I think I will consider a Class A system when I have $3000+ to invest in a DAC/AMP combination, but by then Class D may have evolved further.

[mfsoa]

The Digital Amplifier Company Maraschino Class D amps are very very good.

[blownsi]

Have any of you heard a PS Audio HCA-2? It's quite dated at this point but I still enjoy it very much. It sounds much smoother than many Class A/B designs to me.

[Melvin]

Have any of you heard a PS Audio HCA-2? It's quite dated at this point but I still enjoy it very much. It sounds much smoother than many Class A/B designs to me.

 

No, but I have the PS Audio Trio A-100 and the matching P-200 preamp. I purchased them 6 or 7 years ago and still enjoy the sound quality very much. I use them in the warmer months, leaving my class A/B amp for the cooler weather. I like both.

[Ajax]

Hi Jud,

 

I purchased the Nord One UP 500DM Stereo Power Amplifier (GBP1450) about 3 months ago and I am very happy with it. Power is rated at 400W RMS.

 

My current system comprises Auralic Mini (with SBooster power supply) > Regen > Benchmark HDR DAC (or Meridian Explorer 2 DAC) > Nord One Up power amp > ATC SCM19 speakers

 

I previously had a Parasound 21 Power amp (125W) prior to the Nord and have enjoyed the extra power, the Nord just seems to play music more effortlessly and to quote Barry Diament (wish he still posted - terrific fellow) the amp just gets out of the way. I did not A/B the two amps but the fact that I put the Parasound into storage (will use later in my home theatre system) and kept using the Nord says something.

 

In fairness the Parasound was bought second hand for only US$200 (its about 7 years old) and I paid the equivalent of 10 times that being US2,000 for the Nord.

 

Anyone considering a Class D amp I can recommend Nord, who assemble the Hypex amps in England. Nord is very much a start up company and is run by Colin North who I found a delight to deal with. Tries very hard to do the right thing.

 

Hypex Amps, Abrahamsen Audio, IPL Acoustic Speakers

 

All the best,

 

Ajax

 

 

PS To Alex (Sandy K),

 

Please don't start fights and stuff up threads by trying to stereotype people into camps. It's total BS. With respect to your previous comments I have both a Regen and a Class D power amp. Telling people that they belong in a certain camp and stereo-typing them because they hold certain views is disingenuous and small minded. I don't belong in any camp, I'm an individual with my own ideas on audio, based on my own experiences and learning from others that I respect, as are all here at CA.

[Dev]

You pulled your Nord monoblocks after just a few days? Mine took about 3 weeks of continuous playing to full burn in. In that time, they completely transformed. In the first two days, I agree, they sounded very sterile.

Mine took even longer. Compared to Pass X250.5, the Nords are very neutral with SIL994 opamps. I have found two major improvements with them - 1) connecting directly to the wall outlet using TWL PC and 2) install Audio Magic SHD Beeswax fuse. They both take the Nords couple of notches up. For what you pay, these amps perform very well above their price point.

[gsquared]

Mine took even longer. Compared to Pass X250.5, the Nords are very neutral with SIL994 opamps. I have found two major improvements with them - 1) connecting directly to the wall outlet using TWL PC and 2) install Audio Magic SHD Beeswax fuse. They both take the Nords couple of notches up. For what you pay, these amps perform very well above their price point.

 

Yes the Nords with the SIL994 opamps perform very well and are incredibly resolving, and yes perform well above their price point. I had not heard about the TWL PCs nor the Audio Magic Beeswax fuses. I will have to investigate both further.

 

Did you have the Nords plugged into a conditioner prior to switching directly into the wall? I have an Audience Adept Response ar12 that I have mine plugged into, which was designed to be non current-limiting and I'm very happy with them. But now I'm curious about going directly into the wall. I will definitely do some testing.

 

Thanks for the tips!

[mrvco]

I'm a bit of an outlier though w/ single-driver, 95db efficient speakers. These are the only speakers that I've owned since buying the Sphinx. I had been very happy with the m3i paired w/ more traditional 2 and 3-way speakers.

 

Well, I admit that I do assume that the cost difference (between Cronus & Sphinx) is more in the design/parts used of the circuit - in other words that one of the advantages of Class D is parts cost and thus price at any given SQ level. No doubt I am just buying into the hype/myth however. I do admit that the Sphinx "does well" - and frankly I would be happy with it, I was just a bit disappointed that the Cronus pulled ahead like it did, and in a significant way (I heard the advantage pretty quickly) though I don't want to exaggerate the difference either. I would have liked to do the same comparison w/ the Golden ears (or even better with my actual speakers of course) as they are more closely related to speakers I would use in design/sound. Next time I am in San Antonio I am sure Galen Carol will let me do this.

 

Interesting what you say about the Musical Fidelity - I wondered how it would compare.

 

Right now I am thinking about a Parasound A23, something from Odyssey Audio, or waiting for that new Schiit class A/B 100/200 into 4 ohm to go into production. Problem is, while I heard the Schiit at RMAF I did not make it to a room with the Parasound or Odyssey gear...

[Dev]

Yes the Nords with the SIL994 opamps perform very well and are incredibly resolving, and yes perform well above their price point. I had not heard about the TWL PCs nor the Audio Magic Beeswax fuses. I will have to investigate both further.

 

 

Did you have the Nords plugged into a conditioner prior to switching directly into the wall? I have an Audience Adept Response ar12 that I have mine plugged into, which was designed to be non current-limiting and I'm very happy with them. But now I'm curious about going directly into the wall. I will definitely do some testing.

 

Thanks for the tips!

 

I have two conditioners - Audience ar6-TSSD and SR 10UEF. Initially I tried on both of them but I find going straight to the wall sounds better in terms of bass definitions and overall dynamics - in fact, if you ask Colin, he would also prefer to go straight to the wall. If you are using Au24Se PC on the Audience (which I don't), then it should sound good. Try it both ways and see what you prefer.

[Ralf11]

Is it safe to post another question?

 

When Bob Carver created the Sunfire amps (with tracking down convertors - whatever that is, exactly??), what class should it be considered?

[esldude]

Is it safe to post another question?

 

When Bob Carver created the Sunfire amps (with tracking down convertors - whatever that is, exactly??), what class should it be considered?

Class G or H. If I recall correctly they are more like class H.

 

Sent from my Nexus 6P using Computer Audiophile mobile app

[mordante]

Maybe I've missed it.

 

But are there any class A/D amps. Where the first 5 to 20 is pure class A with an extra 100-500 watt class D. Either tube or SS.

[firedog]

Maybe I've missed it.

 

But are there any class A/D amps. Where the first 5 to 20 is pure class A with an extra 100-500 watt class D. Either tube or SS.

 

Devialet are sort of doing something along those lines. The "music" signal is created in analog, the current (amplification) is applied to it using class D. They call it ADH (Analog Digital Hybrid).

[mordante]

Devialet are sort of doing something along those lines. The "music" signal is created in analog, the current (amplification) is applied to it using class D. They call it ADH (Analog Digital Hybrid).

 

The problem I have with Devialet is that they convert all inputs to digital as far as I know. In the digital domain they do something I don't like (DSP, ADH and SAM). All that is a big NO for me.

 

Don't understand why anyone would like to have their source material garbled up into something that resembles the taste of the amp builder, regardless of what source you use.

[firedog]

The problem I have with Devialet is that they convert all inputs to digital as far as I know. In the digital domain they do something I don't like (DSP, ADH and SAM). All that is a big NO for me.

 

Don't understand why anyone would like to have their source material garbled up into something that resembles the taste of the amp builder, regardless of what source you use.

 

SAM is optional. You don't have to enable it.

ADH is exactly the type of analog-class D combo you asked about. That's exactly what they are doing.

[mordante]

SAM is optional. You don't have to enable it.

ADH is exactly the type of analog-class D combo you asked about. That's exactly what they are doing.

 

Was put of by Devialet. ADH they say it Analogue Digital Hybrid. But class D has nothing to do with Digital.

 

 

The part after the DAC interests me. I would prefer a normal analogue pre amp or even a passive pre amp. I have heard some integrated amps use a passive pre amp. Not sure though.

[Ajax]

The problem I have with Devialet is that they convert all inputs to digital as far as I know. In the digital domain they do something I don't like (DSP, ADH and SAM). All that is a big NO for me.

 

Don't understand why anyone would like to have their source material garbled up into something that resembles the taste of the amp builder, regardless of what source you use.

 

Hi Mordante,

 

I have the Devialet 200 and have recently begun playing around with subwoofers. Can't believe it has taken me this long to discover the enhancement they bring to listening to music.

 

Where the Devialet is brilliant is with its built in software, called the configurator. Amongst other things it can provide a digital cross over that allows you to not only adjust the volume and cross over frequency but more importantly add a delay to your main speakers so you can properly time align them with your sub and keep them properly in phase.

 

I have both the ATOHM G1 and the ATC SCM 19 book shelf speakers, which I am experimenting together with and old AR subwoofer. I am about to purchase a pair of SVS SB 2000 subs, unless someone can convince me there are better subs at a similar price. Here is an article that explains what I am trying to do.

 

Soundoctor - all about subs

 

The Devialet is a very elegant and compact unit that provides excellent features/flexibility and seriously good sound.

[crenca]

Was put of by Devialet. ADH they say it Analogue Digital Hybrid. But class D has nothing to do with Digital.

 

[ATTACH=CONFIG]30547[/ATTACH]

 

The part after the DAC interests me. I would prefer a normal analogue pre amp or even a passive pre amp. I have heard some integrated amps use a passive pre amp. Not sure though.

 

Your post got me thinking about the analogue/digital divide. The Devialet strikes me as a leading/bleeding edge type product - one that is incorporating several "new things" at once. Your interested in one particular aspect (which is simply leveraging the amp piece in an otherwise conventional "analogue" setup), while others (including myself) are more interested in then entire "gestalt" that such an integrad brings (which means close incorporation/implementation of the DAC and "digital" {such as DSP} features with the rest of the product). Obviously Devialet is focused on the latter but perhaps other companies can and will offer what you are after...

[gsquared]

I have two conditioners - Audience ar6-TSSD and SR 10UEF. Initially I tried on both of them but I find going straight to the wall sounds better in terms of bass definitions and overall dynamics - in fact, if you ask Colin, he would also prefer to go straight to the wall. If you are using Au24Se PC on the Audience (which I don't), then it should sound good. Try it both ways and see what you prefer.

 

Your Audience conditioner is the top of the line version, from what I am reading. I don't have any experience with the SR.

 

What TWL PCs are you using with your Nords?

[cjf]

I've been using Hypex Class D amps exclusively for the last several years and have owned a few different flavors. DIY NC400, Merrill Veritas and now Mola Mola Kaluga's. During that time the speakers in use were either B&W 803D2 or my current Magico S3's.

 

The B&W 803D2's were run with X 4 NC400's in a Quad Amp'd configuration as well as with the Merill Veritas Mono's in the standard one per speaker BiWired. In both cases I really fell in love with the sound but I won't lie that it took some getting used to. Both of these amps behave in a similar manner being squeaky clean, dead silent and very powerful. In the end, with this setup I preferred the Merrills and didn't think it could get any better.

 

Then I upgraded my speakers to the Magico's S3's. From the moment they were dropped into my living room I fought with an incompatibility that still puzzles me to this day. This incompatibility resulted in a High Frequency noise being emitted from the Mid/ High Freq drivers at all times, even without a signal being present to the amplifier. I spent months troubleshooting the issue using every possible tactic and combination of connectivity, power and shielding one could imagine to try and get rid of this noise issue to no avail. The speaker seemingly refused to get along with ANY of the Hypex amps I connected to it.

 

I would consider myself a pretty determined individual with a fair amount of excess spending money to perform "tests" with but despite all that I could not find a fix to this very troubling issue which was clearly a very specific problem using this particular Magico speaker and any Class D Hypex amp I tried.

 

After months of trial and error I took a very expensive gamble and purchased a set of Mola Mola Kaluga amps just to see if they had the same issue using this speaker. To my dismay, the issue persisted

 

So being the stubborn fool I am, I began playing with various types of speaker cable (AGAIN!!) refusing to believe a fix didn't exist. In a final Hail Mary attempt I swallowed another very expensive pill and purchased a set of MIT Magnum $$peaker cables to see if there use of network boxes and filters would offer a cure. To my amazment, they worked!! No noise anywhere, dead silent as it was meant to be.

 

Again, being an idiot, and never being happy I decided that maybe I was in the clear to move up in the MIT line to an even better cable than the Magnum MA I use today. This time I went all in and got a set of Oracle Matrix HD 90's thinking that in doing so the previously mentioned issues would still no longer be a concern. WRONG AGAIN!!! The damn noise returned using the "better" cables. Fu**k Me!! Back in went the Magnum MA's and all was right in the world again

 

To make a very long story short, Class D amps can be VERY good when all the stars line up just right assuming your determined enough to ensure that happens or lucky enough to not find yourself with a pair of speakers that are so picky. In honesty, I know this issue would be far less likely to happen to someone using a more common Class A or A/B amp setup (I tested that also) but it's all something to keep in mind. Component pairing issues are VERY real and any piece of equipment can work great in one system and be a total, expensive nightmare in another.

 

With all that said, the Mola Mola Kaluga Class D amps are by far the most impressive sounding amps I have ever owned and I've owned a few very impressive sounding traditional Class A amps along the way. These guys sound quite a bit different than there siblings and are much more "warm" and "present" compared to the other Class D's I have owned. The typical Class D amp complaints don't apply here nor should they at this price point.

 

Now that I have overcome the noise issue I mentioned earlier this combo of Mola Mola and Magico will more than likely be the system I go to my grave with. IMO, it's that good.

 

At the end of the day, in this hobby and at some point you will most likely need to be willing to try many different combinations of equipment before finally stumbling upon that magic combination that does it all, no matter what "Class" of amp is sitting in front of you.

[avta]

Guys ( I think )this is one of the most interesting threads I've read on CA for a while. Thanks.