Good Class D amps ??

[oneartist]

Paul of PSAudio says the M700's are about 90% as good as the 250's but the 250's are more than twice the price. The M700's are just fine for my ears. They are in total control of my big Maggies. 

[jmpsmash]

18 minutes ago, ShawnC said:

I have a pair of M700s.  It's the only class D I've tried at home.  When compared to my my Emotiva XPA Gen2 stereo amp, the M700s go deeper with the sound stage and more defined in the midrange.  They are also louder.  Where they do lack is in the treble range.  Not as defined as any other class A or AB amp I've had.  I just bought PS Audio BHK250 amp.  That arrives in the next week, so I can compare the M700 to the 250.  I'd also consider Bel Canto's class D amps, from what I've heard at the dealer they are superb but cost more then M700s. 

 

Thanks for the feedback. Interesting that you mentioned the treble being not as defined. Can you elaborate? Is it harsher sounding? or lack of treble? or something else? My NC400 don't have a very smooth treble either, it does reach high, not harsh per se, but definitely not silky smooth.

 

After one of my NC400 died, I took out my old amp which is a Bel Canto S300. Quite old and early generation class D from Bel Canto. I cannot vouch for the Bel Canto sound though. In my experience with the S300 and the Dac3.5vb, I noticed Bel Canto's sound tend to be darker and bland.

[GeneZ]

This thread was started way back in March.  Since then, a new level of Class D amplifier has made its debut.  From the reviews I have seen so far its been able to create its own class in how it sounds.

 

It has a 1M Ohm input impedance.  No chance of any preamp mismatching with that unusual rating.  I own a Nuprime ST-10, and have never tired of it.  This new Nuprime amp is supposed to surpass it in a beautiful way.  I am not complaining that I do not own this new amp.  But, if some here are looking for something that stands above in a way that is not just rhetoric.. This may be what needs to be auditioned.

Nuprime Evolution amplifier

 

Nuprime Evolution One

[jmpsmash]

The NuPrime Evoluion One looks fantastic. But unfortunately out of my budget.

 

The ST-10 however, look more in my ball park. My dilemma is whether to just fix the Hypex NC400 and keep it, which cost around $400 or so, or try the NuPrime ST-10. Anyone have comparison of those two?

 

Looks like my option so far is one of:

- fix Hypex

- NuPrime ST-10

- PS Audio Stellar M700

 

 

[wgscott]

Fix the Hypex.

 

NuPrime won't publish measurements.  Don't believe the hype.

[GeneZ]

2 hours ago, jmpsmash said:

The NuPrime Evoluion One looks fantastic. But unfortunately out of my budget.

 

The ST-10 however, look more in my ball park. My dilemma is whether to just fix the Hypex NC400 and keep it, which cost around $400 or so, or try the NuPrime ST-10. Anyone have comparison of those two?

 

Looks like my option so far is one of:

- fix Hypex

- NuPrime ST-10

- PS Audio Stellar M700

 

 

Well... right now I also have a PS Audio Stellar S300.  Its the little brother of the M700.  The PS Audio is going for sale this winter. The Nuprime stays.  Both are very good.  If I never heard the ST-10 I would not have a problem with keeping the PSA.

 

The first thing I thought of when listening to the ST-10 was how it reminded me of my old McIntosh MC275 in the bass, only tighter.   It has a certain tubish quality to its sound.   It feels right at home with a good tube preamp.

 

I don't know if that tells you what you need to know.

[GeneZ]

54 minutes ago, GeneZ said:

 

deleted

[GeneZ]

2 hours ago, wgscott said:

Fix the Hypex.

 

NuPrime won't publish measurements.  Don't believe the hype.

 

Curious...  What specs did you need beyond what they gave on the Nuprime page?  

 

Did you click on the Specs tab? https://nuprimeaudio.com/product/evolution-one/?v=7516fd43adaa

 

I would not recommend it because of its price.  What I really wanted to do was to make others aware of this interesting new Class D amp that is new on the market. Nuprime makes their own modules. They do not but OEM modules form the big two and build around them. I became aware of this when years back I purchased my first Class D when there was NuForce.  On a right system they lend themselves to a midrange transparency that I find intriguing.

 

To each his own.

[mocenigo]

7 hours ago, jmpsmash said:

Has anyone compared the PS Audio Stellar M700 and the Hypex NC400?

 

I had the NC400 for more than a year and I love the detail, neutrality, dynamics and esp how it manage to control the woofer so well. Unfortunately my NC400 just blew (totally my fault) and I am thinking of moving to the M700 but I don't know if it will retain the same qualities. They will be driving a pair of Mezzo Utopias.

 

The PS Audio M700 uses ICEpower 700AS1 modules, which already have a gain of 27.4 Db and an input buffer. So they add an additional buffer to modify the sound, and I guess their "analog cell" is just impedance adaptation, addition of a sound signature, with unity gain. In general the Hypex NC400 and NC500 modules are considered superior to the older ICEpower modules (there are new ones, the 1200AS1and 1200A2 that are preferred by many, and are based on a completely new technology with respect to the rest of ICEpower's product palette). Also, the ICEpower modules integrate power supply and amplification on the same board.

In my humble opinion it makes more sense to ditch the voltage amplification stage of these integrated modules, in other words going from NC400 to NC500, and have a separate power supply (which can reduce interference). Also, adding a buffer to an already complete amplifier makes little sense it is sound character tuning. So it is better to have an input stage that has all the same characteristics as the "analog cell" (class A, discrete, maybe with a modular structure) but also has its own gain, with the result that the signal has to pass through less components.

I would therefore opt instead for a NC500 based amplifier with a buffer stage and replaceable opamps (such as the excellent discrete ones from Sonic Imagery, Sparks, Burson, or DEXA) so that you can also very easily change the sound signature to better match the rest of the equipment. I sourced mine from Apollon Audio, which are also very well built, with a clean organisation inside. But there are also other manufacturers, depending on your geographic location. 

 

I am not affiliated with Apollon Audio - I only have talked a lot to the owner of the company when I was thinking which amp to buy and how to customise it, and am a very satisfied customer.

 

 Roberto

 

[ShawnC]

10 hours ago, jmpsmash said:

 

Thanks for the feedback. Interesting that you mentioned the treble being not as defined. Can you elaborate? Is it harsher sounding? or lack of treble? or something else? My NC400 don't have a very smooth treble either, it does reach high, not harsh per se, but definitely not silky smooth.

 

After one of my NC400 died, I took out my old amp which is a Bel Canto S300. Quite old and early generation class D from Bel Canto. I cannot vouch for the Bel Canto sound though. In my experience with the S300 and the Dac3.5vb, I noticed Bel Canto's sound tend to be darker and bland.

As far as the treble goes, I'd say it's the lack there of.  It just doesn't seem to shine.  Cymbals don't sound right, it's dull.  Some like it like that.  Only my best recordings sound good, not great with these amps.  With my Emotiva amp everything sounded pretty good but my best recordings sounded great as they should as a comparison.

 

You have to remember PS Audio made the best class D amp they could at given price point.  There were certain constraints when the design was being developed ie. money.  If you haven't noticed all PS Audio gear is doubled cost of the product below it.  S300 - M700 - BHK250 - BHK300, DSDJR- DSDSR (except the now on sale DSDSr).

 

As far as the Paul saying it's only 10% difference between the M700s and the BHK250 I'll find out soon.  I have a feeling it's just good PR to say that.  With that said, the M700 bass and lower level midrange are glorious as they should be.  Class D excels in this area. If I wasn't getting such an amazing deal on a brand new amp I'd be fairly happy with the M700s.  

 

My friend is borrowing my Emotiva amp with his Maggies he hand built himself at the factory (He hasn't worked there for 15 years).  He was surprised how much bass can come out of those speakers with lots of power at their disposal.  He has an older version of the 1. series and has always used tubed pre's and low powered amps.  He'll be getting the M700 to test when I get he BHK in house.

[barrows]

I actually preferred the sound of my NC-400 based amp (with Cardas wiring internally) to the PS Audio BHK.  But this was a preference thing rather than one amp being clearly "better" than the other.  I found a lower noise floor and better detail retrieval with the NC-400, and no lack of high frequency extension.  I have a fair amount of experience with class D, and the Score was the first class D approach I have heard which actually cleared up the high frequency (lack of) of earlier class D amps.

If you like your NC-400 amps, I would suggest looking at some of the NC-500 based amps, likes the Nord, Appollon, etc.

[jmpsmash]

@ShawnC : Thanks for the info. Sounds like I am going to skip the M700. Having a lack of treble is a no-no. and the gain is a bit too much for my speakers anyway, i might not have  fine enough steps on my preamp's attenuator.

 

@mocenigo Yes. I agree. I understand the NC400 is for hobbyist with the input stage while the NC500 is the OEM one designed for that exact usage you mentioned. 

 

The NC400 is really rather impressive. I enjoyed it quite a bit. It has great extension on both ends, grabs the bass really tight, fast, transparent and clarity. It is a really fun amp to listen to. The only issue I have is that there is a little bit of siblance at the top end. I have been enjoying it and wouldn't be looking for something else if I hadn't blew one side of it. I might still fix it and it will be a good comparison to do with whatever I decide to get and I will sell the loser.

 

The ST-10 does sound good from the reviews so far. I might just give it a try. I don't think I will get the DTSS mod yet, the $750 is nearly half the cost of the amp. If the base unit does exceed my expectation and better than the NC400, then I might opt to add that bit of extra at a later stage.

 

The 150w vs 400w is another concern, but I think that's might be ok as my speakers are 92.5dB. so perhaps the extra headroom isn't that important.

 

I'd love try the Evo One, or the BHK to be honest. But even at the top end of my budget I don't think I am ready to put in so much money for them.

 

 

[jmpsmash]

3 hours ago, ShawnC said:

 

As far as the Paul saying it's only 10% difference between the M700s and the BHK250 I'll find out soon.  I have a feeling it's just good PR to say that.  With that said, the M700 bass and lower level midrange are glorious as they should be.  Class D excels in this area. If I wasn't getting such an amazing deal on a brand new amp I'd be fairly happy with the M700s.  

 

 

I swear I saw a recent video of Ask Paul saying he didn't remember saying the M700 is 90% of the BHK. I tried to go look for it but couldn't find it. It was title something like "is class D the future of amplification" and he basically says classD has the issue with the top end. I will post it here if I find it.

 

[GeneZ]

All these people are hearing things 'in the details' that they do not like, and it may not be the amp that is the culprit.  Its always system dependent.  No one can recommend what is best *for you* unless you share everything in your system as identical. They can tell you what is essentially good in certain ways only.  Speakers and their set up can change everything.  Cables can make or break a system.  The PS Audio is essentially a good amp and uses OEM modules.  NuPrimes make their own design and are good amps.  Good luck with your systems. No one can tell you what is going to sound great in your system.  Change your interconnects and you might discover the amp is much better than realized....  Up until then you were blaming maybe the amp, or preamp...or DAC.   

[GeneZ]

1 hour ago, jmpsmash said:

 

I swear I saw a recent video of Ask Paul saying he didn't remember saying the M700 is 90% of the BHK. I tried to go look for it but couldn't find it. It was title something like "is class D the future of amplification" and he basically says classD has the issue with the top end. I will post it here if I find it.

 

 

The moral to the story?   Have some tubes in your system when using D class for its full potential.  BHK uses tubes. 

Don't think that makes no difference between the M700 and its big brother.  I now have a tube preamp with my Nuprime ST-10.  I can see why some say its the way to go.

[jmpsmash]

52 minutes ago, jmpsmash said:

 

I swear I saw a recent video of Ask Paul saying he didn't remember saying the M700 is 90% of the BHK. I tried to go look for it but couldn't find it. It was title something like "is class D the future of amplification" and he basically says classD has the issue with the top end. I will post it here if I find it.

 

 

found it:

 

 

[jmpsmash]

1 minute ago, GeneZ said:

 

The moral to the story?   Have some tubes in your system when using D class for its full potential.  BHK uses tubes. 

Don't think that makes no difference between the M700 and its big brother.  I now have a tube preamp with my Nuprime ST-10.  I can see why some say its the way to go.

 

That's what I have. Tube pre and class D power. I think that's the best combo. Tube tunes the sound, and a "wire with power and dynamics" for the power.

 

[Ralf11]

Gene, what do you find wrong or poor SQ about the PS Audio Stellar S300?

 

and I might be interested in buying it...

[GeneZ]

1 hour ago, Ralf11 said:

Gene, what do you find wrong or poor SQ about the PS Audio Stellar S300?

 

and I might be interested in buying it...

Nothing is wrong.... Its like trying two different cups of excellent coffee. You are just going to prefer one over the other.  The Nuprime has a certain heft that I have only heard with a tube amp. But its much tighter than tubes.  It was tuned that way by its designer.  When my Nuprime was in the shop. I listened to the S300 and I was very happy with its sound.   I just needed to decide which one I am going to keep.  Considering the ST-10 with the TDSS mod cost much more than the S300?  I'd say for what they do, they are both products that you will not go wrong with as long as there is a system synergy with what you own.

[GeneZ]

2 hours ago, jmpsmash said:

 

That's what I have. Tube pre and class D power. I think that's the best combo. Tube tunes the sound, and a "wire with power and dynamics" for the power.

 

A well made class D amp has a quality only heard with tubes. Class D amps control the speaker movement better than tubes can.  The damping factor with the Class D that I have listened with is as good as it gets. 

 

The Nuforce, Nuprime, and PS Audio amps, I listened with all share with tubes a certain transparency in the midrange that I never hear with any AB amp.  Tube preamp... or even a good passive preamp... works well with Class D. 

[wgscott]

14 hours ago, GeneZ said:

 

Curious...  What specs did you need beyond what they gave on the Nuprime page?  ...

To each his own.

 

I was hoping for something similar to compare to p.11 on this:

 

https://www.diyaudio.com/archive/blogs/alexcp/attachments/2245d1486826701-ncore-based-power-amplifier-nc400_04xx.pdf

[ShawnC]

3 hours ago, jmpsmash said:

 

found it:

 

 

I remember reading in one of the threads on their website were he mentioned that 90/10% thing.  This video clears a lot of that up.

 

All admit that I'm a recent fanboy of PS Audio/Paul McGowan.  He's a straight shooter who pokes fun at himself and the industry he works in.  Like in the video, class D has come along way but there's still something that's missing from the design to compare directly to some A/AB design. 

 

As @GeneZ said, much of the sound will be system dependent.  Everytime I go into a local high end dealer they have the Magnepan 3.7i with Bel Canto Ref600m and the sound is fantastic.  I think class D with panel speakers is a no brainer to experiment with.

 

@Ralf11 if your seriously considering some PS gear like the S300, give The Music Room a call and see if they can't make a deal with you or a trade.  I saw the BHK250 used for $3700 last week but they talked me into a brand new model at a steal of a price (still expensive by my taste but I hope it's worth it).

 

The M700s took about 2 weeks to break in with/without music running.  I never turn them off, which is what I like about class D in general, no warm up time.

 

Good luck to all, in your search for better sound

 

Shawn

[GeneZ]

1 hour ago, wgscott said:

 

I was hoping for something similar to compare to p.11 on this:

 

https://www.diyaudio.com/archive/blogs/alexcp/attachments/2245d1486826701-ncore-based-power-amplifier-nc400_04xx.pdf

  They have to give those specs because they are selling OEM modules to builders who will have to build around their module.   Normally you do not get those details when a manufacturer has already created a product to match the amp they are using. NuPrime designed a proprietary type of system that they will even tell you that their map is not really a Class D in the classic sense.   Their amps sound quite tube like. Even the little NuPrime STA -100 I own has a unique sound that I find intriguing.   

 

Here is a clip from a review I located written when NuForce (now Nuprime)  used to take the time to explain how its design is not the same as what we normally see with Class D.

 

 They are based on proprietary circuit topologies developed by NuForce

 - not on any of the popular off-the-shelf Class D amp modules such as

those offered by Tripath, Bang & Olufsen/ICEPower or Philips/Hypex UCD.

Interestingly, the NuForce amps were designed by the company’s chief

technology officer —an engineer named Tranh Nguyen, whose design

accomplishments include development of the power system for the

Tomahawk missile and who holds several patents relevant to

Class D amplification. https://www.hifi.com.sg/review/nuforce_ref9_tas_review.pdf

 

Since that was published Nuprime's designer has not stopped refining his design. 

 

At one point they refused to even be labelled Class D, but apparently did so for the need to establish a position in the market. 

 

This link will take you to their official position on what constitutes Class D.   https://nuprimeaudio.com/guides/amp-design/?v=7516fd43adaa

 

 

No...  I do not work for NuPrime.   I would recommend PS Audio for those in that price range. 

 

I am pretty sure there are other Class D amps out there that are now under the radar. 

 

[iwf]

I’ve used Hypex amps for many years and managed to get hold of a couple of the NC500s to build a couple of mono amps, using Nord input buffers.  I loved tghe idea I could tune the sound based on which op amps i used.

 

needless to say and without any engineering knowledge I’ve found them to be the most natural amps I’ve heard for less then £4K.

 

powering a pair of B&W 805d3 I’ve never been happier

[DancingSea]

I have the S300 paired with a DS Jr DAC, I love the combo and have lost the grass is always greener itch for awhile now...