Good Class D amps ??

[firedog]

10 hours ago, sandyk said:

The intolerant resident policeman does NOT speak for the rest of the members.

 

 

You're right, I don't. But if you think people who see the title of the thread and the OP are looking for what's going on in this discussion recently, you have a lack of ability to see outside your own POV. 

[Rt66indierock]

I have 1,000 kilometers to drive today I expect you guys to keep me entertained.

[Ralf11]

4 hours ago, Rt66indierock said:

I have 1,000 kilometers to drive today I expect you guys to keep me entertained.

 

So, you will be reading & driving at the same time?  Post your plate # and vehicle description so I can call the police.

 

 

As firedog says, stick to the topic.  I would like everyone to focus on the thread topic (see the title and OP).  That way I don't have to delete posts, and the intolerant resident policeboy can go off on his usual rants.

[mocenigo]

20 hours ago, March Audio said:

 

That's quite wrong.  It scientifically demonstrates performance differences which will potentially have impact on the sound.  As I mentioned the manufacturers of your op amps use the same data technical and scientific data to sell the product on, so I'm not sure why you are dismissing it as somehow not important.  Would you choose an amp with high distortion and noise levels? 

 

I have never said your amp doesn't sound good..  Hiwever I have also got plenty of feedback telling me the standard op amp on the nc1200 sounds fantastic. You can look at it on my website and read it if you like. So where does that leave us?  Your uncontrolled subject opinion v someone else's. With respect, that's of little use to anyone because by that standard anything goes, just so long as you personally like it.  That's fine in itself but we all may as well pack up and go home and not bother with the discussion in that case. 

 

My only point is to counter the earlier incorrect implication that different buffers necessarily offer improved technical performance or sound, or indeed that there is something deficient with what's already there in the nc1200. 

 

Please, try to understand what I am saying.

Differences in A DIFFERENT circuit do not necessarily imply measurable of audible differences in the original one - we are talking of the buffers of the NCore amps, in particular I mentioned that the NC500 was often paired with the "evaluation" buffer that was noisy and harsh sounding. Clearly the NC1200 has a difrerent one on board (it is not on a separate one by default), and the NC1200 in the Kaluga has different capacitors AFAIK in several places.

 

I am sure that your amps sound great. They have excellent components and look very seriously built. I only commented that at the price you sell your NC1200, it cannot have a separate buffer (bypassing the on board one) and separate power supplies for buffer and comparator. 

 

Also, I never talked of improved technical performance, even though what I observe is that IMD is almost never considered in most opamps and I would be very curious to see a comparison based on that. Even Samuel Groner's huge study does not consider that, and it has been a concrete consideration in only a few discrete opamps (such as Weiss's). In my subjective impressions, SI 994 and DEXA are better than the LM4562, but this is just subjective, and I just like the sound more (the amount of detail seems identical to me). But also it was in concrete implementations, and perhaps the differences vanish if power supply and RF rejection are properly takes care of. In theory, with those ridiculously low distortion levels, there should be no difference (assuming the IMD levels are very low as well, something that is not always reported)

 

I never implied you do not know your lore. Please do not imply that I do not know the scientific method. But we all know how it is difficult to apply this to audio, and after all we buy our equipment on subjective impressions, not on measurements. If something I wrote was not clear, I apologise.

 

 Roberto

 

[firedog]

9 hours ago, March Audio said:

 

Oh the irony

Especially in view of the OP’s post. Even double irony, but not apparently what you thought.

[Rt66indierock]

2 hours ago, Ralf11 said:

 

So, you will be reading & driving at the same time?  Post your plate # and vehicle description so I can call the police.

 

 

As firedog says, stick to the topic.  I would like everyone to focus on the thread topic (see the title and OP).  That way I don't have to delete posts, and the intolerant resident policeboy can go off on his usual rants.

 

We trade driving so stop it. 

 

I’m willing to discuss class d amps anytime. I tested many in the early nineties.

[Ralf11]

ok, best Class D amp under $1,000 ...

 

 

[marce]

I agree here, I want to go fully active and need 8 amps! preferably with balanced input...

My bass amp is class D and most seem to be these days, subjectively can I tell the difference from the older valve and transistor amps... Nope and with the controls you have today, you can tailor the sound from clean and precise (dry almost) to heavy and distorted and anything in between... So I think from what class D's I have heard and from my amp experience they can be excellent, look forward to some reviews and any views on pro class D amps, there are lots of them about.

[mocenigo]

6 minutes ago, marce said:

I agree here, I want to go fully active and need 8 amps! preferably with balanced input...

My bass amp is class D and most seem to be these days, subjectively can I tell the difference from the older valve and transistor amps... Nope and with the controls you have today, you can tailor the sound from clean and precise (dry almost) to heavy and distorted and anything in between... So I think from what class D's I have heard and from my amp experience they can be excellent, look forward to some reviews and any views on pro class D amps, there are lots of them about.

I do not know where you are but you can talk to Apollon audio and they may be able to make something custom for you. 
 

 Roberto 

[Matias]

Actually Apollon already have 2 models of 8-channel Hypex based amps on their website:

https://www.apollonaudio.com/apollon-ncmp8200-hypex-based-multichannel-class-d-amplifier/

https://www.apollonaudio.com/apollon-ncmp8350-hypex-based-multichannel-class-d-amplifier/

 

And Nord goes even further allowing you to configure your amp on the website (Apollon probably allows this too by e-mail). Just choose your modules!

https://www.nordacoustics.co.uk/product-page/nord-one-mp-ncxxx-4-8-122-500w-custom-configurable-channel-amplifier-black

[marce]

cool.

The Nord looks nice and at the moment affordable.

Cheers.

[March Audio]

6 hours ago, firedog said:

Especially in view of the OP’s post. Even double irony, but not apparently what you thought.

Honestly I think you need to stop and take a step back. 

 

The OP asks

 

Which are the best Class D amps?

 

Input buffers are a specific choice to be made when buying many makes of class d amp. It directly affects technical performance and sound quality.  It's entirely relevant and on topic. 

 

I won't respond to you further on this. 

 

 

[March Audio]

6 hours ago, mocenigo said:

 

Please, try to understand what I am saying.

Differences in A DIFFERENT circuit do not necessarily imply measurable of audible differences in the original one - we are talking of the buffers of the NCore amps, in particular I mentioned that the NC500 was often paired with the "evaluation" buffer that was noisy and harsh sounding. Clearly the NC1200 has a difrerent one on board (it is not on a separate one by default), and the NC1200 in the Kaluga has different capacitors AFAIK in several places.

 

I am sure that your amps sound great. They have excellent components and look very seriously built. I only commented that at the price you sell your NC1200, it cannot have a separate buffer (bypassing the on board one) and separate power supplies for buffer and comparator. 

 

Also, I never talked of improved technical performance, even though what I observe is that IMD is almost never considered in most opamps and I would be very curious to see a comparison based on that. Even Samuel Groner's huge study does not consider that, and it has been a concrete consideration in only a few discrete opamps (such as Weiss's). In my subjective impressions, SI 994 and DEXA are better than the LM4562, but this is just subjective, and I just like the sound more (the amount of detail seems identical to me). But also it was in concrete implementations, and perhaps the differences vanish if power supply and RF rejection are properly takes care of. In theory, with those ridiculously low distortion levels, there should be no difference (assuming the IMD levels are very low as well, something that is not always reported)

 

I never implied you do not know your lore. Please do not imply that I do not know the scientific method. But we all know how it is difficult to apply this to audio, and after all we buy our equipment on subjective impressions, not on measurements. If something I wrote was not clear, I apologise.

 

 Roberto

 

Hi Roberto

 

In that case we a probably talking on the same lines.  We agree that different buffers don't necessarily offer improved technical or subjective performance. However It does appear that many are convinced that it is the case. 

 

Regarding IMD it is something that hypex make a point of talking about.  Its probably one of the more challenging tests you can give an amp.  However it is actually directly and mathematically related to THD.  If one is bad / good, so will be the other. 

[March Audio]

5 hours ago, marce said:

I agree here, I want to go fully active and need 8 amps! preferably with balanced input...

My bass amp is class D and most seem to be these days, subjectively can I tell the difference from the older valve and transistor amps... Nope and with the controls you have today, you can tailor the sound from clean and precise (dry almost) to heavy and distorted and anything in between... So I think from what class D's I have heard and from my amp experience they can be excellent, look forward to some reviews and any views on pro class D amps, there are lots of them about.

 

Nord built me an 8 channel amp for this purpose some years ago.  Colin will build what you want. 

[asdf1000]

1 hour ago, March Audio said:

Honestly I think you need to stop and take a step back. 

 

The OP asks

 

Which are the best Class D amps?

 

Input buffers are a specific choice to be made when buying many makes of class d amp. It directly affects technical performance and sound quality.  It's entirely relevant and on topic. 

 

I won't respond to you further on this. 

 

 

 

I agree, discussions about input buffers and filtering RF are highly relevant.

 

As @opus101 requested, would like to see your RF measurements shared when you get around to it later.

 

[opus101]

I don't know if classD amp cards come within the remit of this thread (delete this if not) - if so I'd like to give a shout-out for these highly affordable ($11) mono amp modules.

 

https://item.taobao.com/item.htm?spm=a230r.1.14.57.55481672sdIDSt&id=522728785970&ns=1&abbucket=1#detail

 

They don't come with input buffers (Zin ~3.3kohm) and you do need to supply a balanced power supply. Its a very low-cost route to respectable classD sound - you can tweak the card fairly simply to get what I consider to be high-end sound.

[Ralf11]

sure, cards count

[opus101]

Thanks - I should have added that there's no speaker protection on these so I would recommend either using only cheap speakers or find a protection module to strap on the output.

[mocenigo]

8 hours ago, March Audio said:

Hi Roberto

 

In that case we a probably talking on the same lines.  We agree that different buffers don't necessarily offer improved technical or subjective performance. However It does appear that many are convinced that it is the case. 

 

Hi, yeah, I think this was mostly an initial misunderstanding. I tend to write quite exactly what I mean, but I also sometimes assume some context that it not 100% obvious. So there was some fault of mine in that (and yours, of course, I am good at never fully taking the blame 😉 ).

 

Quote

Regarding IMD it is something that hypex make a point of talking about.  Its probably one of the more challenging tests you can give an amp.  However it is actually directly and mathematically related to THD.  If one is bad / good, so will be the other. 

 

Yes, they are mathematically related, but the relation is quite complex, and there is also the particular flavour of TIM. Modelling the behaviour of amps in the case of very complex and quickly changing signals is not easy.

 

In the case of switching amps, these mathematical relations become even more complicated, and they are added to the mathematical relations of non-switching amps, because some components, like the output network, are subject to those. So there may be corner cases – as it was in the past with TIM – and this is also what implicitly Bruno Putzeys seems to address for his new Eigentakt amps. We live in interesting times, Hypex has to work out what to do without Bruno, ICEpower seems to be on a good path, there is Eigentakt now, and I am quite sure Pascal, DAC, NewClassD are not idling...

 

 Roberto

[Vhond]

Interesting topic on DIY forum: Click

 

Interesting topic about people who have built with Purifi: Click

 

 

[photonman]

I just ordered a Nord NC500 MKII with the Sparkos Op Amps.  I am really curious about these amps and after such a hot Summer with having my Class A and A/C working in a push-pull setup, it just seemed so ludicrous. 

 

I like the modular simplicity of these Class D's and their relatively compact box.  The Pass may be up for sale depending on how this Nord performs in my system.  Or I might have a Winter and Summer amp.

[Matias]

@photonman congratulations. They take a few hundred hours to break in, longer than usual, so patience in the first couple of months until they sound their best.

[wgscott]

51 minutes ago, Matias said:

@photonman congratulations. They take a few hundred hours to break in, longer than usual, so patience in the first couple of months until they sound their best.

 

Extended return period?

[photonman]

3 hours ago, wgscott said:

 

Extended return period?

No, the usual 14 day return policy so I will have to play music 15 hours a day

 

[emcdade]

Whenever someone tells you a piece of gear requires hundreds of hours of break-in that usually means it will still sound like a freeze dried turd.  That’s been my experience anyway.