computer audiophile on the cheap Class D amplifiers, can a chip sound as good as a regular amplifier?

[Silly goose]

9 minutes ago, bigbob said:

Wow...

This is just like attending a Green Party meeting, where the argument is about process..

I hear by grant all courteous requests. But they must be in triplicate, with each respondent fighting over who gets the pink and who gets the yellow.. the white copy is to sent when you file form 899(a) to the proper channels.

Carry on.

Well I think this goose is about cooked. It was a fun experience anyways. Time to enjoy some tunes!  

[Jud]

11 minutes ago, bigbob said:

Wow...

This is just like attending a Green Party meeting, where the argument is about process..

I hear by grant all courteous requests. But they must be in triplicate, with each respondent fighting over who gets the pink and who gets the yellow.. the white copy is to sent when you file form 899(a) to the proper channels.

Carry on.

 

My apologies for sidetracking your very pleasant and informative thread, BigBob.  I'll make use of the ignore list to avoid this happening again.

[Ralf11]

10 hours ago, firedog said:

... " for $2k you get an amp which is as good as conventional amps costing $10K"; maybe not as good as the very best A/B implementations out there, but close, and for a lot less money. 

 

 

I want to know if a $2,000 Class D amp will be better sounding than a $3,000 Benchmark AHB2, which is Class ____  (well, I guess we could call it a modified AB)

[bigbob]

43 minutes ago, Jud said:

 

My apologies for sidetracking your very pleasant and informative thread, BigBob.  I'll make use of the ignore list to avoid this happening again.

 It has been informative. I know more about Class-D, and Class-A and I  bowed out after listening to the Nobsound for about three days and went back to the Harman-Kardon. $40 doesn't get you Medium, much less High fidelity. But that was five pages of replies ago. I might try my hand at soldering a Pass Kit Class-A pair of mono blocks for $269--  definitively a "Computer Audiophile on the Cheap" project. After the name-calling and genital comparisons, most forum threads revert back to third grade playground rules, and girls have cooties...But I have my Cootie Mark so I can still play with them-- girls that is. If you want to ignore the thread, that has always been your choice, as for $50,000 Class-D amps...not so much.

[bigbob]

54 minutes ago, Silly goose said:

Well I think this goose is about cooked. It was a fun experience anyways. Time to enjoy some tunes!  

 

I read this and see my notifications, but nothing gets between me and my music...

[Supperconductor]

3 hours ago, bigbob said:

Wow...

This is just like attending a Green Party meeting, where the argument is about process..

I hear by grant all courteous requests. But they must be in triplicate, with each respondent fighting over who gets the pink and who gets the yellow.. the white copy is to sent when you file form 899(a) to the proper channels.

Carry on.

"I refuse to be a member of any organization that would have me as a member."

 

- Groucho Marx

[Supperconductor]

I don't really have a dog in this race. Well, I've bet on every dog since I've liked a lot of amps based on many different technologies, but just thought I'd add this:

 

"Its use of a PWM output stage doesn't seem to have compromised the Classé Sigma 2200i's measured performance, and the amplifier offers high power in an attractively lightweight package."
Read more at http://www.stereophile.com/content/classé-sigma-2200i-integrated-amplifier-measurements#EhX0M5ecUHki57ET.99

 

These days, regarding measurements, I find it interesting when one can correlate measured behavior with listening impressions, but that's as far as it goes. I don't listen while watching an oscilloscope. Many SET's measure TERRIBLY but I find them quite seductive in the right musical & system context. And very few speakers and headphones measure as well as the "worst" amplifiers.

 

There are amps of course that minimize compromises but I've long since abandoned chasing diminishing returns. I'm more likely to try and buy the latest Class D designs because I can indulge my upgraditis and keep my wife & house.

[Jud]

3 hours ago, bigbob said:

If you want to ignore the thread, that has always been your choice, as for $50,000 Class-D amps...not so much.

 

No my friend, you greatly mistake my meaning.  I am very interested in this thread and continued "Computer Audio on the Cheap" adventures where we can all enjoy ourselves and learn much.  (I will be particularly interested if you do decide to build those Pass amps.) The ignore list is a facility open to every user that prevents him from seeing posts by other designated users if (as in my case) he finds that interplay with these other users may distract him from staying on topic in our forum threads.  It's that facility I've made use of, in order to help myself and everyone else continue to enjoy the discussions in this thread.

[unbalanced output]

4 hours ago, Jud said:

 

I am happy to see measurements of these inaccuracies or their effects.  What particular types of common (or even uncommon) distortion measurements would you expect to be affected by these inaccuracies?

 

Good luck with that. Digital domain systems work in the z plane and are not trully analysable in the frequency domain (s plane) afaik. In other words, you cannot "see" the difference between  waves created by a digital and an analog amp with an oscilloscope or a low frequency digital analyser. You need a high frequency digital analyser (and believe in the AD approximation which works quite well).

 

I've found some good readings on Maxim Integrated's website, you may want to check there - they have a good library of articles on the subject. 

 

By the way, DSD works in a similar way - it is a digital representation of an analogue system, and it also cannot be analysed directly in time or frequency domains but mostly by approximations (it is a lot simpler when converting from DSD to PCM which is easily analysable in the frequency domain).

 

If you're handy with Laplace transforms I could try to explain all this in more details, it's not very easy for me to put in simple words from the phone.

 

Cheers

[bigbob]

17 minutes ago, Jud said:

 

No my friend, you greatly mistake my meaning.  I am very interested in this thread and continued "Computer Audio on the Cheap" adventures where we can all enjoy ourselves and learn much.  (I will be particularly interested if you do decide to build those Pass amps.) The ignore list is a facility open to every user that prevents him from seeing posts by other designated users if (as in my case) he finds that interplay with these other users may distract him from staying on topic in our forum threads.  It's that facility I've made use of, in order to help myself and everyone else continue to enjoy the discussions in this thread.

 

I will admit I am prone to over reaction coupled with gross misunderstanding. It's been a weird discussion. I am more interested in the 'body language' of forum discussions. And how people have learned to craft responses so to offer rebuttal but with a dose of Audiophile snarky.

They ban political so what do guys who share a hobby have to talk about. I am learning from what I glean. Yeah the kit looks like a obvious "CAOTC" project. Worse case, I can take it Sasa and have him finish. He fixed a Dynakit from a well meaning dude with no solder skills. I was told in 7th grade shop class, that I have great drafting ability and everyone is safe when I am not near power tools. Cameras no problem, wrenches and screws...Did I mention my drafting..

 

[Jud]

5 hours ago, unbalanced output said:

 

Good luck with that. Digital domain systems work in the z plane and are not trully analysable in the frequency domain (s plane) afaik. In other words, you cannot "see" the difference between  waves created by a digital and an analog amp with an oscilloscope or a low frequency digital analyser. You need a high frequency digital analyser (and believe in the AD approximation which works quite well).

 

I've found some good readings on Maxim Integrated's website, you may want to check there - they have a good library of articles on the subject. 

 

By the way, DSD works in a similar way - it is a digital representation of an analogue system, and it also cannot be analysed directly in time or frequency domains but mostly by approximations (it is a lot simpler when converting from DSD to PCM which is easily analysable in the frequency domain).

 

If you're handy with Laplace transforms I could try to explain all this in more details, it's not very easy for me to put in simple words from the phone.

 

Cheers

 

Thanks, I always like reading, and will look for the ones at Maxim.

 

Do I understand correctly that your characterization of such bitstreams as not directly analyzable in the time or frequency domains would be applicable to any sigma-delta modulated bitstreams, and thus to nearly all DACs made today (which first do 8x oversampling in PCM and then sigma-delta modulate the results)?

[jabbr]

1 hour ago, unbalanced output said:

 

Good luck with that. Digital domain systems work in the z plane and are not trully analysable in the frequency domain (s plane) afaik. In other words, you cannot "see" the difference between  waves created by a digital and an analog amp with an oscilloscope or a low frequency digital analyser. You need a high frequency digital analyser (and believe in the AD approximation which works quite well).

 

 

Not sure what you mean. You would do the analysis post filtering which is an essential part of the DAC as well as Class D amp... what specific analysis are you considering?

 

One issue that I find a bit odd is the idea of DSD256-DSD512 which is then filtered to reconstruct the analog signal (say 100kHz corner 4th order LPF) and then fed into a Class D with then *resamples* at ?100-200 kHz, amplifies, and then refilters, so aside from having 2 analog filters applied, we have exactly the same issues of low bit rate SDM. No? Wouldn't the passive output filter of the Class D amp be subject to all the same issues we are concerned about with DAC output filters that we've gone to such lengths to eliminate with SDM upsampling???

[Silly goose]

3 minutes ago, jabbr said:

 

Not sure what you mean. You would do the analysis post filtering which is an essential part of the DAC as well as Class D amp... what specific analysis are you considering?

 

One issue that I find a bit odd is the idea of DSD256-DSD512 which is then filtered to reconstruct the analog signal (say 100kHz corner 4th order LPF) and then fed into a Class D with then *resamples* at ?100-200 kHz, amplifies, and then refilters, so aside from having 2 analog filters applied, we have exactly the same issues of low bit rate SDM. No? Wouldn't the passive output filter of the Class D amp be subject to all the same issues we are concerned about with DAC output filters that we've gone to such lengths to eliminate with SDM upsampling???

I think this is why it's best to build the system all as 1. But this means no off the shelf chipsets, or modules. Scratch build out of discrete components. 

[jabbr]

17 minutes ago, Silly goose said:

I think this is why it's best to build the system all as 1. But this means no off the shelf chipsets, or modules. Scratch build out of discrete components. 

Certainly. If the off the shelf module or chip doesn't do what you need it to do, or meet a performance you want it to meet, then build what you want, the way you want to build it

[Silly goose]

8 minutes ago, jabbr said:

Certainly. If the off the shelf module or chip doesn't do what you need it to do, or meet a performance you want it to meet, then build what you want, the way you want to build it

Yes to me it makes about as much sense to use a separate DAC together with a preamp and a class D amp, as it does using a DAC with a volume control and robust output stage together with a preamp. But in audiophile land that makes me a fool. Everyone knows you must have a stand alone preamp if you want good sound. A real man is judged by the total length of combined external cabling in his rig. That along with the connector count. 

[Jud]

On 4/17/2017 at 10:34 AM, Jud said:

 

So then you'll want to try to get to the Sonore room at a show if barrows is providing his amp that uses nCore modules.  It'll give you some flavor of the sound of amps like the NORD at around $1500 (not 15,000) for the stereo model and not a huge amount more for a mono pair.

 

For anyone who might actually care what I would think about the NORD amp, above is what I replied to a question about what to try to hear if you aren't in the market for the $15-20K Mola Mola Kaluga mono amps.  The reason I said barrows' amp would give a listener "some flavor" of the NORD is that if I recall correctly his amp, like the NORD, uses nCore modules.  Thus a listener should get some indication of what non-astronomically-priced amps based on nCore modules can do.  How much the NORD sounds like barrows' own custom amp I don't know, since I have never in my life heard the NORD.  I am certainly curious about it and other similar nCore-based amps.

 

Anyone interested in the provenance of the NORD (and a bit of a glutton for punishment) might take a look at this DIYAudio thread from about p. 42 through 65 or so: http://www.diyaudio.com/forums/vendors-bazaar/281361-hypex-ncore-nc500-build-42.html.  Blizzard is "bavmike."

[Silly goose]

1 minute ago, Jud said:

 

For anyone who might actually care what I would think about the NORD amp, above is what I replied to a question about what to try to hear if you aren't in the market for the $15-20K Mola Mola Kaluga mono amps.  The reason I said barrows' amp would give a listener "some flavor" of the NORD is that if I recall correctly his amp, like the NORD, uses nCore modules.  Thus a listener should get some indication of what non-astronomically-priced amps based on nCore modules can do.  How much the NORD sounds like barrows' own custom amp I don't know, since I have never in my life heard the NORD.  I am certainly curious about it and other similar nCore-based amps.

 

Anyone interested in the provenance of the NORD (and a bit of a glutton for punishment) might take a look at this DIYAudio thread from about p. 42 through 65 or so: http://www.diyaudio.com/forums/vendors-bazaar/281361-hypex-ncore-nc500-build-42.html.  Blizzard is "bavmike."

Do we have a new member of the Blizzard fanboy club?

[Jud]

45 minutes ago, jabbr said:

 

Not sure what you mean. You would do the analysis post filtering which is an essential part of the DAC as well as Class D amp... what specific analysis are you considering?

 

One issue that I find a bit odd is the idea of DSD256-DSD512 which is then filtered to reconstruct the analog signal (say 100kHz corner 4th order LPF) and then fed into a Class D with then *resamples* at ?100-200 kHz, amplifies, and then refilters, so aside from having 2 analog filters applied, we have exactly the same issues of low bit rate SDM. No? Wouldn't the passive output filter of the Class D amp be subject to all the same issues we are concerned about with DAC output filters that we've gone to such lengths to eliminate with SDM upsampling???

 

I would imagine DACs don't have the massive amounts of negative feedback used in the nCore Class D design, and would guess the filtering aspect shouldn't be considered in isolation.  But that is speculation and guessing.

[jabbr]

22 minutes ago, Jud said:

 

I would imagine DACs don't have the massive amounts of negative feedback used in the nCore Class D design, and would guess the filtering aspect shouldn't be considered in isolation.  But that is speculation and guessing.

 

Good point. that loop goes around the digital conversion -> LPF.

[VoicesInMyHead]

As an actual owner of a Hypex NCore NC500 based Nord One dual mono amplifier I can chim in that it's probably one of the most cost efficient things I've ever bought. I was looking at upgrading to a quite expensive integrated amp costing many times more, but then I was hooked by the 100+ pages Nord thread in another forum (starting with audio and ends with a sharp toothed fish), I read it with excitement from start to finish and just couldn't resist doing an "experiment". So instead of upgrading my amp, I actually "downgraded" quite a lot money-wise and at the same time I upgraded my DAC instead. Balancing money back and forth...

 

I had an idea about a neutral powerful amp, with any possible warmth or colouring coming from a LampizatOr DAC only (balanced with volume control). I would say the experiment was very successful and I'm very happy with the result. I do not hear any of the shortcomings one normally thinks about with class D, as lifeless, boring, too perfect etc. I think class D has come a long way, and I'm pretty sure this is only the beginning as well. Just look at the Aavik U-300, which was recently praised as best integrated of the year (not cheap though).

[unbalanced output]

2 hours ago, rikard said:

I had an idea about a neutral powerful amp, with any possible warmth or colouring coming from a LampizatOr DAC only (balanced with volume control). I would say the experiment was very successful and I'm very happy with the result. I do not hear any of the shortcomings one normally thinks about with class D, as lifeless, boring, too perfect etc. I think class D has come a long way, and I'm pretty sure this is only the beginning as well. Just look at the Aavik U-300, which was recently praised as best integrated of the year (not cheap though).

 

Hi, I apologise in advance for getting way out of topic here, but which Lampi model did you get and does it have ss or tube regulator? I'm very curious about how does it sound in a very transparent system since I'm gonna give it a try myself.

[unbalanced output]

Jud, Jabbr, those are excellent questions! I haven't got much time to think about right now, but I'll try to enjoy some pcm streams in the meantime 

[Jud]

Actually, it looks as if design and analysis of PWM-based systems and circuits is pretty nearly prosaic stuff these days, that can be accomplished with well-known tools like Matlab, Simulink, and SPICE.  See for example the following:

 

http://ecee.colorado.edu/~ecen5807/course_material/digital/5807_Digital_Model1.pdf

 

http://www3.nd.edu/~mtns/papers/6448.pdf

 

https://pdfs.semanticscholar.org/5355/3271369715deb1b52db741ee58176a4f4cf8.pdf

 

http://www.intusoft.com/DSP/Designing_Digital_Controllers_Using_SPICE_Z_Transform_Model1.pdf

[Jud]

Now I'm curious whether there's anything in Class D currently available that could be used in a DIY project which wouldn't make your ears bleed and might be price-competitive with the $269 Pass Amp Camp kit.

[VoicesInMyHead]

1 hour ago, unbalanced output said:

 

Hi, I apologise in advance for getting way out of topic here, but which Lampi model did you get and does it have ss or tube regulator? I'm very curious about how does it sound in a very transparent system since I'm gonna give it a try myself.

 

Golden Atlantic, tube rectifier, balanced, volume control. It's difficult to describe how it sounds in words, but as I already said I'm very happy with the combination and don't really miss anything. I honestly think any Lampi model would be a good match.

 

Next week I'll hopefully get a passive preamp from Music First to try and see if it makes any difference. Not that I feel that I need it, but I'm curious to try it...