Good Class D amps ??

[monteverdi]

 

Just now, sandyk said:

 Just remember that many of you would be pitting the very latest technology against a much earlier design  Pass amplifier.

Linear Amplifier design has also further improved in recent years as evidenced by the extremely high S/N of the Benchmark design.

I understand that, and even the newest class D have less good highs than top class A but at least in my case classD is just superior for woofers. I am using for the rest of the frequency spectrum a Devialet D250Pro which is a hybrid design and measures and in my opinion sounds better than any ClassA (orAB). The only linear amp I know of is Benchmark AHB2 amp which has competitive measurements and high efficiency but I never had the chance to listen to them.

Also energy efficiency should as important as sound quality in evaluating amps.

[sandyk]

13 minutes ago, barrows said:

Hahaha, you are making me laugh:

 

1.  Look at the specs, the amp was the X150.5, and no it was not old or anything.  I was the first owner and purchased it new.  

     The Ncore amps are exceptionally low noise.  Anyway can see this in the specs.

 

2.  I did the listening tests of this right here in my own living room, it was easy enough to hear the differences.  And this was 

     was not short term listening alone, I tested over a year long period.

 

Please stop posting this nonsense when you clearly have no direct experience of it, and cannot even be bothered to look at the noise floors, or S/N ratios...  This info is not hard to find, and no i am not going to be bothered anymore to go and look it up for you.  Look at the noise floors with signal, in order to rule out your absurd theories...

Again, I will repeat that there is no valid reason why a well designed recent Linear Amplifier can't at least equal the S/N of your beloved switching amplifiers. This is evidenced by the most recent Benchmark design which claims the highest S/N of any amplifier.

You are pitting the latest and greatest (?) Class D amplifier against the attached !

Give me a break. There are far better Pass designs at higher starting prices.

 

" classaaudio.com.au/index.php?id_product=200&controller=product

1. Cached
2. Similar

The smallest stereo in the X.5 series, offers a nice basic stereo power amplifier......

 

X150.5 / Specifications     Gain (db) 26

     Power Output /ch (8 ohm) 150

Power Output /ch (4 ohm) 300

 

Input Impedance,(Kohms) 30 / 20

 

Leaves Class A @ pk Watts 10

 

Power Consumption (W) 200

 

[sandyk]

7 minutes ago, monteverdi said:

Also energy efficiency should as important as sound quality in evaluating amps.

 

Try telling that to the numerous Vacuum Tube Amplifier lovers in the forum !

[barrows]

Alex, these two amps were contemporaries at the time.  The Pass .5 series was current, as was the NC-400.  It was not some old design against a new one.  Now both makers have newer models, but neither amp is a slouch by current standards either.

 

My comparison was between these two amps, not some other linear SS design which might have a lower noise floor than the Pass, that is neither here nor there is this discussion.

 

I have never suggested that class D amps are the "best", all I have ever said is that the best class D amplifiers currently can equal the best amplifiers of any other topology.  There are lots of amplifiers I admire, some are class A/B, some are class A (predominantly), and some are class D.

The point is that now we have class D amplifiers which are on a level playing field with any other topology for sound quality, and that those who do not  believe this need to open their ears, and get out and listen to some of them while putting their pre-conceived notions to rest.

 

I am still a great admirer of the Pass Labs amps, and if I ever got some much more efficient speakers, I could imagine the current Pass Labs XA 30.8 in my system as well, given that the capitol was available.

 

Actually, at this moment, if someone gifted me a Constellation Inspiration, I would be very tempted to run it in "direct" mode by adjusting my DAC's output stage to suite and be very happy with an A/B amp of very high sound quality (my sub would make up for the slight lack it has in deep bass energy).

[sandyk]

14 minutes ago, barrows said:

I am still a great admirer of the Pass Labs amps, and if I ever got some much more efficient speakers, I could imagine the current Pass Labs XA 30.8 in my system as well, given that the capitol was available.

 

Unfortunately, you chose to offer a comparison of the very latest nCore technology against what is a basic Nelson Pass affordable design with a very limited power in the Class A region of 10W.

I haven't heard this particular Pass amplifier , but I have heard the large Pass Class A 100W (150W ?) monoblocks through a >Au $100K system, which even presented a very real simulation of height in  a 16/44.1 downmixed recording of a Storm from a Chesky Hybrid SACD. It's rendition of the storm made me involuntarily jump.

Given further improvements in the flatness of the distortion spectrum to 20KHZ in future Class D designs, they will undoubtedly command a much larger share of the market. I just don't believe they are quite there yet.

[barrows]

23 minutes ago, sandyk said:

Unfortunately, you chose to offer a comparison of the very latest nCore technology against what is a basic Nelson Pass affordable design with a very limited power in the Class A region of 10W.

The Pass Labs X150.5 was, as I recall about $6K when i purchased it, and it was a current contemporary of the NC-400 modules.  The XA version of this amp, with the higher class A bias achieves about 30 watts of purely class A output before transitioning to class A/B and costs the same, it ultimately lately has bit less total current output though.

The NC-400 modules and power supplies are much cheaper, although of course one must source a chassis.  this is apples to apples except that the Ncore amp is less than half the cost even if you have to pay someone to build it for you.

 

BTW, the Merrill Audio Veritas has about 130 dB S/N, this is the equal of anything out there.  The much acclaimed Benchmark amp achieves good performance, but its specified S/N ratio is a trick as its gain is very, very low.  If it has normal gain of 26 dB the noise would be much higher.  See Stereophile measurements for confirmation.  Still it does have some interesting engineering.  Never heard one myself.

 

Stop making excuses.  I presented my actual experience.  Pass Labs produces both the X series and the XA series amps because they know that some customers want one kind of sound and some customers want another.  the amps are virtually identical except for bias levels and ultimate output power power.  They two flavors of the same thing: vanilla or chocolate.

[Ralf11]

I like the irony of someone who continually posts about listening experiences (of others, who told him they could hear differences in 2 files) despite what scientists and engineers state is not possible, and then suddenly shifts gears right here...

[sandyk]

13 minutes ago, barrows said:

Stop making excuses.

 I'm not the one making excuses.The facts remain about the huge increase in distortion figures to 20KHZ with the nCore amplifiers that you refuse to accept can affect transparency.

 I tried to be conciliatory and meet you half way in my recent post, but then you just had to come back with this comment, didn't you ?

 

 I am  out of this fanboi thread. I will leave you to GUTB.

 

[esldude]

41 minutes ago, sandyk said:

 I'm not the one making excuses.The facts remain about the huge increase in distortion figures to 20KHZ with the nCore amplifiers that you refuse to accept can affect transparency.

 I tried to be conciliatory and meet you half way in my recent post, but then you just had to come back with this comment, didn't you ?

 

 I am  out of this fanboi thread. I will leave you to GUTB.

 

Huge increase is relative depending upon your perspective.  

 

Something with .1 or even .2% at 20 khz isn't all that large (and you'll not hear it because all harmonics are ultrasonic).  

 

Huge increase from .1% to 2% is getting up there which you might get in some gear like tube amps.  Or they might even run along at 1% at all frequencies at high power with no increase. 

 

So going from .0003 to .1 % is a huge percentage increase, but still small potatoes. 

 

Staying at 1% is no increase in percentages and yet larger than the "huge" increase of class D amps.  

 

While something stays below .01 % THD at high frequencies is better performance I don't think it is audibly different than one which rises to .1% or manages .001%.  

[Sam Lord]

1 hour ago, sandyk said:

...the huge increase in distortion figures to 20KHZ with the nCore amplifiers...

 

 

As esldude said, there is no such thing.  And the very careful differential layouts of both the SMPS  and the amp modules have kept RFI and EMI amazingly small, though certainly worse than conventional designs.  Let's remember that all supplies are switching at the rectifier or choke stage (okay 60Hz vs ~400kHz).

I still have 4 nCore400 modules+SMPS and 4 Ghent Audio mono chassis sitting in a box after 2 years.  I just never got around to all the chassis drilling and wiring rework that I want to do them _properly_.  My ears are now shot, so I'll probably sell them.  ALL of the nCore400 chassis, including even from Hypex, were carelessly laid out: long AC input runs and long source and output leads.  Stupid!  With proper hole drilling of the very same half-width chassis, you can get the AC input to 4" long, PS outputs to 4", input leads to just 1" and outputs to <2" long, all while maintaining 6mm+ clearances.  The Ghent cases are the best, allowing a decent orientation option for the modules.  Anyhoo...

 

When my current Icepower amps die, old 1st generation 150wpc Bel Cantos, I'll probably get 4ch of NC500 amps.  Those measure worse but by all accounts sound better than the NC400s and have more voltage swing at 8 ohms.  Pre-built these now cost about $5k using the premium monoblocks from Nord, or a pair of stereo Merrill Taranis amps.  The Nord stereo amps have a LOUSY layout with silly-long internal leads, so I won't even consider them.  Well, at least Nord takes care to twist the wires well.  Barrows surely appreciates this. 

I do love the green aspect of Class D amps.  And my Bel Cantos have very low noise, excellent dynamics, and quite undistorted sound across the spectrum; I haven't reached their potential yet, though they are by all accounts a big step down from the aforesaid nCores.  For example, I hear _enormous_ SQ increases from using HQPlayer to upsample redbook to DSD128 through the DAC of my Oppo 105D.  Sigh, my old company made better SS amps, insanely good, but they were very expensive.  In those systems we were exploring the noise of EVERY redbook file we had: we found the _end_ of redbook's resolution.

Somebody mentioned the newer output devices with compensating emitter diodes.  They were a big improvement when they arrived some 12-15 years ago.  They improved on the excellent Motorola MJL3281A(NPN) and MJL1302A(PNP), which themselves were 10x(!) as fast as old TO3 devices.  The new TO247 package was a big part of that speed increase.  The newer diode versions were MJL4281 and MJL4302, respectively, and they are still top parts.  Their parameters are better still, especially in gain and max voltage.  Their goal was to eliminate the need for costly emitter resistors, which they did, but some compensation is still advised.  I'm not sure what form that takes: John Stronczer of Be Canto mentioned that he uses a special device or circuit to keep them sweet and clean.   

[audiobomber]

I have limited experience with Class D amps. I bought a Crown XLS-1000 to replace the plate amps in a pair of subs. It was great for that purpose. I tried it full-range driving the main speakers and couldn't pull it out fast enough. Just awful, worst sounding amp I've ever heard in my system. 

 

I use a Topping TP-21 in a secondary system. It does fine there, warm sounding, lacks punch and rhythmic drive. Adding a preamp and opening up the passive volume pot made a big difference. I haven't tried it in my main system. Power is rated at 25wpc in the specs but they're playing games. If specified properly (8 ohm load, both channels driven, 0.1% distortion), it is a 5W amp. 

 

 

 

 

[sandyk]

Just now, esldude said:

While something stays below .01 % THD at high frequencies is better performance I don't think it is audibly different than one which rises to .1% or manages .001%.  

Dennis

 Just briefly, before I leave this Fanboi thread.

If I posted figures like those shown on page 1 of the other thread,for distortion vs. Frequency with my 15W Class A amplifier,

or any other Linear amplifier for that matter, you would just about wet yourself laughing , and tear it to shreds in your reply post !

 Because you own a Class D amplifier you make excuses for the same deficiencies, claiming they can't compromise transparency.

I have yet to previously see you let go of measured deficiencies so obvious with any other type of equipment.

 You would rip the design to shreds and claim that it couldn't possibly work as well as many claimed, possibly quoting Archimago and posters in other forums as well.

 

Alex

[esldude]

Just now, sandyk said:

Dennis

 Just briefly, before I leave this Fanboi thread.

If I posted figures like those shown on page 1 of the other thread,for distortion vs. Frequency with my 15W Class A amplifier,

or any other Linear amplifier for that matter, you would just about wet yourself laughing , and tear it to shreds in your reply post !

 Because you own a Class D amplifier you make excuses for the same deficiencies, claiming they can't compromise transparency.

I have yet to previously see you let go of measured deficiencies so obvious with any other type of equipment.

 You would rip the design to shreds and claim that it couldn't possibly work as well as many claimed, possibly quoting Archimago and posters in other forums as well.

 

Alex

Find an instance of me doing such a thing.  I don't think I would on something that hit a tenth or two at 10 khz and above.  I might if it occurred at lower frequencies because they might under some circumstances be audible.  And I have said, it would be better performance if that didn't happen.  Yet I don't think it a real big audible thing.  

 

Closest I can recall is how some tube amps of moderate power quote a bandwidth at 1 watt and 1 % distortion with less bandwidth and more distortion at higher powers.  And yet I also have said I enjoy the sound of those despite those numbers. 

[sandyk]

Just now, esldude said:

Find an instance of me doing such a thing.  I don't think I would on something that hit a tenth or two at 10 khz and above.  I might if it occurred at lower frequencies because they might under some circumstances be audible.  And I have said, it would be better performance if that didn't happen.  Yet I don't think it a real big audible thing.  

 

Closest I can recall is how some tube amps of moderate power quote a bandwidth at 1 watt and 1 % distortion with less bandwidth and more distortion at higher powers.  And yet I also have said I enjoy the sound of those despite those numbers. 

 

You conveniently ignore your attacks on the USB Regen which had pissy little artifacts at levels you consider are well below audibility .

 Anyway, carry on with your preaching to the converted.

[esldude]

Just now, sandyk said:

 

You conveniently ignore your attacks on the USB Regen which had pissy little artifacts at levels you consider are well below audibility .

 Anyway, carry on with your preaching to the converted.

I don't think I said the Regen had audible issues.  I think spending money on something promising a cleaner USB signal or cleaner analog results from a USB fed DAC which instead makes the signals worse is not a testament to its worth.  Leave out the Regen and get a cleaner analog signal.  That I might have said. 

[barrows]

2 hours ago, sandyk said:

 I'm not the one making excuses.The facts remain about the huge increase in distortion figures to 20KHZ with the nCore amplifiers that you refuse to accept can affect transparency.

 I tried to be conciliatory and meet you half way in my recent post, but then you just had to come back with this comment, didn't you ?

 

 I am  out of this fanboi thread. I will leave you to GUTB.

 

OK Alex, I am done as well.  You praIsed the subjective listening experience of Pass XA Series amps, see figure 7 of these measurements of the XA 60.8:

 

https://www.stereophile.com/content/pass-laboratories-xa608-monoblock-power-amplifier-measurements

 

Hmm, I see a large rise in distortion at high frequencies to levels much more than those of any of the good class D amps out there.  Now take a look below at the performance of the current SOTA amp module from Hypex/Ncore.

Everytme I give evidence your seem to shift the discussion to something else.  I would suggest you listen to Mola Mola Kaluga in a good system/room, with a nice pair of speakers which are a good match, my choice would be Vivid Audio Giyas.  Your bias is so strong you cannot see the forest for the trees.

 

NC500-OEM-datasheet-R4.pdf

[sandyk]

Just now, barrows said:

Your bias is so strong you cannot see the forest for the trees.

 

I only mentioned the 100W Class A because you mentioned the one you owned that went to 10W in Class A

 Attached is very similar to what I personally use.

 That's what a genuinely transparent amplifier should measure something like .

BYE !

[Forehaven]

Can you build one of these NCore amps and use a linear PS instead of SMPS?  JC

[Kal Rubinson]

Just now, Forehaven said:

Can you build one of these NCore amps and use a linear PS instead of SMPS?  JC

Yes.  The ATI and Theta nCore-based amps use LPS.

[firedog]

19 hours ago, GUTB said:

 

I’ll note that no one with high end systems prefers class D.

You continually manage to make up these absolute statements that are true only inside your head. 

Please provide proof of statement other than your prejudiced impressions of what you read. 

[barrows]

45 minutes ago, Forehaven said:

Can you build one of these NCore amps and use a linear PS instead of SMPS?  JC

Sure, but the performance would be no better...  The SMPS 600 is designed specifically for this amp module and is essentially "perfect" already.

 

SMPS are not inherently "bad" as long as they are well engineered and implemented.  Chord uses them in their amps/DACs, and Meitner/EMM in their DACs.  They just get a bad rep from all the cheap wall warts around.  Like any circuit design they can be done well by good engineers.

[GUTB]

1 hour ago, firedog said:

You continually manage to make up these absolute statements that are true only inside your head. 

Please provide proof of statement other than your prejudiced impressions of what you read. 

 

Keep in mind that I’m neurotypical. “No one” is hyperbole; I’m sure there must be someone with high end gear up who prefers class D. You’ll look for a long time for someone with a MSB Diamond V, Magicos, VAC Statement, Rockports, etc, who prefer class D for amplification.

 

Class D systems failed to impress last year at AXPONA, so let’s see what they accomplish this year? Fritz, speakers which I respect (and own) will be showing with a Wyred4Sound class D this year so I’ll have a listen.

[GUTB]

58 minutes ago, barrows said:

Sure, but the performance would be no better...  The SMPS 600 is designed specifically for this amp module and is essentially "perfect" already.

 

SMPS are not inherently "bad" as long as they are well engineered and implemented.  Chord uses them in their amps/DACs, and Meitner/EMM in their DACs.  They just get a bad rep from all the cheap wall warts around.  Like any circuit design they can be done well by good engineers.

 

SMPSs are inherently bad.

[Ralf11]

Transistors and tubes are inherently bad, so are speakers.

[GUTB]

2 minutes ago, Ralf11 said:

Transistors and tubes are inherently bad, so are speakers.

 

Neurotypical, please, There’s no alternative for speakers or transistors,.