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Good Class D amps ??


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3 minutes ago, esldude said:

So that is very good, but not quite equal to the Benchmark measurements posted above or the other amp tested by Soundstage.net which btw is the large Bryston mono amp.  The only one to pass  the transparency listening test both sighted and blind by the Swedish AES. 

 But the complete kit, including metalwork for this one is only $749 !!

http://www.altronics.com.au/p/k5165-ultra-low-distortion-mk.3-135w-stereo-amplifier-kit/

 

This old 2011 design can also be further improved by Input and Output device selection !

 An experienced DIY person could markedly improve the measured performance of this amplifier.

 

 

 

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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2 minutes ago, sandyk said:

 But the complete kit, including metalwork for this one is only $749 !!

http://www.altronics.com.au/p/k5165-ultra-low-distortion-mk.3-135w-stereo-amplifier-kit/

 

This old 2011 design can also be further improved by Input and Output device selection !

 An experienced DIY person could markedly improve the measured performance of this amplifier.

 

 

 

Yes, looks like a darn good amp and a super value for what performance you get.  But that wasn't really the topic here.  

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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2 minutes ago, esldude said:

Yes, looks like a darn good amp and a super value for what performance you get.  But that wasn't really the topic here.  

No.

  You are still trying to show just how good Class D amplifiers can  be in comparison with a decent modern Linear design ! :P

 The SC ULD 3 can also be further audibly improved with a simple front end balancing technique, but you refuse to accept  that any further audible improvement can possibly be heard at such already low distortion values !.

 

http://www.diyaudio.com/forums/solid-state/133018-current-mirror-discussion-15.html

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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10 hours ago, Ralf11 said:

Which are the best Class D amps?

 

Has anyone compared them with other designs, Class A or AB, etc.?

FYI, I use a Wyred4Sound ST500 in my system.  I do consider it very good.  I haven't said it is the best amp in the world.  But it will play my Soundlabs better than quite a number of A or AB amps.  But that is a very unusual and demanding load for any amp.  My amp is based upon the IcePower modules and the Hypex and such are considered to be improvements on those.  The IcePower Bel cantos are very good class D amps too.  I preferred the Wyred4Sound to them slightly as they do sound a bit different.  The newest Bel Cantos I think better than either IcePower. 

 

Now prior to the W4S I used a large Conrad-Johnson SS power amp.  The W4S is much better than it.  Previous to the CJ I used a Classe 25 which powered the speakers better, but sounded a little less good imo.  I've heard the big Brystons in another system and they are good, but I haven't gotten to hear other amps in that system. 

 

You also have to be careful about what is class A operation.  I owned way back a Classe DR-3  VHC which was 45 watts class A.  What it really was is heavily biased operating a bit beyond 45 watts class A and then swinging over into A/B with what amounted to around 220 watts.  But sure with nearly all speakers you might never ever hear music except via class A operation even with the Quad ESL63s I had at the time.   I had one of the Pass Aleph amps.  Only capable of class A operation.  Sounded pretty nice, but your speakers had to be a real gentle load or it ran out of current and sounded terrible.   I think the Krell KSA50 was only capable of class A operation.  The KSA 250 I think was like the DR-3, around 50 watts class A and then up to 250 or so AB.  

 

A final note, using REW I've measured my amp and speakers at near the amp's rated power with a bit under .3% distortion at 10 khz in room.  So that isn't state of the art, but it is pretty good. 

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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9 minutes ago, sandyk said:

No.

  You are still trying to show just how good Class D amplifiers can  be in comparison with a decent modern Linear design ! :P

 The SC ULD 3 can also be further audibly improved with a simple front end balancing technique, but you refuse to accept  that any further audible improvement can possibly be heard at such already low distortion values !.

 

http://www.diyaudio.com/forums/solid-state/133018-current-mirror-discussion-15.html

Yes good class D can be very, very good, provide power that few linear amps can match without costing multiples more, etc etc.  

 

Yes, I find it highly unlikely with music any improvement on specs below .1% THD and IMD will be audible.  But with speakers attached and maybe not well matched even otherwise good amps can run afoul of those limits.  So those numbers are thru the speaker as heard.  Your only evidence to the contrary is sighted listening impressions which I find of limited value.  More attention should be paid to distortion heard with speakers attached.  At normal listening levels the differences in distortion you think are audible would be like adding or subtracting an amount of sound that is 30 db below the audibility of human hearing, and with noise in the listening room obscuring it even then. 

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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Bel Canto ref150s, Mcintosh MC202 and 252--all sort of smooth, tonally adequate,but ultimately lacking punchy dynamics and enough detail for my tastes. Now, I once owned an incredible amp designed by Demain Martin and Richard Marsh-Marsh Sound Design. It was a 100 watt AB. That amp was amazing on all levels. I've owned some other tube stuff as well but always found it too billowy and slow. My current CIAs with Hypex Ucd modules tick all the boxes for me. But it all comes down to personal preference. For me they work. That's it. 

 

 

 

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16 minutes ago, esldude said:

At normal listening levels the differences in distortion you think are audible would be like adding or subtracting an amount of sound that is 30 db below the audibility of human hearing, and with noise in the listening room obscuring it even then. 

 However , the fact is that these findings were verified by several DIY Audio members, both in the original and a later SC ULD mod thread , from which  you have already previously seen the measured levels at around -130dB.

 Both Nelson Pass and Douglas Self who were participants in the original thread had no problems with the findings either.

Perhaps they know a wee bit more than you do ? :D

Douglas Self was already recommending matching of LTP transistors to 1% in his books.

The spike around 7KHZ is an artefact of the PC used.

 

5v7Nv5.jpg

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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17 minutes ago, Nordkapp said:

Bel Canto ref150s, Mcintosh MC202 and 252--all sort of smooth, tonally adequate,but ultimately lacking punchy dynamics and enough detail for my tastes. Now, I once owned an incredible amp designed by Demain Martin and Richard Marsh-Marsh Sound Design. It was a 100 watt AB. That amp was amazing on all levels. I've owned some other tube stuff as well but always found it too billowy and slow. My current CIAs with Hypex Ucd modules tick all the boxes for me. But it all comes down to personal preference. For me they work. That's it. 

Just listening impressions of Bel Canto I think they go for that smooth sound.  I find it obscures detail vs some other amps, and also that the low end seems restrained even though they have good power. I do notice they have higher output impedances than some class D amps.  I wouldn't be surprised if that isn't the reason for that sound, and intentional on their part. 

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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I had a NAD M12/M22 combo that I bought kind of on a whim after seeing lots of nice reviews and it measured very well.  They also had a ton of current delivery into a low ohm load so seemed to be a good match for Martin Logans.  They were OK with my ML Montis speakers but I soon tired of the panel speakers aversion to rock music:  dreadful.

 

I listened to Sopra 2's at a dealers very listening room that is pretty heavily damped and a real microscope for gear and speakers.  I loved their overall sound and they are just a very well made and great "all rounder" of a speaker.  I was sold.  I was listening to them on a pretty decent AVM integrated (class AB) and the Pass XA 30.8.

 

Next day I was very excited to bring my NAD combo in and see how they sounded with the Sopras.  It was not good.  Dry, sterile, clinical, boring, etc. etc. etc.  Now it could've been partly to blame on the room being pretty damped, but the Sopras are pretty truthful to the electronics behind them and this just wasn't going well despite my hopes.  I was really disappointed, time to eat thousands in loss on the used market!  The minute we switched back to Class A/B amps the sound improved.  Depth, width, height, tone, everything just became more natural and enjoyable with the NAD out of the picture.  The dealer even said "that is one of the best class D amps I've heard in here, but yeah, lifeless."

 

I now have a Perla Audio Signature 50 driving the Sopra 2's and couldn't be happier.

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4 hours ago, emcdade said:

I had a NAD M12/M22 combo that I bought kind of on a whim after seeing lots of nice reviews and it measured very well.  They also had a ton of current delivery into a low ohm load so seemed to be a good match for Martin Logans.  They were OK with my ML Montis speakers but I soon tired of the panel speakers aversion to rock music:  dreadful.

 

I listened to Sopra 2's at a dealers very listening room that is pretty heavily damped and a real microscope for gear and speakers.  I loved their overall sound and they are just a very well made and great "all rounder" of a speaker.  I was sold.  I was listening to them on a pretty decent AVM integrated (class AB) and the Pass XA 30.8.

 

Next day I was very excited to bring my NAD combo in and see how they sounded with the Sopras.  It was not good.  Dry, sterile, clinical, boring, etc. etc. etc.  Now it could've been partly to blame on the room being pretty damped, but the Sopras are pretty truthful to the electronics behind them and this just wasn't going well despite my hopes.  I was really disappointed, time to eat thousands in loss on the used market!  The minute we switched back to Class A/B amps the sound improved.  Depth, width, height, tone, everything just became more natural and enjoyable with the NAD out of the picture.  The dealer even said "that is one of the best class D amps I've heard in here, but yeah, lifeless."

 

I now have a Perla Audio Signature 50 driving the Sopra 2's and couldn't be happier.

Synergy can be very elusive. 

 

 

 

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12 hours ago, emcdade said:

I had a NAD M12/M22 combo that...Next day I was very excited to bring my NAD combo in and see how they sounded with the Sopras.  It was not good.  Dry, sterile, clinical, boring, etc. etc. etc.  Now it could've been partly to blame on the room being pretty damped, but the Sopras are pretty truthful to the electronics behind them

 

For what it is worth, I have never heard a NAD combo that I liked.  IMO, it must be NAD's "house sound" and not whatever circuit topology they are using...

Hey MQA, if it is not all $voodoo$, show us the math!

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is the NuPrime ST-10 Class D??
$1595 

 

NuForce STA200 is $1299

 

 

BTW, Class D is of interest as it saves electricity (tho my electricity is carbon-safe -- not salmon safe tho); there is also the question of how much is really used by a power amp, which is likely played only a 3 hours each night...

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1 hour ago, Ralf11 said:

I've heard a lot of good things about w4s

 

Wyred 4 Sound ST-500MKII is "only" $1,500

 

Blessed by TAS too!

 

Wyred 4 Sound ST-500 mkII/ST-1000 mkII
$1499–$1999
These high-efficiency power amplifiers—delivering 250 and 500Wpc respectively—have got to be among the great bargains in audio. Although they were not accorded a formal review, PS used them to drive the Emerald Physics CS3.2 II speakers, and then for a good month auditioned them on his Quad 2805s. Throughout they performed flawlessly, delivering sound of exemplary clarity and control, perhaps fractionally on the cool side of neutral, but not excessively so and never compromising the reproduction of warmth. Pricing depends upon options (i.e., WBT binding posts, power, etc.).

 

http://www.theabsolutesound.com/articles/2017-editors-choice-power-amplifiers-1000-3000/

 

 

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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After years of class a and a/b amplification, I felt the urge to try class d.

 

There was a pair of W4S SX1000 mono blocks on Audiogon used and I bought them thinking they would be flipped after the experiment was over. That was over 2 years ago and they are still in my main system. Wonderful amps.

 

"The function of music is to release us from the tyranny of conscious thought", Sir Thomas Beecham. 

 

 

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1 hour ago, esldude said:

A level of astounding BS.  All designs have areas that have to be handled.  AB is doing the handover without distortion.  A is having low distortion with enough power and current.  All devices and classes of operation have issues.  There is currently no electronic device (tube, bipolar transistor, FET etc) that has a straight transfer curve.  

It is very easy to handle Class A issues, just make sure that your speakers aren't too needy.

 

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1 hour ago, esldude said:

A level of astounding BS.  All designs have areas that have to be handled.  AB is doing the handover without distortion.  A is having low distortion with enough power and current.  All devices and classes of operation have issues.  There is currently no electronic device (tube, bipolar transistor, FET etc) that has a straight transfer curve.  

 According to prominent Audio designer and Author Douglas Self :

Quote

Class-AB
This is not really a separate class of its own, but a combination of A and B. If an amplifier is biased
into Class-B, and then the bias further increased, it will enter AB. For outputs below a certain level
both output devices conduct, and operation is Class-A. At higher levels, one device will be turned
completely off as the other provides more current, and the distortion jumps upward at this point as
AB action begins. Each device will conduct between 50% and 100% of the time, depending on the
degree of excess bias and the output level.
Class -AB is less linear than either A or B , (my emphasis) and in my view its only legitimate use is as a fallback
mode to allow Class-A amplifiers to continue working reasonably when faced with a low-load

 

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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1 hour ago, sandyk said:

 According to prominent Audio designer and Author Douglas Self :

 

 

I don't get it, I don't think you are intending to affirm "All designs have areas that have to be handled." but you in fact did.  The area that Class A needs help is just another area (e.g. heat/power/efficiency, etc.).  "less linear" (your emphasis) is just one of those areas.  The audiophile personality you quote agrees.

 

What is a good class D design in your opinion (you know, the topic)?

Hey MQA, if it is not all $voodoo$, show us the math!

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1 hour ago, crenca said:

What is a good class D design in your opinion (you know, the topic)?

 I presume that you have seen the comparison graphs between the latest design Class D amplifiers and a good Class A or Class B design ?

 I have yet to see ANY graphs of Class D amplifiers where there isn't a tenfold increase in distortion between 5KHZ and 20KHZ in some cases, and as low as 2KHZ at some modest power levels, to 20KHZ.
Even the flagship Mola Mola Kaluga from Bruno, which starts off at around .0013% to almost 5KHZ at 10W power output, has almost a 100 fold increase in distortion from around 5KHZ to 20KHZ !

It's not too shabby though at around .004% at the low power level of 1W into 8 ohms though.
 Recent design Class A and Class B designs can however have distortion figures as low as (or better) than .0006% to 20KHZ.

 

It all comes down to whether or not you believe that very low distortion matter or not with Solid State amplifiers.
I would put it to you that the improvement that many members in other areas of the forum are hearing with modifications to various types of equipment, involves improvements in distortion figures of at least as low as the distortion in the Mola Mola Kaluga at an output power of 1W, perhaps even less.

The human ear appears to be far more sensitive to low level distortion, in the absence of higher level masking music material than most give it credit for.

 

"  The area that Class A needs help is just another area (e.g. heat/power/efficiency, etc."

 

Why should this be of concern for people who use say, 20W to 50W maximum Class A amplifiers, when Class D amplifiers used by many members at ear splitting levels into inefficient speakers STILL consume far more electricity overall ?

 Have you gone " Green"  and become a " Tree Hugger " too ? :D

 

 

 

 

 

20W Class A at 10W vs. Bel Canto Class D..jpg

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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Nord One Up is likely the very best amplifier available in the world in terms of cost/peformance.  I have heard it and it is outstanding.  It offers two options for the input stage which allows slight "tuning" of the sound as well.

 

Mola Mola Kaluga is likely the very best class d amplifier available period, and one of the best amplifiers available in the world regardless of topology.  I have never heard an amp which I could say was 'better" in any real way.  I have heard most of the heavy hitters (Solution, Audio Research ref series, VTL, Constellation, CH Precision, etc, etc).

SO/ROON/HQPe: DSD 512-Sonore opticalModuleDeluxe-Signature Rendu optical with Well Tempered Clock--DIY DSC-2 DAC with SC Pure Clock--DIY Purifi Amplifier-Focus Audio FS888 speakers-JL E 112 sub-Nordost Tyr USB, DIY EventHorizon AC cables, Iconoclast XLR & speaker cables, Synergistic Purple Fuses, Spacetime system clarifiers.  ISOAcoustics Oreas footers.                                                       

                                                                                           SONORE computer audio

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48 minutes ago, barrows said:

Nord One Up is likely the very best amplifier available in the world in terms of cost/peformance.  I have heard it and it is outstanding.  It offers two options for the input stage which allows slight "tuning" of the sound as well.

 

Mola Mola Kaluga is likely the very best class d amplifier available period, and one of the best amplifiers available in the world regardless of topology.  I have never heard an amp which I could say was 'better" in any real way.  I have heard most of the heavy hitters (Solution, Audio Research ref series, VTL, Constellation, CH Precision, etc, etc).

The Apollon Amps are very similar to the Nord and some say the internal setup is superior to the Nord. Both Nord and Apollon are now also offering amps based on the new ICE 1200 module, it would be interesting to ask them how the NCore and ICE compare.

Main listening (small home office):

Main setup: Surge protector +>Isol-8 Mini sub Axis Power Strip/Isolation>QuietPC Low Noise Server>Roon (Audiolense DRC)>Stack Audio Link II>Kii Control>Kii Three (on their own electric circuit) >GIK Room Treatments.

Secondary Path: Server with Audiolense RC>RPi4 or analog>Cayin iDAC6 MKII (tube mode) (XLR)>Kii Three .

Bedroom: SBTouch to Cambridge Soundworks Desktop Setup.
Living Room/Kitchen: Ropieee (RPi3b+ with touchscreen) + Schiit Modi3E to a pair of Morel Hogtalare. 

All absolute statements about audio are false :)

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