Class D power amplifiers

Are class D amps finally ready for prime time for audioholics, even audiophiles, if not why not?

  • Yes

    Votes: 14 56.0%
  • Yes, but probably not audiophiles

    Votes: 1 4.0%
  • May be, it depends..

    Votes: 5 20.0%
  • Don't know

    Votes: 3 12.0%
  • No, they are not ready for prime time because..

    Votes: 1 4.0%
  • Yes, but only those with good specs confirmed by bench tests

    Votes: 1 4.0%

  • Total voters
    25
lovinthehd

lovinthehd

Audioholic Jedi
ParaSound amplifiers are assembled in Taipei, Taiwan the factory is very experienced and builds for many other audio brands including Harman/Kardon, SpeakerCraft, Outlaw Audio.....

Just my $0.02... ;)
Do you know if they (Parasound) ever had US manufacturing?
 
K

kaseaman

Junior Audioholic
Figured I would chime in here given I switched over to class D last year (at least for my front 3 channels for the time being). Now although the amps I own are Pascal based (D Sonic amplifiers) so they dont have as low distortion levels as the purifi or Hypex, I do have to say at this point, having lived with this amp for a year, I absolutely love it. Runs cool, has a lower noise floor than any other external amp I have owned, and has gobs of power to boot. If anyone is in the market for a class D amplifier with a solidly built case and great customer service I definitely suggest looking into D-Sonic. And pretty soon they will be driving what I believe to be fairly high end speakers (Focal Sopra No 3). I will for sure report back once I actually get them delivered and running elite the D Sonic
 
W

warnerwh

Full Audioholic
I would say some Class D amps are ready for prime time but others are not. I'm still seeing Class D amps having problems driving a reactive load and keeping the frequency response flat. I really don't care about the efficiency or weight but am curious. The Buckeye amps look tempting but only to see for myself. I'd likely sell it after a couple of weeks though.
 
A

Am_P

Audioholic
Every Class D I've heard to this day sounded like ass (tried it more than a few times, got rid of it each time). Thank God, the likes of Yamaha, Parasound, Luxman, etc or a few out there are still sticking with AB, at the least.

Weight? Not a concern (not some lazy fart who hits the gym once in 20 years). Power savings? I've got solar panels. Heat? Comes in very handy during my six months of winter I'll stick with my class A and class AB. I guess I must be an "audiophile"!!
 
P

PENG

Audioholic Slumlord
I would say some Class D amps are ready for prime time but others are not. I'm still seeing Class D amps having problems driving a reactive load and keeping the frequency response flat.
Thank you, excellent point about ....some are ready......but others are not... I was surprised to find out I could add another choice to the poll.:)
 
Pogre

Pogre

Audioholic Overlord
Thank you, excellent point about ....some are ready......but others are not... I was surprised to find out I could add another choice to the poll.:)
I think you sufficiently covered it with "maybe, it depends..." (which is what I chose).
 
J

Jeepers

Full Audioholic
Every Class D I've heard to this day sounded like ass (tried it more than a few times, got rid of it each time). Thank God, the likes of Yamaha, Parasound, Luxman, etc or a few out there are still sticking with AB, at the least.

Weight? Not a concern (not some lazy fart who hits the gym once in 20 years). Power savings? I've got solar panels. Heat? Comes in very handy during my six months of winter I'll stick with my class A and class AB. I guess I must be an "audiophile"!!
I am sorry to read you don't have a musical ass.

I used to have Yamaha amps, the last one being the DSP-Z11 which sounded very nice to me.
In 2011 I moved to class D amps and since several years I have a Lyngdorf DPA-1 (pre-amp) and a Millennium MkIV. To me they sound better than the Yamaha amps I used to have but maybe my ears are like your ass.
 
P

PENG

Audioholic Slumlord
I am sorry to read you don't have a musical ass.

I used to have Yamaha amps, the last one being the DSP-Z11 which sounded very nice to me.
In 2011 I moved to class D amps and since several years I have a Lyngdorf DPA-1 (pre-amp) and a Millennium MkIV. To me they sound better than the Yamaha amps I used to have but maybe my ears are like your ass.
You picked a good one to compare, the DSP-Z11, if it is the twin of the RX-Z11, has the best preamp measurements on Gene's bench, and the amp section also measured well, comparable to those Hypex amps up to say 120 W into 8 ohms. That's quite amazing for AVR amps vs some of today's best separate power amps, class D or not.
 
P

PENG

Audioholic Slumlord
I think you could be right about the signal path in the Anthem. And that’s pretty wild about the 4400 vs 8801 haha.
Now I know I got the impression that Anthem would route all signals through the DSP so analog inputs would have to go through the ADC, from their FAQ. I might have misunderstood them though as their answers seemed convoluted and was all over the place. You will see what I mean if you do a key word search on "analog" over there.

Yes the 8801, while still quiet enough, it does seem wild that it was audibly nosier than the 4400 even with only one input connected versus the octopuses laden 4400. On the other hand, the 4400 has virtually the same signal chain circuitry and parts as the newer 3600 and 4500 so it possible has comparable SINAD from the pre out and that would be 96 to 100 dB, vs the AV8805's 92 dB, and the AV8801 likely could do more than 90 dB at 2V, that's 4 V with volume at "0" and I was comparing the two at +18. So I guess it could have been anticipated.
 
S

Sam780

Audiophyte
Very interesting. As a new member here, I started looking at various threads and stumbled into this one. Since I have been out of this hobby (to me it's a hobby) for more than 20+ years, I never really heard about Class D amps. Although my current main amp is a Mc2600, I am always interested in what for me might be new technology. Naturally I then searched for reading material and found 2 articles, by Eric Gaalaas and David Mellor, that although written in 2006 were very informative. As an amateur radio operator who has to block a lot of RFI coming into the station I am wondering if anyone here can comment on potential RFI from the switching components in Class D amps. Appreciate any and all information.
 
A

Am_P

Audioholic
I am sorry to read you don't have a musical ass.

I used to have Yamaha amps, the last one being the DSP-Z11 which sounded very nice to me.
In 2011 I moved to class D amps and since several years I have a Lyngdorf DPA-1 (pre-amp) and a Millennium MkIV. To me they sound better than the Yamaha amps I used to have but maybe my ears are like your ass.
Right right...profit margins for those D manufacturers must be getting better..getting those Chinese boards en masse, slapping them on and selling it to the D lovers (lower shipping costs too, i suppose)....But, but, it sounds like ass?? No, they're covered, they'll put a dummy 8 ohm or 4 ohm load and hand you a measurement (never mind that your speaker is a complex impedance). As soon as the class D lover saw that measurement, it should start sounding real good to him.

Eitherway, plug Lyngdork or whatever class D in the ass or ear, wherever it sounds best.....
 
Swerd

Swerd

Audioholic Warlord
Very interesting. As a new member here, I started looking at various threads and stumbled into this one. Since I have been out of this hobby (to me it's a hobby) for more than 20+ years, I never really heard about Class D amps. Although my current main amp is a Mc2600, I am always interested in what for me might be new technology. Naturally I then searched for reading material and found 2 articles, by Eric Gaalaas and David Mellor, that although written in 2006 were very informative. As an amateur radio operator who has to block a lot of RFI coming into the station I am wondering if anyone here can comment on potential RFI from the switching components in Class D amps. Appreciate any and all information.
I don't have a specific answer for your RFI question, but I can offer you more reading material.

The best explanation and most lengthy seems to be the first link below which was presented by Bruno Putzeys (founder of Hypex) at the 2007 AES meeting as a "Class D master class". It was a talk with a lot of slides. It explains class D principles in detail, and also the different basic topologies, the hysteresis modulator, and the phase shift controlled oscillator. It also presents the benefits and limitations of both approaches, and tells readers what to expect from both approaches. (Most of this was above my paygrade. I searched this for RFI but found nothing. A search for EMI found 27 mentions.)
https://www.hypex.nl/img/upload/doc/an_wp/WP_AES124BP_A_universal_grammar of class_D.pdf

The next three links are shorter papers, 5 to 8 pages long, that were mostly easier to understand:
UcD principle and comparison to hysteresis modulator is also explained in:
https://www.hypex.nl/img/upload/doc/an_wp/WP_AES118BP_Simple_self-oscillating_class D_amplifier.pdf

NCore improvement over UcD in:
https://www.hypex.nl/img/upload/doc/an_wp/WP_Globally_modulated_self-oscillating_amplifier.pdf

And also in:
https://www.hypex.nl/img/upload/doc/an_wp/WP_Ncore_Technology.pdf

You might find useful info in the Hypex web site:
 
Last edited:
P

PENG

Audioholic Slumlord
Very interesting. As a new member here, I started looking at various threads and stumbled into this one. Since I have been out of this hobby (to me it's a hobby) for more than 20+ years, I never really heard about Class D amps. Although my current main amp is a Mc2600, I am always interested in what for me might be new technology. Naturally I then searched for reading material and found 2 articles, by Eric Gaalaas and David Mellor, that although written in 2006 were very informative. As an amateur radio operator who has to block a lot of RFI coming into the station I am wondering if anyone here can comment on potential RFI from the switching components in Class D amps. Appreciate any and all information.
The switching frequencies are in the order of hundreds of kHz. There is no issues of that affecting the audios, so are you concerned about its effect on nearby devices that operates on that range such as AM radio?
 
T

tparm

Audioholic
Based on Gene's results with the analog path for the A6A I'd like to demo that combined with a D90se and NAD C298 powering the LR channels. :)
 
P

PENG

Audioholic Slumlord
Based on Gene's results with the analog path for the A6A I'd like to demo that combined with a D90se and NAD C298 powering the LR channels. :)
What results? Link please.. thank you
 
S

Sam780

Audiophyte
I don't have a specific answer for your RFI question, but I can offer you more reading material.

The best explanation and most lengthy seems to be the first link below which was presented by Bruno Putzeys (founder of Hypex) at the 2007 AES meeting as a "Class D master class". It was a talk with a lot of slides. It explains class D principles in detail, and also the different basic topologies, the hysteresis modulator, and the phase shift controlled oscillator. It also presents the benefits and limitations of both approaches, and tells readers what to expect from both approaches. (Most of this was above my paygrade. I searched this for RFI but found nothing. A search for EMI found 27 mentions.)
https://www.hypex.nl/img/upload/doc/an_wp/WP_AES124BP_A_universal_grammar of class_D.pdf

The next three links are shorter papers, 5 to 8 pages long, that were mostly easier to understand:
UcD principle and comparison to hysteresis modulator is also explained in:
https://www.hypex.nl/img/upload/doc/an_wp/WP_AES118BP_Simple_self-oscillating_class D_amplifier.pdf

NCore improvement over UcD in:
https://www.hypex.nl/img/upload/doc/an_wp/WP_Globally_modulated_self-oscillating_amplifier.pdf

And also in:
https://www.hypex.nl/img/upload/doc/an_wp/WP_Ncore_Technology.pdf

You might find useful info in the Hypex web site:
Thank you for the links. The article/slides by Bruno Putzeys of Hypex Electronics were very descriptive and informative.
 
T

tparm

Audioholic
What results? Link please.. thank you
There seems to be some multi-channel issues but otherwise the results are pretty nice. Video coming tomorrow from what I understand.

 
S

Sam780

Audiophyte
The switching frequencies are in the order of hundreds of kHz. There is no issues of that affecting the audios, so are you concerned about its effect on nearby devices that operates on that range such as AM radio?
Yes, it is in the radio domain from 1.8Mhz through 18Mhz. You would be amazed at the amount of RFI that is being thrown off by all the microprocessors and LED lights that are now found in various appliances throughout the home. and in the neighborhood.
 
J

Jeepers

Full Audioholic
You picked a good one to compare, the DSP-Z11, if it is the twin of the RX-Z11, has the best preamp measurements on Gene's bench, and the amp section also measured well, comparable to those Hypex amps up to say 120 W into 8 ohms. That's quite amazing for AVR amps vs some of today's best separate power amps, class D or not.
The RX-Z11 was sold in the US and other places as a receiver; in Europe it was sold as an amplifier with model name DSP-Z11.
 
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