Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Class D Switching Power Amplifiers and Power D/A conversion

CLASS AB Amplifier Vs CLASS D Amplifier
CLASS AB Amplifier Vs CLASS D Amplifier
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 28th August 2011, 05:47 PM   #21
kct is offline kct  Canada
diyAudio Member
 
kct's Avatar
 
Join Date: Dec 2006
Location: KW, Ontario
CLASS AB Amplifier Vs CLASS D Amplifier
Quote:
Originally Posted by Saturnus View Post
To expand on what I said earlier. It's true that some class D amps aren't properly designed and therefore aren't terribly good but from person experience then a well built class D far exceeds the sound quality achievable by class AB or class A amps regardless of price.

So for a modern amp you so only consider class D if you care about sound quality at all, class AB is basically junk only suited for the scrapheap.
Saturnus,

seriously, with all due respect when talking about sound quality, but please I may have missed it, at which point did Class D Amps exceed the performance specs of a decent Class AB other than efficiency and perhaps power ? What is the general magnitude of THD of a Class D at lets say 20kHz at rated power ? Can you find a spec on that to backup your claim that Class D is far exceeds the sound quality of a Class AB ?

Let me guess, either you are almost deaf or you have a great selection of MP3's you use to judge about amplifier sound quality.
  Reply With Quote
Old 28th August 2011, 06:57 PM   #22
Saturnus is offline Saturnus  Denmark
diyAudio Member
 
Saturnus's Avatar
 
Join Date: Jun 2005
Location: Copenhagen, Denmark
Quote:
Originally Posted by kct View Post
Let me guess, either you are almost deaf or you have a great selection of MP3's you use to judge about amplifier sound quality.
And let me guess that you have never heard a live performance in your life, and therefore have no idea how any instrument is actually supposed to sound.
  Reply With Quote
Old 28th August 2011, 07:39 PM   #23
kct is offline kct  Canada
diyAudio Member
 
kct's Avatar
 
Join Date: Dec 2006
Location: KW, Ontario
CLASS AB Amplifier Vs CLASS D Amplifier
Quote:
Originally Posted by Saturnus View Post
And let me guess that you have never heard a live performance in your life, and therefore have no idea how any instrument is actually supposed to sound.
Actually, yes, I was recently and it sounded horrible with all the echos, feedbacks and audience noise. But if this is how this should sound like, then I missing out a lot and there must be something seriously wrong with my CD's.

Did you manage to find a Class D THD spec. far exceeding that of a decent Class AB amp ?

Cheers
  Reply With Quote
Old 28th August 2011, 07:49 PM   #24
kristleifur is offline kristleifur  Iceland
diyAudio Member
 
Join Date: Apr 2006
Location: Reykjavík
Quote:
Originally Posted by kct View Post
Did you manage to find a Class D THD spec. far exceeding that of a decent Class AB amp ?
0.005-0.008% THD+N is in the realm of 'low enough' in my book. THD hardly measures sound quality anyway ...

Otherwise, how does this look to you?: Ncore Announcement

And anyway - there are exquisite sounding Class D amplifiers out there, and that's that!
  Reply With Quote
Old 28th August 2011, 11:13 PM   #25
Saturnus is offline Saturnus  Denmark
diyAudio Member
 
Saturnus's Avatar
 
Join Date: Jun 2005
Location: Copenhagen, Denmark
Quote:
Originally Posted by kristleifur View Post
0.005-0.008% THD+N is in the realm of 'low enough' in my book. THD hardly measures sound quality anyway ...
My old, now scraped Son of Zen amp had terrible THD+N rating as do most tube amps, at least those I've had, so I complete agree. No one that has an interest in music cares about distortion figures but how the distortion sounds. In essence all instruments distorts sound anyways, otherwise they'd just be sine wave generators. And our ears depend on distortion to in order to localize sound. Speakers also distort far more than a typical amp so it hardly matter much an amp distorts, it's more a question of how it distorts.
  Reply With Quote
Old 29th August 2011, 12:35 AM   #26
TheDealer is offline TheDealer  Germany
diyAudio Member
 
Join Date: Apr 2008
Quote:
Originally Posted by Saturnus View Post
, it's more a question of how it distorts.
I was told by many experts that a tube amp distorts earlier but in a harmonic way while a Transistor designed amp in Class A/B principle distorts later but it leads then into a terrible result ...

In a very confident and a trustfully german high end magazine I noticed very often that the testers prefer and handle tube amps like their own childs.
We should not forget that the margins of a class A/B transistor amp are much more than of a tube amp (preconditioned it is hand made in europe). In automation way Transistor amps are much more cheaper to produce.

I can imagine that these "magic" in sound is delivered best by tube amps but I am honestly not the friend of them: not easy to handle, higher current consumption for some watts, bass could be a bit sponge. I think a Tripath
is the way to go. I am very pleased with some of them.
  Reply With Quote
Old 29th August 2011, 03:02 AM   #27
kct is offline kct  Canada
diyAudio Member
 
kct's Avatar
 
Join Date: Dec 2006
Location: KW, Ontario
CLASS AB Amplifier Vs CLASS D Amplifier
Quote:
Originally Posted by kristleifur View Post
0.005-0.008% THD+N is in the realm of 'low enough' in my book. THD hardly measures sound quality anyway ...

Otherwise, how does this look to you?: Ncore Announcement

And anyway - there are exquisite sounding Class D amplifiers out there, and that's that!
kristleifur,

interesting paper you had referred to, I have to admit, I was not aware of that, the specs given in this paper, if true, are getting close to if not surpassing Class AB performance. Seems it is time for me to take Class D for a serious test drive...
  Reply With Quote
Old 30th August 2011, 04:12 AM   #28
MOER is offline MOER  United States
diyAudio Member
 
Join Date: Aug 2003
Location: NEWBURY PARK CA
Default Class D vs Class A and B

I design and build both types of amplifiers. Class D in terms of efficiency cannot be beat. Raw specs the class B route is the best. I use as my reference my highly modified McIntosh MI350 mono blocks.

No amplifier I have designed can approach the performance of these McIntosh amplifiers. I do direct double blind A-B listening tests and the Macs always come out on top. Yes they are huge at 125 pounds each, 19" rack mount and they suck huge amounts of power from the wall socket.

For our mobile amplifiers we stand by class D. Class B in a car cannot compete. The issue of limited bandwidth is not an issue in the car. Our class Ds are flat to 35KHz with 2,4, and 8 ohm speakers.

Steve Mantz

Zed Audio Corp.
  Reply With Quote
Old 31st August 2011, 01:29 AM   #29
ljm_ljm is offline ljm_ljm  China
diyAudio Member
 
Join Date: Sep 2006
The biggest advantage of Class D power, high efficiency.

So the best place for high power, rather than for. Loudspeakers, because they require little power, but it takes a very small distortion.

If a simple choice, I recommend that you use LM4766T
  Reply With Quote
Old 31st December 2011, 06:34 PM   #30
Ringo4422 is offline Ringo4422
diyAudio Member
 
Join Date: Dec 2011
Default Amused by this Blog

I am totally amused by this entire blog. High Fidelity by definition means very close to the original program material. Class D amplifiers cannot and will never be able to compete with a Class A or AB amplifier with regard to sound fidelity, period. There are many who dispute this, but then again, most people cannot differentiate between good sound and mediocre sound quality anyway. It takes a "real" musical artist or someone close to an audiophile to actually understand the difference they are hearing. There are many more details to specifications than the general S/N ratio or THD. How about Square Wave Tilt, or Transient Intermodulation Distortion? What about the artifacts generated by class D amplifiers that don't even exist with a Class A or AB amplifier. These do exist and can be heard.

The big difference here is music content. There is basically no quality recordings created today, most being distorted computer generated sounds and of course my favorite, autotune. High fidelity is not needed for this program source because the source itself is far from high fidelity anyway. Therefore, class D audio is fine for this.

So, if you want it to sound really "nice" in your car or home, go with a good class AB amplifier (one with transistor outputs, not amplifier ICs). If you want to show off how really loud your equipment is so the entire neighborhood knows you are around, class D is the only way to go. But if you can't even tell the difference, go with what you like and subscribe to 16 kb/s Serius-XM satellite radio streams as well.

Signed,
A very seasoned & experienced analog /digital audio electronics design engineer.
  Reply With Quote

Reply


CLASS AB Amplifier Vs CLASS D AmplifierHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Questions about how to decrease the PASS A-40 amplifier into a class AB amplifier. novtango Pass Labs 4 14th February 2018 05:11 PM
Class AB Amplifier - New to the analog world ea6b607 Solid State 40 28th March 2011 07:28 PM
Pi filter for Class AB amplifier, feedback please pjpoes Solid State 4 21st March 2007 09:27 AM
A good Brazilian Amplifier, class A switching to AB in hi power destroyer X Solid State 65 24th March 2005 08:12 PM
Class AB Amplifier USFishin Solid State 1 28th March 2004 03:25 PM


New To Site? Need Help?

All times are GMT. The time now is 06:34 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki