ClassA, how does it work? - diyAudio
Go Back   Home > Forums > Amplifiers > Class D
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Class D Switching Power Amplifiers and Power D/A conversion

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
Thread Tools Search this Thread
Old 10th March 2008, 06:40 AM   #1
diyAudio Moderator Emeritus
lumanauw's Avatar
Join Date: Oct 2002
Location: Bandung
Send a message via Yahoo to lumanauw
Default ClassA, how does it work?

How does it work? Why the example use only +/-14V, and the selfoscilating frequency only 100khz?

Won't work for +/-50V at 400khz?
  Reply With Quote
Old 10th March 2008, 12:49 PM   #2
TheMG is offline TheMG  Canada
diyAudio Member
Join Date: Jan 2008
All it is is a Class D amplifier driving a Class A amplifier output stage. Doesn't make any practical sense, since you're losing nearly all the benefits of the high efficiency of Class D and end up with a VERY inefficient amplifier.
  Reply With Quote
Old 10th March 2008, 01:37 PM   #3
fredos is offline fredos  Canada
diyAudio Member
Join Date: Mar 2005
Location: Quebec
I think that MG didnt read carefully...The class d just lift the low voltage psu of the class a amplifier to provide high voltage output swing. Since it lift the power supply form the middle point, no power supply perturbation will affect the class A stage. Funny that this is very close to the labgruppen patent...
  Reply With Quote
Old 10th March 2008, 03:56 PM   #4
Pafi is offline Pafi  Hungary
diyAudio Member
Join Date: May 2004
Location: Budapest
I'm almost sure I have seen the first figure (I mean: an equivalent schematic) earlier than 2006. I don't think this is an invention. It's sooo trivial!
  Reply With Quote
Old 10th March 2008, 04:39 PM   #5
diyAudio Member
Ouroboros's Avatar
Join Date: Dec 2003
Location: Nottingham UK
Peter Walker back in the 1970s spoke about the possibility of a Quad405-like current dumping arcitecture but using a class-D amp as the beefy 'current dumping' source.
  Reply With Quote
Old 10th March 2008, 08:33 PM   #6
Tim__x is offline Tim__x  Canada
diyAudio Member
Join Date: Jun 2004
Location: Edmonton area, Alberta
Current dumping is a different concept.
This is class-H/tracking supplies, it's not all that unique, it's not new, and it's not that great of an idea.
  Reply With Quote
Old 11th March 2008, 10:33 AM   #7
diyAudio Moderator Emeritus
lumanauw's Avatar
Join Date: Oct 2002
Location: Bandung
Send a message via Yahoo to lumanauw
I can only guess, this schottky+1000uF is a clever way to make use of the residual of IRAUDAMP system. IRAUDAMP use pre-filter feedback point.
Fredos, I think it is a bit different than labgruppen patent, since the sources of final mosfets are only connected to schottky+cap bank floating supply. I also don't know how can we adjust the margin (VDS) of this scheme. Maybe adjusting the cap value?
  Reply With Quote


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
3-5 watts classA amp adason Solid State 21 16th December 2009 07:15 PM
Bootstrapped ClassA - ? Bigun Solid State 24 28th August 2009 02:20 PM
SE ClassA with low dissipation @ idle - is this it ? Bernhard Pass Labs 39 2nd December 2003 11:24 AM

New To Site? Need Help?

All times are GMT. The time now is 03:19 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2