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

My class D amp
My class D amp
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 5th July 2013, 07:16 AM   #391
manojtm is offline manojtm  India
diyAudio Member
 
manojtm's Avatar
 
Join Date: Aug 2008
Location: KERALA
Quote:
Pre filter feedback selfosc = Class D done WRONG! (BAD design)
Post filter feedback self osc = Class D done RIGHT! (Good design)
Hi Tekko,

Its only a marketing Technics. No one is 100% perfect design.

My AUD600 = crystal clear sound, no noise,and better power output.

Regards
MANOJ
  Reply With Quote
Old 5th July 2013, 07:40 AM   #392
Tekko is offline Tekko
Banned
 
Join Date: Jan 2005
And its limited to one single load impedance without changing the output filter = bad!
  Reply With Quote
Old 5th July 2013, 08:54 AM   #393
syaelend is offline syaelend
diyAudio Member
 
Join Date: Feb 2011
Quote:
Originally Posted by manojtm View Post
Hi Tekko,

Its only a marketing Technics. No one is 100% perfect design.

My AUD600 = crystal clear sound, no noise,and better power output.

Regards
MANOJ
Hi Mr. Manoj,
On your AUD600 ver 3.0 you use PIC629, is it a micro controller ic? what does it used?
Regards

Syaelend
  Reply With Quote
Old 5th July 2013, 08:55 AM   #394
Tekko is offline Tekko
Banned
 
Join Date: Jan 2005
I guess overcurrent sensing and dc on output for speaker protection.
  Reply With Quote
Old 5th July 2013, 09:06 AM   #395
don2007ksa is offline don2007ksa  Philippines
diyAudio Member
 
Join Date: Mar 2008
Location: ksa
Hi Tekko,post filter feedback run's at hotter output coil inductor,please share a schematic (UCD POST FILTER F.B.)to give it a try,thank's.
  Reply With Quote
Old 5th July 2013, 09:16 AM   #396
Tekko is offline Tekko
Banned
 
Join Date: Jan 2005
Heating of the inductor has nothing to do with topology, but has to do with the inductor itself like core material, heating is a sign that the material is not ideal.

My UcD class d project does not heat the inductors at all when o use the one from coilcraft for the zetex class d.

I'd share my schematic but considering how expensive the MAX913/LT1016/AD8561 comparator is, its not really practical and i have not been able to find suitable readily available replacements.
  Reply With Quote
Old 5th July 2013, 09:57 AM   #397
manojtm is offline manojtm  India
diyAudio Member
 
manojtm's Avatar
 
Join Date: Aug 2008
Location: KERALA
Quote:
On your AUD600 ver 3.0 you use PIC629, is it a micro controller ic? what does it used?
Hi Syaelend,

AUD600 Ver1.0,1.1,3.0 & 3.0.1 donot using PIC629(PIC microcontroller)

Regards
MANOJ
  Reply With Quote
Old 5th July 2013, 10:01 AM   #398
manojtm is offline manojtm  India
diyAudio Member
 
manojtm's Avatar
 
Join Date: Aug 2008
Location: KERALA
Quote:
And its limited to one single load impedance without changing the output filter = bad!
Hi Tekko,

You mean Post filter feedback will change fsw when you change load impedance or fsw constant and only effect NFB ( Audio freq. stabilization ) and THD

Regards
MANOJ
  Reply With Quote
Old 5th July 2013, 10:08 AM   #399
ChingTan is offline ChingTan  Philippines
diyAudio Member
 
ChingTan's Avatar
 
Join Date: Jan 2011
Location: butuan city ph.
Send a message via Yahoo to ChingTan
hi manojtm can you post where i can get your official aud600 3 is it free for diy?
  Reply With Quote
Old 5th July 2013, 10:31 AM   #400
Tekko is offline Tekko
Banned
 
Join Date: Jan 2005
Quote:
Originally Posted by manojtm View Post
Hi Tekko,

You mean Post filter feedback will change fsw when you change load impedance or fsw constant and only effect NFB ( Audio freq. stabilization ) and THD

Regards
MANOJ
I switched between open circuit and 0.8 ohm load on my ucd class d in BTL mode yesterday and the switching freq dident even flinge, it stayed on ~360kHz and did not move.

The problem with pre filter feedback self osc as several have outlined is that if the amp is made for 4 ohms, then at 8 ohms the freq response will increase as a spike at higher frequencies, whilst it may not be audible to most its still unacceptable as it means the amp is unstable.

Likewise a amp made for 8 ohms will start rolling off at early as 5kHz with a 4 ohm load.

While on UcD (post filter fb selfosc) the frq response barely changes at all from 0.5 ohms(some car subwoofers) to unloaded, it never starts spiking/peaking at higher freq like pre filter fb does.
  Reply With Quote

Reply


My class D ampHide 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
TBJ's Class D - a discrete class D amp that anyone can build! (Work-In-Progress) tbj Class D 11 18th January 2017 07:49 PM
Leaving class A how to make this amp leave class A to AB when volume is increased? rhythmsandy Solid State 3 14th June 2016 01:16 AM
Contest: Linear Power Amp in a mint tin (class Aa, class AB, or class B) danielwritesbac Chip Amps 206 19th January 2013 08:52 PM
does class A amp feel more powerful with same ratings compared to class AB? rhythmsandy Solid State 7 10th December 2012 05:21 PM
Can a Class AB PP amp be said to be operating in Class A at low signal levels? ray_moth Tubes / Valves 19 23rd January 2009 07:52 PM


New To Site? Need Help?

All times are GMT. The time now is 03:50 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