class XD - Doug Self is at it again - diyAudio
Go Back   Home > Forums > Source & Line > Analog Line Level

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

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 7th December 2006, 12:23 PM   #1
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Great City of Turnhout, Belgium
Blog Entries: 7
Default class XD - Doug Self is at it again

Hi,

Anybody seem this, any opinions? Touted as the next breakthrough in analogue amps, well, don't know about that.

http://www.cambridgeaudio.com/assets...r8-2-06web.pdf

Certainly the technique is far from new. They refer to a UK patent, anybody can get a hold of that?

Jan Didden
__________________
I won't make the tactical error to try to dislodge with rational arguments a conviction that is beyond reason - Daniel Dennett
Check out Linear Audio Vol 7!
  Reply With Quote
Old 7th December 2006, 12:27 PM   #2
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Take a look at John Broskie's writeup at www.tubecad.com .
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 7th December 2006, 12:35 PM   #3
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Great City of Turnhout, Belgium
Blog Entries: 7
Quote:
Originally posted by SY
Take a look at John Broskie's writeup at www.tubecad.com .

Yes I have seen that. The idea comes and goes in many places, that is why I would love to read the patent application. I am always fascinated by literary attemps to present as a 'breakthrough' things that are already gathering dust...

Jan Didden
__________________
I won't make the tactical error to try to dislodge with rational arguments a conviction that is beyond reason - Daniel Dennett
Check out Linear Audio Vol 7!
  Reply With Quote
Old 8th December 2006, 09:59 AM   #4
AndrewT is online now AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
I cannot fault the white paper.

There are similarities to the ClassA conversion used to linearise ClassAB push pull opamps.
Which came first?

Can we reduce dissipation in the converted opamp this way?

How does the XDpp work?
What is inside the -a stage that varies the CCS?
__________________
regards Andrew T.
  Reply With Quote
Old 10th December 2006, 02:40 PM   #5
diyAudio Member
 
Join Date: Sep 2003
Location: n
This may link to the patent...

http://v3.espacenet.com/origdoc?DB=E...&QPN=GB2424137

Paul
  Reply With Quote
Old 10th December 2006, 03:19 PM   #6
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Quote:
Originally posted by AndrewT

I cannot fault the white paper.
Hmmm........

Well its a white paper so it doesn't have to be accurate.

IMO it sets out to deliberately mislead the reader into
thinking it is applicable to EF output states, it is not,
though they haven't bothered swapping the types
of the output devices, a PNP is shown as NPN.
(figs 5, 6 and 7)

It only works well with CFP outputs.

/sreten.
  Reply With Quote
Old 10th December 2006, 03:28 PM   #7
diyAudio Member
 
Jan Dupont's Avatar
 
Join Date: Apr 2003
Location: Copenhagen, Denmark
Send a message via MSN to Jan Dupont
Have a look at this thread;
Class XD....

__________________
Free Schematic and Service Manual downloads www.audio-circuit.dk, Company: www.dupont-audio.com, Joint venture: www.DupontMantra.com
  Reply With Quote

Reply


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
Doug Self Circuits steevo Solid State 29 12th November 2013 04:44 PM
Doug Self editing errors pooge Solid State 34 11th August 2007 09:43 PM
blameless amp and doug self streetera Solid State 17 16th July 2007 10:06 PM
My name is Doug and I'm an Audiophile Doug Reid Introductions 2 19th April 2003 07:22 PM


New To Site? Need Help?

All times are GMT. The time now is 10:15 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2