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

The Lounge A place to talk about almost anything but politics and religion.

John Curl's Blowtorch preamplifier part II
John Curl's Blowtorch preamplifier part II
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 2nd January 2013, 06:34 PM   #32141
gpapag is offline gpapag  Greece
diyAudio Moderator
 
gpapag's Avatar
 
Join Date: Nov 2002
Location: Athens-Greece
John Curl's Blowtorch preamplifier part II
Quote:
Originally Posted by bcarso View Post
Yes, that is a time-honored technique that I've used as well, despite the extra diode drops.

I guess I was just puzzled that you introduced (or re-introduced) the subject at this point. But as you say, the concept of a thread topic is long gone.

ThorstenL, (Kuei Yang Wang) advocated this in the long past.
There is also a dedicated thread. Pay attention to Fred Dickmann contribution (post #38)
http://www.diyaudio.com/forums/chip-...tml#post143874

Of course, apart from more balanced loading of the separated secondary windings, it all boils down to better defined return paths (hello jneutron ! )

George
__________________
["Second Law is a bitch." - SY] ["BTY my shop's large door is 14 feet wide so I can get my ego in each morning. Some evenings it can leave via the mail slot". -Ed Simon]

Last edited by gpapag; 2nd January 2013 at 06:37 PM.
  Reply With Quote
Old 2nd January 2013, 07:05 PM   #32142
john curl is offline john curl  United States
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
Thanks for the input, Ed, Brad, and others. Yes, I use the dual bridge in the CTC Blowtorch.
__________________
"Condemnation without Examination is Prejudice"
  Reply With Quote
Old 2nd January 2013, 07:05 PM   #32143
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
John Curl's Blowtorch preamplifier part II
Advantages of 2 bridges have been known for a long, long, long time.
  Reply With Quote
Old 2nd January 2013, 07:20 PM   #32144
simon7000 is offline simon7000  United States
diyAudio Member
 
Join Date: Nov 2008
Location: Oakmont PA
Quote:
Originally Posted by PMA View Post
Advantages of 2 bridges have been known for a long, long, long time.
Pavel,

Would you care to start the list of all the advantages?

ES
  Reply With Quote
Old 2nd January 2013, 07:28 PM   #32145
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
John Curl's Blowtorch preamplifier part II
Much better rejection of interference voltages, you can easily measure it and compare to center-tapped bridge. You are capable enough to do it yourself, Ed. Ground contamination of center-tapped bridge is MUCH higher.
  Reply With Quote
Old 2nd January 2013, 07:45 PM   #32146
simon7000 is offline simon7000  United States
diyAudio Member
 
Join Date: Nov 2008
Location: Oakmont PA
Quote:
Originally Posted by PMA View Post
Much better rejection of interference voltages, you can easily measure it and compare to center-tapped bridge. You are capable enough to do it yourself, Ed. Ground contamination of center-tapped bridge is MUCH higher.
You mean like this?
Attached Images
File Type: jpg AC only W noise source.JPG (587.1 KB, 193 views)
File Type: jpg 4700 only no CG.JPG (602.5 KB, 186 views)
File Type: jpg 2 Caps.JPG (658.0 KB, 159 views)
  Reply With Quote
Old 2nd January 2013, 08:24 PM   #32147
Telstar is offline Telstar  Italy
diyAudio Member
 
Join Date: Dec 2007
Location: Italy
Quote:
Originally Posted by RNMarsh View Post
yes. My sediments, exactly :-)
Are you a stone, or you did mean sentiments, Ryan?
__________________
"The total harmonic distortion is not a measure of the degree of distastefulness to the listener and it is recommended that its use should be discontinued." D. Masa, 1938
  Reply With Quote
Old 2nd January 2013, 08:26 PM   #32148
jcx is offline jcx  United States
diyAudio Member
 
Join Date: Feb 2003
Location: ..
being able to use the better performance positive linear regulators for both polarities is a handy split sec/dual bridge feature

but in a preamp avoiding most of the single bridge-CT common impedance noise isn't that hard with intelligent layout, routing, choice of gnd points - in power amps the currents are a little large for doing it right with just pcb trace - but still can be largely attenuated compared to naive implementations

but treating it as a pro level audio amp design secret when the issue is shown in Self, Cordell books is a little behind the times - either nih syndrome or once again propping up a strawman version of what "conventional enigeering" knows, even modestly well read interested audio amp designers should have seen

Last edited by jcx; 2nd January 2013 at 08:38 PM.
  Reply With Quote
Old 2nd January 2013, 08:40 PM   #32149
john curl is offline john curl  United States
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
As we know:
1. It is impossible
2. It is possible but not important
3. We invented it. '-)
__________________
"Condemnation without Examination is Prejudice"
  Reply With Quote
Old 2nd January 2013, 08:47 PM   #32150
jcx is offline jcx  United States
diyAudio Member
 
Join Date: Feb 2003
Location: ..
who cares about ancient history, exact path to best practice, it all has to come form somewhere - and some local "audio" designers seem to be reluctant to credit EE as having more sophistication, many sub fields, think they don't have to look in any other specialty for design principles, insights

but now its in audio power amplifier design "textbooks", hard to deny that == "what conventional (audio) engineering knows"
  Reply With Quote

Reply


John Curl's Blowtorch preamplifier part IIHide 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


New To Site? Need Help?

All times are GMT. The time now is 05:04 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki