John Curl's Blowtorch preamplifier part II - Page 2709 - diyAudio
Go Back   Home > Forums > Member Areas > The Lounge

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

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 30th August 2012, 04:11 PM   #27081
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Quote:
Originally Posted by john curl View Post
Richard is right. Both Charles Hansen and I use very low power supply rejection topologies. We have to make up for this by designing custom, super low noise/distortion power supply buffers to take the nominal DC to a really low noise DC.
This is a strange thing coming from someone who cherishes complimentary symmetry and balanced design. What do you gain with poor PSRR circuits?
__________________
"This logos holds always but humans always prove unable to understand it, both before hearing it and when they have first heard it."
  Reply With Quote
Old 30th August 2012, 04:26 PM   #27082
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
I gain nothing but the optimum topology for the job at hand.
  Reply With Quote
Old 30th August 2012, 04:34 PM   #27083
morinix is offline morinix  United States
diyAudio Member
 
Join Date: Jun 2006
I heard the band War on a DD vinyl once. It was like taking a vitamin rather than eating a meal.

OOPS Sorry it was Tower Of Power Sheffield Lab. Still though
__________________
Robert
Lounge Audio

Last edited by morinix; 30th August 2012 at 04:43 PM.
  Reply With Quote
Old 30th August 2012, 05:11 PM   #27084
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
Well, that was just one record, and not necessarily their best offering. I have virtually 'fallen in love' with an unknown singer (to me) from listening on a set of quad electrostatics and Electrocompaniet electronics in Oslo, Norway, of a Sheffield direct disc record. That is HOW I could easily verify that these guys from Electro. were on to something.
  Reply With Quote
Old 30th August 2012, 05:16 PM   #27085
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Actually, for that genre, it's a pretty good recording.
__________________
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 30th August 2012, 09:43 PM   #27086
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Quote:
Originally Posted by john curl View Post
I gain nothing but the optimum topology for the job at hand.

That output stage is a throwback to things like Futterman OTL.

Here's one, the hot chassis is an added feature. Does anyone know if this predates Kaneda?
Attached Images
File Type: gif RCAOTL.gif (86.0 KB, 230 views)
__________________
"This logos holds always but humans always prove unable to understand it, both before hearing it and when they have first heard it."

Last edited by scott wurcer; 30th August 2012 at 09:47 PM.
  Reply With Quote
Old 30th August 2012, 10:06 PM   #27087
bcarso is offline bcarso  United States
diyAudio Member
 
Join Date: May 2005
Location: Canoga Park, California
Quote:
Originally Posted by scott wurcer View Post

Here's one, the hot chassis is an added feature.
  Reply With Quote
Old 30th August 2012, 11:21 PM   #27088
diyAudio Member
 
Wavebourn's Avatar
 
Join Date: Sep 2006
Location: Pleasant Hill, CA
Send a message via Skype™ to Wavebourn
Quote:
Originally Posted by scott wurcer View Post
That output stage is a throwback to things like Futterman OTL.

Here's one, the hot chassis is an added feature. Does anyone know if this predates Kaneda?
If you mean that "practical schematic" that John had shown, it is quite different. There 2 currents were applied to resistors between gates and sources of each particular output device. Here triodes loaded on resistors supply voltage signals to grids of common cathode and common anode stages. Gross imbalance. John's version is much better.
__________________
The Devil is not so terrible as his math model is!
  Reply With Quote
Old 30th August 2012, 11:43 PM   #27089
diyAudio Member
 
Chris Hornbeck's Avatar
 
Join Date: May 2011
Location: Little Rock
When Yamaha brought out the giant-JFET-output model B1 amplifier (below) they had a good white paper about the output stage drive, but I can't find it online. I'll see if I can figure out a way if anybody's interested.

http://my.coolala.net/upload0713/201...1286557087.gif

Thanks,
Chris
  Reply With Quote
Old 31st August 2012, 12:05 AM   #27090
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Quote:
Originally Posted by Chris Hornbeck View Post
When Yamaha brought out the giant-JFET-output model B1 amplifier (below) they had a good white paper about the output stage drive, but I can't find it online. I'll see if I can figure out a way if anybody's interested.

http://my.coolala.net/upload0713/201...1286557087.gif

Thanks,
Chris
I don't see the point, these circuits are bandaids when you can make only one good flavor of device. Topologically you can show the same crossover issues with low quiescient bias as if you had a class A/B output and the PSRR is do-do.
__________________
"This logos holds always but humans always prove unable to understand it, both before hearing it and when they have first heard it."
  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



New To Site? Need Help?

All times are GMT. The time now is 10:06 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