John Curl's Blowtorch preamplifier part II - Page 1304 - 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 21st June 2011, 10:20 AM   #13031
loek is offline loek  Netherlands
diyAudio Member
 
Join Date: Feb 2005
Location: The Hague
Default M800

Quote:
Originally Posted by Charles Hansen View Post
And I would also be curious to see the schematic.
ラックスマン株式会社|ホーム製品情報|ステレオパワーアンプM-800A - LUXMAN
Only the pics I can understand....
Regards, Loek
Attached Images
File Type: gif LuxmanM800.gif (138.3 KB, 327 views)
File Type: jpg LuxmanM800inside.jpg (245.9 KB, 327 views)

Last edited by loek; 21st June 2011 at 10:28 AM.
  Reply With Quote
Old 21st June 2011, 04:25 PM   #13032
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
So far, so good, but the 'essence is in the 'triangles'.
  Reply With Quote
Old 21st June 2011, 06:49 PM   #13033
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
We need more 'info' in order to define this design.
  Reply With Quote
Old 21st June 2011, 06:54 PM   #13034
diyAudio Member
 
Join Date: Nov 2008
Location: Oakmont PA
John the picture looks like SIP package op amps
  Reply With Quote
Old 21st June 2011, 06:58 PM   #13035
diyAudio Member
 
Johnloudb's Avatar
 
Join Date: Feb 2008
yep, I see the little buggers, and sockets no less.
__________________
My Website: Hyperacusis, Tinnitus, My Story
  Reply With Quote
Old 21st June 2011, 10:39 PM   #13036
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
I bet they are National.
  Reply With Quote
Old 22nd June 2011, 04:20 AM   #13037
diyAudio Member
 
Chris Hornbeck's Avatar
 
Join Date: May 2011
Location: Little Rock
Hi Ladies and Germans,

Although I'm still working my way through the 13000+ posts in Part Deux, I wonder if it's appropriate to present a circuit element derived from the famous John Curl "boxer" input stage. The circuit is a "boxer" second stage ("VAS" in op-amp speak) with its advantages, although I'm using a half circuit version for a phono equalizer.

If interested, let me know, or if OT, also let me know. I've enjoyed these two threads enormously, and much, much thanks to all.

Chris
  Reply With Quote
Old 22nd June 2011, 04:28 AM   #13038
diyAudio Member
 
ostripper's Avatar
 
Join Date: May 2008
Location: Smoky Mountains , Tennessee
Quote:
Originally Posted by john curl View Post
I bet they are National.
Nope , toshiba custom SIP . Same as the JVC super A , custom manufactured for luxman. A good way to keep the IP secret ... put it in a proprietary IC.

OS
__________________
Mongrel website , always current and updated :
http://www.fidelityforce.com/ostripper
  Reply With Quote
Old 22nd June 2011, 04:45 AM   #13039
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
John,

Quote:
Originally Posted by john curl View Post
So far, so good, but the 'essence is in the 'triangles'.
The Design is the same "Only Distortion Feedback" as the B1000.

MJ had pretty extensive articles on this. The "Op-Amp" shown is actually no op-amp, but a discrete ciruit.

The "forward" path of the Amp is a simple single ended 2-stage open loop BJT Circuit, driving one side of the output stage with high impedance.

The "Op-Amp" only receives the extracted error, amplifies it suitably and applies it to the other side of the output stage.

Both "Distortion feedback" and "Signal" are mixed at the input of the output stage.

I personally would suggest that contrary to OSTrippers comments the design is quite unusual and interesting. I can see the possibility for it to provide better tradeoffs between "zero feedback" and "ton's of feedback" without attracting the undesirable side-effects of either...

Ciao T
  Reply With Quote
Old 22nd June 2011, 05:33 AM   #13040
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
I am thankful for that. I would not liked to have been passed over by an IC chip. '-)
  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 06:51 PM.


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

Content Relevant URLs by vBSEO 3.3.2