Preamp-Buffers - simple idea - Page 2 - 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 27th March 2013, 03:43 AM   #11
diyAudio Member
 
Stefanoo's Avatar
 
Join Date: Apr 2006
Location: italia - ora USA -WI
Quote:
Originally Posted by georgehifi View Post
Hi Calvin, here is one that John Curl seemed to like and the DC offset trim works a treat. If you could sim it that would be nice. I'm using it and it sounds better than A in your first post which I had before.

Cheers George
Interesting. I wonder how it would compare to C and D.

EDIT: btw IMHO A sounds better than B
__________________
Stefano
  Reply With Quote
Old 27th March 2013, 03:49 AM   #12
diyAudio Member
 
Joachim Gerhard's Avatar
 
Join Date: Mar 2009
That is a driven cascode. It can be improved much and i have shown elsewhere.
  Reply With Quote
Old 27th March 2013, 03:50 AM   #13
diyAudio Member
 
Joachim Gerhard's Avatar
 
Join Date: Mar 2009
My comment is for post 10.
  Reply With Quote
Old 27th March 2013, 03:51 AM   #14
diyAudio Member
 
Joachim Gerhard's Avatar
 
Join Date: Mar 2009
In what way does it sound better ?
  Reply With Quote
Old 27th March 2013, 04:00 AM   #15
diyAudio Member
 
Stefanoo's Avatar
 
Join Date: Apr 2006
Location: italia - ora USA -WI
Quote:
Originally Posted by Joachim Gerhard View Post
In what way does it sound better ?
Still referring to post 10? I would be curious to know that too
__________________
Stefano
  Reply With Quote
Old 27th March 2013, 06:06 AM   #16
diyAudio Member
 
georgehifi's Avatar
 
Join Date: Sep 2003
Location: Manly Australia (Jewel of the Pacific)
Send a message via MSN to georgehifi
Quote:
Originally Posted by Joachim Gerhard View Post
In what way does it sound better ?
It seemed to have better more solid drive and dynamics into my Lightspeed Attenuator which is around 7k input, and the poweramp which is around 50k so it was seeing a total load of around 6k I don't know if this was the reason though.
Or maybe it's the fact that it can be dc coupled with the 250ohm trimpot which it is now trimed to .1mV offset, and steady once over the inital switch on bump of around .500mV but this quickly settles.

Cheers George
__________________
Avatar : Production Lightspeed Attenuator
www.lightspeedattenuator.com

Last edited by georgehifi; 27th March 2013 at 06:11 AM.
  Reply With Quote
Old 27th March 2013, 10:37 AM   #17
gk7 is offline gk7
diyAudio Member
 
Join Date: Oct 2007
Location: Vienna, Austria
What to use as replacement for the SST4391 (out of production) ?
  Reply With Quote
Old 27th March 2013, 11:36 AM   #18
dadod is offline dadod  Croatia
diyAudio Member
 
dadod's Avatar
 
Join Date: Apr 2006
Location: Zagreb
Quote:
Originally Posted by georgehifi View Post
Hi Calvin, here is one that John Curl seemed to like and the DC offset trim works a treat. If you could sim it that would be nice. I'm using it and it sounds better than A in your first post which I had before.

Cheers George
You can improve this to bootstrap cascode.
Attached Images
File Type: jpg fetbuffer%202%20+%20dc%20offset%20adjust.jpg (43.2 KB, 1147 views)
  Reply With Quote
Old 27th March 2013, 12:04 PM   #19
gk7 is offline gk7
diyAudio Member
 
Join Date: Oct 2007
Location: Vienna, Austria
Quote:
Originally Posted by georgehifi View Post
... here is one that John Curl seemed to like ...
Im not aware of any John Curl schematic where this buffer was used.
(Its from a chinese ebay seller if Im not mistaken.)

What John did use, is a similar configuration without cascode for the
output of the JC-2 (ML-1) phono stage. Its within the feedback loop
in this phono stage, though.
  Reply With Quote
Old 27th March 2013, 12:09 PM   #20
diyAudio Member
 
Join Date: Jan 2013
Quote:
Originally Posted by dadod View Post
You can improve this to bootstrap cascode.
Arent the Jfets in the original post 10 already bootstrapped, the only diffrence is that you are removing the 22 ohm resistors.
  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
phono preamp 'input buffers'. fap Analogue Source 43 9th December 2011 08:46 PM
eBay&etc cheap tube buffers/preamp .. anything good? pedromreis Tubes / Valves 9 4th November 2011 03:51 PM
Preamp Input Selector & Buffers Devil_H@ck Chip Amps 9 2nd May 2004 10:29 AM
A simple chassis idea Peter Daniel Everything Else 34 5th December 2002 12:57 AM
Preamp design question -- where to put buffers? gretzteam Solid State 6 1st March 2002 04:36 AM


New To Site? Need Help?

All times are GMT. The time now is 07:27 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