Discrete Opamp Open Design - Page 97 - 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 15th September 2012, 11:39 PM   #961
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
I prefer minimal series thru-path, BUT not minimum active parts for its own sake. IF you create an arbitrary maximum of active devices, you reduce the field of choice AND the potential optimization of any particular circuit. I think that Einstein said something like:
Everything should be made as simple as possible, but no simpler. '-)

Last edited by john curl; 15th September 2012 at 11:44 PM.
  Reply With Quote
Old 16th September 2012, 12:02 AM   #962
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
OK. So, make opamp as good as possible and as simple as possible. but no simpler.
Now where were we??
  Reply With Quote
Old 16th September 2012, 12:21 AM   #963
diyAudio Member
 
Join Date: Dec 2003
Location: Munich
...that's a matter of taste.
To me our OP amp discussion has moved to much to high component count.

I like Gerhard's idea to settle an symmetric version of the LinuxBuffer.
Unfortunately my understanding how to symmetrize the buffer leads to
higher component count than Gerhard's schematic...
Just a thought, but not simulated.
Attached Images
File Type: jpg LinuxBufferSym.JPG (24.1 KB, 343 views)
  Reply With Quote
Old 16th September 2012, 12:45 AM   #964
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
Quote:
Originally Posted by ChocoHolic View Post
...that's a matter of taste.
To me our OP amp discussion has moved to much to high component count.

I like Gerhard's idea to settle an symmetric version of the LinuxBuffer.
Unfortunately my understanding how to symmetrize the buffer leads to
higher component count than Gerhard's schematic...
Just a thought, but not simulated.
Symmetry IS important.
Last year I was making just a buffer to entertain myself and was up to 12 transistors and heading towards more before I said - 'stop'. Way too many transistors.... but the distortion was unmeasureable (really low). IMO I decided for myself that the lowest harmonic content couldnt be the only goal. What other parameters make for a better audio circuit besides noise, IM and harmonic content? How important is CMR in audio? PSR is important but can be divided between power supply and circuit.

Last edited by RNMarsh; 16th September 2012 at 12:56 AM.
  Reply With Quote
Old 16th September 2012, 02:49 AM   #965
diyAudio Member
 
Chris Hornbeck's Avatar
 
Join Date: May 2011
Location: Little Rock
With +/- 24 VDC supplies, a final stage of supply decoupling might be included in the package. Maybe even with a professional +24 dbu output? It's a good place to put a final supply decoupler anyhoo.

Thanks,
Chris
  Reply With Quote
Old 16th September 2012, 02:59 AM   #966
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
I just did it Richard! '-)
  Reply With Quote
Old 16th September 2012, 03:00 AM   #967
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
Takes more parts, Chris, look at my example.
  Reply With Quote
Old 16th September 2012, 03:21 AM   #968
bcarso is offline bcarso  United States
diyAudio Member
 
Join Date: May 2005
Location: Canoga Park, California
Quote:
Originally Posted by john curl View Post
I prefer minimal series thru-path, BUT not minimum active parts for its own sake. IF you create an arbitrary maximum of active devices, you reduce the field of choice AND the potential optimization of any particular circuit. I think that Einstein said something like:
Everything should be made as simple as possible, but no simpler. '-)
Agree . Minimize the through path, but the supporting cast should be as required. Damn the expense LOL.
  Reply With Quote
Old 16th September 2012, 04:38 AM   #969
RNMarsh is offline RNMarsh  United States
diyAudio Member
 
RNMarsh's Avatar
 
Join Date: May 2012
Location: 2457 Cascade Trail; Cool, CA. 95614
[QUOTE=bcarso;3166631]Agree . Minimize the through path, but the supporting cast should be as required. QUOTE]

I agree, too. I count a cascode as one and dont count CCS et al.

John. You just did IT? What does - you just did it mean?

Whats the best power supply topology... series or shunt reg or both?
  Reply With Quote
Old 16th September 2012, 12:02 PM   #970
diyAudio Member
 
Join Date: Sep 2007
Send a message via Yahoo to linuxguru
Just for historical interest, here's one of the very conventional predecessors to the CCB. It's fairly ordinary in distortion, but has high bandwidth. It's probably easier to make a symmetric version of this one...
Attached Images
File Type: jpg ccascode_prev1.jpg (60.2 KB, 286 views)
  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
Discrete OPAMP audio-gd Vendor's Bazaar 27 20th September 2012 05:02 PM
discrete opamp help blackpowderaudio Parts 0 16th December 2009 04:46 PM
THAT transistor headphone amp (250ma discrete opamp) design sanity check. Russ White Headphone Systems 19 13th December 2007 01:52 PM


New To Site? Need Help?

All times are GMT. The time now is 12:03 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