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

Pass Labs This forum is dedicated to Pass Labs discussion.

Pass Discrete Opamp in DIP-8 Package
Pass Discrete Opamp in DIP-8 Package
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 9th April 2008, 10:30 AM   #31
jacco vermeulen is offline jacco vermeulen  Netherlands
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curašao
Send a message via Yahoo to jacco vermeulen
6 nV/√Hz ?
__________________
Why does it hurt when I Pee ? (Ay Ay Ay https://www.youtube.com/watch?v=w5fLGWrHouk)
  Reply With Quote
Old 10th April 2008, 01:09 PM   #32
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
We have done some more simulation and testing. Basically you can get stability for almost any gain other than +1 (unity gain buffer). But then for unity gain buffer, one might just as well use a pair of BF862 without any feedback.

For gain of -1 (unity gain inverting), we found that it is best not to use the compensation cap but just a cap in parallel the feedback resistor. Bandwidth is never a problem, always way above 200kHz.

We plan to test this in a Buffer-Filter-Buffer phono preamp with single stage gain of 100. Will take a while. Need to make and trim 4 new ones.


Patrick
  Reply With Quote
Old 10th April 2008, 11:11 PM   #33
flg is offline flg  United States
diyAudio Member
 
flg's Avatar
 
Join Date: Jul 2005
Location: North East
  Reply With Quote
Old 20th April 2008, 06:33 AM   #34
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
> We plan to test this in a Buffer-Filter-Buffer phono preamp

While waiting for potting compound ....


Patrick
Attached Images
File Type: jpg 080420 rjm4 top s1.jpg (99.2 KB, 4383 views)
  Reply With Quote
Old 20th April 2008, 06:35 AM   #35
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
One more ....
Attached Images
File Type: jpg 080420 rjm4 iso s1.jpg (96.7 KB, 4258 views)
  Reply With Quote
Old 20th April 2008, 04:59 PM   #36
Justcallmedad is offline Justcallmedad  France
diyAudio Member
 
Justcallmedad's Avatar
 
Join Date: Jun 2004
Location: Paris
Thumbs up Waouhhh

Bravo Patrick !!! Congratulations !!! Very very nice job really !
__________________
Richard Perez
  Reply With Quote
Old 20th April 2008, 05:53 PM   #37
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
Thanks Richard.
Was an interesting challenge and real fun to realise the design.
Hope to report on listening test in a month or so.


Patrick
  Reply With Quote
Old 21st April 2008, 08:39 AM   #38
peranders is offline peranders  Sweden
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: G÷teborg, Sweden
Pass Discrete Opamp in DIP-8 Package
Nice work but what the positive results be compared to using a high performance opamp? Have you ever considered to make a current feedback "opamp"? You can make those rather simple and compact also.
__________________
/Per-Anders (my first name) or P-A as my friends call me
PA03 LM4780 amplifier group buy, SIGN UP HERE for the group buy 0 boards left. 118 paid.
  Reply With Quote
Old 21st April 2008, 09:41 AM   #39
bays_9a5tt is offline bays_9a5tt  Croatia
diyAudio Member
 
bays_9a5tt's Avatar
 
Join Date: Jan 2005
Location: Zagreb
Quote:
Originally posted by EUVL
One more ....
I love the shape of top layer - reminds me of '70s hand-drawn PCBs, just inverted :-)
Nice work, BTW
  Reply With Quote
Old 21st April 2008, 09:41 AM   #40
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally posted by EUVL
But then for unity gain buffer, one might just as well use a pair of BF862 without any feedback.
is that a FET follower fed from a CCS that you're suggesting?
or a cascoded FET?
or what?
__________________
regards Andrew T.
Sent from my desktop computer using a keyboard
  Reply With Quote

Reply


Pass Discrete Opamp in DIP-8 PackageHide 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

Similar Threads
Thread Thread Starter Forum Replies Last Post
opamp package converter question rtate Digital Line Level 4 13th January 2009 10:53 PM
Single or Dual opamp package? JojoD818 Solid State 15 19th December 2003 02:09 PM


New To Site? Need Help?

All times are GMT. The time now is 09:00 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki