Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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 12th September 2012, 10:34 PM   #1751
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
what you are going to do with the bird ?

keep it in cage ?

as long you can see it , with naked eye or .... , any bird is same good .

point is in looking at it , not having prettiest one

you started to look at one of yours , recently - Compound amps .
__________________
my Papa is smarter than your Nelson !
tnx to clean thread ; Cook Book ; PSM LS Cook Book ; Baby Diyaudio FORUM ; Mighty ZM's Bloggg;I'm dumb ; Papatreasure
  Reply With Quote
Old 12th September 2012, 10:49 PM   #1752
lhquam is offline lhquam  United States
diyAudio Member
 
Join Date: Mar 2010
Location: Olalla, Oregon: Land of the 100 Valleys
Using a hint from Nelson's "F6 Conceptual Schematic" about V2+ and V2-, I came up with another approach to the bias voltage generation using TL431 voltage regulators in a TO-92 package. This generates both the reduced voltages for the input JFETs and regulated voltages for the bias circuits, making it very insensitive to the V1, V2 rail voltage fluctuations.
Attached Images
File Type: jpg F6-VR-1-scm.jpg (81.7 KB, 269 views)
  Reply With Quote
Old 12th September 2012, 10:59 PM   #1753
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
Quote:
Originally Posted by lhquam View Post
Using a hint from Nelson's "F6 Conceptual Schematic" about V2+ and V2-, I came up with another approach to the bias voltage generation using TL431 voltage regulators in a TO-92 package. This generates both the reduced voltages for the input JFETs and regulated voltages for the bias circuits, making it very insensitive to the V1, V2 rail voltage fluctuations.
do you get a significant change in performance?
__________________
...Shape the sound , Man!
  Reply With Quote
Old 12th September 2012, 11:11 PM   #1754
lhquam is offline lhquam  United States
diyAudio Member
 
Join Date: Mar 2010
Location: Olalla, Oregon: Land of the 100 Valleys
Quote:
Originally Posted by buzzforb View Post
do you get a significant change in performance?
The difference is more tolerance to rail voltage variations. No known difference otherwise.

Last edited by lhquam; 12th September 2012 at 11:21 PM.
  Reply With Quote
Old 12th September 2012, 11:20 PM   #1755
lhquam is offline lhquam  United States
diyAudio Member
 
Join Date: Mar 2010
Location: Olalla, Oregon: Land of the 100 Valleys
I decided that it was a bad idea to try to economize on the resistor count by connecting the TL431 REF pin to the bias circuit potentiometer. Here is a revised schematic. This also restores the resistor charging the bias capacitor to somewhere near 10K ohms.
Attached Images
File Type: jpg F6-VR-1a-scm.jpg (86.3 KB, 262 views)
  Reply With Quote
Old 12th September 2012, 11:40 PM   #1756
diyAudio Member
 
Join Date: Jan 2012
Location: Pennsylvania
Blog Entries: 1
Quote:
Originally Posted by Zen Mod View Post
what you are going to do with the bird ?

keep it in cage ?

as long you can see it , with naked eye or .... , any bird is same good .

point is in looking at it , not having prettiest one

you started to look at one of yours , recently - Compound amps .
ZM. We are into philosophy, and it is all right. I am not telling any DIYer to do anything. You DIYers are the football, soccer and basketball stars on the field, and excell at what you do. I am a fan and an observer cheering and celebrating your achievements. I point connections and possible direction which are still within the bounds of the thread. lhquam has a clear objective to guess the design of Mr. Pass. What if Mr. Pass is operating his F6 in Class A/B? Slim chance in the possible view of many of you; but a possibility nonetheless because it was practiced with the old classic [nothing new] and sounded great.
I hope the comment you made on my thread Compound Power Amps is good. I did not understand it fully. It is a privilige for me to write on diyAudio; just like driving a car in the U.S.A. In all of my threads, I communicate ideas [some are weird], attach them with experiments and results like you, lhquam and others have done and continue to do. My posts are up for grabs by any DIYer to practice, laugh at, ridicule , enjoy etc. I am not selling anything; just passing therapeutic time.

Last edited by Antoinel; 12th September 2012 at 11:43 PM.
  Reply With Quote
Old 12th September 2012, 11:46 PM   #1757
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
I just forgot to put a smiley ........
Attached Images
File Type: gif lovac.gif (5.3 KB, 271 views)
File Type: gif rasta.gif (8.4 KB, 273 views)
__________________
my Papa is smarter than your Nelson !
tnx to clean thread ; Cook Book ; PSM LS Cook Book ; Baby Diyaudio FORUM ; Mighty ZM's Bloggg;I'm dumb ; Papatreasure
  Reply With Quote
Old 13th September 2012, 12:26 AM   #1758
lhquam is offline lhquam  United States
diyAudio Member
 
Join Date: Mar 2010
Location: Olalla, Oregon: Land of the 100 Valleys
Since my amplifier power needs are happily satisfied with less than 25W, I have no real interest in spending (wasting) time of Class-AB circuits.

Quote:
Originally Posted by Antoinel View Post
Your circuit is simple, robust and delivers great performance and sound. Mr. Pass may release his schematic in the future. In the interim you and others are telling the world of diyAudio the bigger potential of Teaser-6 and Franken6. Have you cast anything/performance in stone? You and buzzforb, ZM, and others are/have been the source of valuable info; not Mr. Pass. Who is gonna tell/show us how Teaser-6 and Franken6 perform as a Class A/B. Will it be Mr. Pass? I feel priviliged [and hope that others also do ] that you and others are sharing valuable info about your rendition of Conceptual F6. I care about what you, buzzforb and others are doing. I can't care about what Mr. Pass is doing because I know nothing about his activity, and thus why care about a high level secret; albeit valuable? I care about the proverbial bird at hand [Teaser6, Franken6] and not the one on a distant tree [F6 by Mr. Pass].
  Reply With Quote
Old 13th September 2012, 11:05 AM   #1759
lhquam is offline lhquam  United States
diyAudio Member
 
Join Date: Mar 2010
Location: Olalla, Oregon: Land of the 100 Valleys
Oops, the bottom cap (C2) should connect to V-, not ground. I am still tweaking a few things about this schematic, mostly resistor values.
The general idea looks pretty good.

Quote:
Originally Posted by lhquam View Post
I decided that it was a bad idea to try to economize on the resistor count by connecting the TL431 REF pin to the bias circuit potentiometer. Here is a revised schematic. This also restores the resistor charging the bias capacitor to somewhere near 10K ohms.
  Reply With Quote
Old 13th September 2012, 11:10 AM   #1760
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
I think nelson may use something similar to bias his PP output stages.
__________________
...Shape the sound , Man!
  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
New F6 diy coming soon ? Nounours18200 Pass Labs 37 31st August 2012 04:35 PM
Hi Vi F6 box ioro Multi-Way 4 15th April 2012 08:27 PM
Whats happening with F6? jugoslavija Pass Labs 1 1st November 2011 07:39 AM
Hi-Vi F6 kkosiba Multi-Way 14 9th November 2007 08:38 AM
F6 traw Pass Labs 7 2nd November 2007 07:09 PM


New To Site? Need Help?

All times are GMT. The time now is 09:43 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