Operating points of Semisouth JFETs - diyAudio
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 20th October 2012, 08:54 PM   #1
316a is offline 316a  England
diyAudio Member
 
316a's Avatar
 
Join Date: Dec 2002
Location: West London
Default Operating points of Semisouth JFETs

Currently running R085 as choke loaded source followers at 1.7A / 5.2V bias with a 22V supply and getting some nice sounds Wondering what the general consensus is with regards to good sounding operating points with these devices

316A
  Reply With Quote
Old 20th October 2012, 10:09 PM   #2
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
what's wrong with 22V across R085?

with 5V2 bloody thing is starving
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 20th October 2012, 11:20 PM   #3
316a is offline 316a  England
diyAudio Member
 
316a's Avatar
 
Join Date: Dec 2002
Location: West London
Quote:
Originally Posted by Zen Mod View Post
what's wrong with 22V across R085?

with 5V2 bloody thing is starving
There is almost 17V across the R085 and 5.2V between source and 0V . I wouldn't call that starving

316A
  Reply With Quote
Old 21st October 2012, 01:04 AM   #4
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
you weren't clear in first post


what is meaning of 5V2 between source and 0 ?
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 21st October 2012, 08:22 AM   #5
316a is offline 316a  England
diyAudio Member
 
316a's Avatar
 
Join Date: Dec 2002
Location: West London
Quote:
Originally Posted by Zen Mod View Post
you weren't clear in first post


what is meaning of 5V2 between source and 0 ?
I thought I was perfectly clear , this is very basic stuff R085 is self biased and it's configured as a source follower . It's a normally on device and the gate is referenced to 0V so the 5.2V of bias is formed across the DCR of the choke/resistor load .

316A
  Reply With Quote
Old 21st October 2012, 08:59 AM   #6
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
it will be clear that you wrote SJDP

anyway , you're pretty good regarding working conditions
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 21st October 2012, 08:21 PM   #7
diyAudio Member
 
Join Date: Jul 2012
Location: Everett, Washington
Is it difficult to get the Semisouth power Fets?
  Reply With Quote
Old 21st October 2012, 08:38 PM   #8
316a is offline 316a  England
diyAudio Member
 
316a's Avatar
 
Join Date: Dec 2002
Location: West London
Element14/Farnell or Teabag on DIYaudio

316A
  Reply With Quote
Old 21st October 2012, 08:53 PM   #9
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Tea Bag is your man
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  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
SemiSouth SiC Power JFETs RocketScientist Solid State 105 19th February 2012 08:02 PM
Two Audio Grade Semisouth SIC JFets vdi_nenna Pass Labs 19 14th February 2012 06:11 AM
Semisouth SiC JFETs: SJEP120R100 or SJEP170R550 better for building amp? zhoufang Pass Labs 32 2nd September 2010 05:41 AM
Pre-order for SemiSouth SiC JFETs, check out the price! zhoufang Swap Meet 9 11th March 2010 03:03 AM


New To Site? Need Help?

All times are GMT. The time now is 06:41 PM.


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