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.

Buffer with Dual N-Ch Jfets and Dual Power Supply
Buffer with Dual N-Ch Jfets and Dual Power Supply
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 March 2019, 07:27 PM   #21
vdi_nenna is offline vdi_nenna  United States
diyAudio Member
 
vdi_nenna's Avatar
 
Join Date: Oct 2000
Location: PA, USA
Buffer with Dual N-Ch Jfets and Dual Power Supply
Can I get an extra set of eyes on this?
Are the two B-grade BF861 Jfets listed exactly the same?

bf861 NXP RF JFET Transistors | Mouser

thanks.
__________________
I build, therefore I am.
Do not create problems where there are none.
  Reply With Quote
Old 15th March 2019, 07:46 PM   #22
rco3 is offline rco3  United States
diyAudio Member
 
Join Date: Oct 2006
Location: Space Coast, FL
The ,215 parts come on a reel of 3,000. The ,235 parts come on a reel of 10,000. If you are producing large numbers of final product, you may find that ordering a reel of 10K gives you different statistics for part-to-part variation than three or four reels of 3,000. If you are buying a couple of dozen for your personal projects, I suspect the difference is irrelevant.
  Reply With Quote
Old 15th March 2019, 07:50 PM   #23
vdi_nenna is offline vdi_nenna  United States
diyAudio Member
 
vdi_nenna's Avatar
 
Join Date: Oct 2000
Location: PA, USA
Buffer with Dual N-Ch Jfets and Dual Power Supply
Going for the cheaper part.
__________________
I build, therefore I am.
Do not create problems where there are none.
  Reply With Quote
Old 21st March 2019, 01:14 PM   #24
vdi_nenna is offline vdi_nenna  United States
diyAudio Member
 
vdi_nenna's Avatar
 
Join Date: Oct 2000
Location: PA, USA
Buffer with Dual N-Ch Jfets and Dual Power Supply
I wimped out and only picked up 25 qty BF861 and 25 qty J113. Also 50 SOT-23 to SIP adapters. Still have a bunch of 2SK170 ranging from 3mA to over 20mA Idss.

Soekris DAC's output is off the R2R array and said to be 1.2V. Can a buffer be made with 15v rails that will produce at least that much output from the buffer?
B1 does it with +19v, so I'm guessing +/-15v rails can achieve at least 1.2v output.
__________________
I build, therefore I am.
Do not create problems where there are none.
  Reply With Quote
Old 29th March 2019, 06:06 PM   #25
vdi_nenna is offline vdi_nenna  United States
diyAudio Member
 
vdi_nenna's Avatar
 
Join Date: Oct 2000
Location: PA, USA
Buffer with Dual N-Ch Jfets and Dual Power Supply
Default Question about matching

When matching jfet Idss, when is the reading taken?
Is it the first mA reading one sees or after a certain amount of time or certain temp the jfet reaches?
I noticed the mA reading changes over time.
__________________
I build, therefore I am.
Do not create problems where there are none.
  Reply With Quote
Old 29th March 2019, 06:10 PM   #26
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
Steady state, as in operation.


Patrick
__________________
xen-audio.com
  Reply With Quote
Old 29th March 2019, 06:19 PM   #27
vdi_nenna is offline vdi_nenna  United States
diyAudio Member
 
vdi_nenna's Avatar
 
Join Date: Oct 2000
Location: PA, USA
Buffer with Dual N-Ch Jfets and Dual Power Supply
Thanks Patrick. So if running them at 15v, leave the test run at 15v for good amount of time.
__________________
I build, therefore I am.
Do not create problems where there are none.
  Reply With Quote
Old 29th March 2019, 06:22 PM   #28
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
Correct.

And if you use a heatsink (for thermal coupling), then it is best to test it as such.
But we are getting towards perfection now .....


Patrick
__________________
xen-audio.com
  Reply With Quote
Old 29th March 2019, 06:31 PM   #29
vdi_nenna is offline vdi_nenna  United States
diyAudio Member
 
vdi_nenna's Avatar
 
Join Date: Oct 2000
Location: PA, USA
Buffer with Dual N-Ch Jfets and Dual Power Supply
Happy to have finally gotten this question resolved.

Thanks!
__________________
I build, therefore I am.
Do not create problems where there are none.
  Reply With Quote
Old 31st March 2019, 02:47 AM   #30
vdi_nenna is offline vdi_nenna  United States
diyAudio Member
 
vdi_nenna's Avatar
 
Join Date: Oct 2000
Location: PA, USA
Buffer with Dual N-Ch Jfets and Dual Power Supply
I tested ten J113 jfets so far and lowest Idss so far is 17.17mA at 15v.
Can source resistance help?
__________________
I build, therefore I am.
Do not create problems where there are none.
  Reply With Quote

Reply


Buffer with Dual N-Ch Jfets and Dual Power SupplyHide 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
Dual jfets kinku Parts 5 20th April 2017 04:21 PM
Who wants 2SK194 Dual Jfets, C3381/A1349 Gr dual pair BJT? Junm Swap Meet 0 28th October 2015 03:17 PM
FS: Dual Jfets in metal can. Tarasque Swap Meet 2 26th July 2015 10:26 PM
Dual supply B1 Buffer andreaemme Pass Labs 0 5th January 2014 09:58 AM
Dual JFETS on EBAY Andypairo Swap Meet 7 11th December 2003 11:04 AM


New To Site? Need Help?

All times are GMT. The time now is 12:52 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki