Pumpkin preamp - ordered by Steen , official making thread - Page 343 - 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 5th December 2012, 10:17 PM   #3421
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Hi Tony

easy peasy , for 2SJ109, matching by Idss :

source and gate to +9 (max 12V)

drain to mA meter red probe

mA meter black probe to gnd
__________________
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 6th December 2012, 03:51 PM   #3422
tonimxp is offline tonimxp  Italy
diyAudio Member
 
Join Date: Oct 2007
Location: Gallarate (VA)
Quote:
Originally Posted by Zen Mod View Post
Hi Tony

easy peasy , for 2SJ109, matching by Idss :

source and gate to +9 (max 12V)

drain to mA meter red probe

mA meter black probe to gnd
Hi Alex i have just tried and the results with 9v power voltage are this :

1 2sj109 91/92 mA

2 2sj109 53,5/53,5 mA

Please what do you think about different idss betwen 1 and 2 jfet?

I also have four 2sj74 bl 6g and i tried with same idss matching method.
the results are this:

1 2sj74 10,10mA
2 2sj74 10,10mA
3 2sj74 10,04mA
4 2sj74 10,07mA

Please can you advise me what to use for your Aleph J Babbelfish?

Thanks in advance

Last edited by tonimxp; 6th December 2012 at 04:19 PM.
  Reply With Quote
Old 6th December 2012, 04:10 PM   #3423
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
they're fakes

according to 2SJ109 datasheet , there are 3 groups of Idss for exactly same test setup :

GR , BL , and V

if you made test as I wrote ( see enclosed sketch) , they're fakes without doubts

look at 2Sj74 side , presume that Rs is zero , for your case of measuring (full) Idss

http://jm.plantefeve.pagesperso-orange.fr/2SJ109.pdf
Attached Images
File Type: jpg matching.JPG (17.7 KB, 178 views)
File Type: gif 2SJ109 class.gif (3.9 KB, 175 views)
__________________
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 6th December 2012, 04:28 PM   #3424
tonimxp is offline tonimxp  Italy
diyAudio Member
 
Join Date: Oct 2007
Location: Gallarate (VA)
Quote:
Originally Posted by Zen Mod View Post
they're fakes

according to 2SJ109 datasheet , there are 3 groups of Idss for exactly same test setup :

GR , BL , and V

if you made test as I wrote ( see enclosed sketch) , they're fakes without doubts

look at 2Sj74 side , presume that Rs is zero , for your case of measuring (full) Idss

http://jm.plantefeve.pagesperso-orange.fr/2SJ109.pdf
Yes my Rs is zero and my type are BL ,so...what should be the correct IDSS (if they were genuine) in my case, with 9V and without Rs?
  Reply With Quote
Old 6th December 2012, 04:35 PM   #3425
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
see picture above

6 to 12mA
__________________
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 6th December 2012, 04:50 PM   #3426
tonimxp is offline tonimxp  Italy
diyAudio Member
 
Join Date: Oct 2007
Location: Gallarate (VA)
Quote:
Originally Posted by Zen Mod View Post
see picture above

6 to 12mA
I have to open a dispute on ebay, please with what voltage value (with my set up measurement) should get from -6 mA to-12mA Idss?
  Reply With Quote
Old 6th December 2012, 04:52 PM   #3427
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
as I said already - in range of 9 to 12V

what you got are probably re-labelled bjt's
__________________
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 6th December 2012, 07:01 PM   #3428
tonimxp is offline tonimxp  Italy
diyAudio Member
 
Join Date: Oct 2007
Location: Gallarate (VA)
Quote:
Originally Posted by Zen Mod View Post
as I said already - in range of 9 to 12V

what you got are probably re-labelled bjt's
thanks Alex
  Reply With Quote
Old 6th December 2012, 07:56 PM   #3429
tonimxp is offline tonimxp  Italy
diyAudio Member
 
Join Date: Oct 2007
Location: Gallarate (VA)
So...about my four 2sj74 bl 6g

1 2sj74 10,10mA
2 2sj74 10,10mA
3 2sj74 10,04mA
4 2sj74 10,07mA

Are they ok to use for your Aleph J Babbelfish?

And about my post n3420 of this tread what do you think?

For 2sj310 (Q1 and Q2) of Pumpkin i have found those values of Vgs:

180-184-(187-188)-(193-196) mV so i have match as in parenthesis.
The current draw is set to 5mA for five minutes test time.

I have to ask you your comments for results.




Thanks in advance
  Reply With Quote
Old 6th December 2012, 09:21 PM   #3430
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Quote:
Originally Posted by tonimxp View Post
So...about my four 2sj74 bl 6g

1 2sj74 10,10mA
2 2sj74 10,10mA
3 2sj74 10,04mA
4 2sj74 10,07mA

Are they ok to use for your Aleph J Babbelfish?
perfect

just take care of pinout

Quote:
Originally Posted by tonimxp View Post
......
And about my post n3420 of this tread what do you think?

For 2sj310 (Q1 and Q2) of Pumpkin i have found those values of Vgs:

180-184-(187-188)-(193-196) mV so i have match as in parenthesis.
The current draw is set to 5mA for five minutes test time.

I have to ask you your comments for results.




Thanks in advance

they're good , of course

attached pic - view from top (as a bird ....... or Batman )
Attached Images
File Type: jpg 2sj109-to-2sj74.jpg (71.2 KB, 161 views)
__________________
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

Last edited by Zen Mod; 6th December 2012 at 09:24 PM.
  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



New To Site? Need Help?

All times are GMT. The time now is 02:34 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