f4 parts substitution - 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 10th July 2010, 10:42 PM   #1
diyAudio Member
 
Join Date: Oct 2007
Location: melbourne
Default f4 parts substitution

hi
i would like to use my 2sj109 in my diy f4 but i notice it has seven legs as oposed to six when using the normal combination of 108/ 389
what is this extra leg ?

i have not got the output devices yet are there any options here that would drop in and be an improvement on the originals ,toshiba or semisouth perhaps ?

thanks in advance for any help or advice

regards sheafer
  Reply With Quote
Old 10th July 2010, 11:09 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
google for 2SJ109 ; pdf file

7-th ( middle ) pin is substrat ....... in fact - nothing .

btw- I don't know where in F4 you'll use 2SJ109 ?

you mean using pairs for both input Jfets , meaning on 2SJ109 and 2SK389 ?
__________________
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 11th July 2010, 02:35 AM   #3
diyAudio Member
 
Join Date: Oct 2007
Location: melbourne
hi zen mod
seems i must have buggered up as usual

i thought i could replace the 108 and 389 with a single j109 per channel
as i have heaps of j109 and canot find anywhere the 389 or 108
what alternatives do i have ?

regards sheafer
  Reply With Quote
Old 11th July 2010, 07:52 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 can't do this
2SJ109 is nothing else than 2pcs of 2SJ74 in one case

same polarity jfets ........ and you need one of each polarity
__________________
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 14th July 2010, 08:40 AM   #5
diyAudio Member
 
Join Date: Oct 2007
Location: melbourne
thanks zen mod
now i understand ,
so i need the opposite polarity to the or 2sj74

its a shame as i have 8 new 2sj109 bl here doing nothing

i have an aleph 2 clone that is running on high bias 7.2 a and low voltage (25/0/25 sec) for my esl speakers ,perhaps i could convert it to jfet input using the 2sj109

cheers
  Reply With Quote
Old 14th July 2010, 08:52 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
Quote:
Originally Posted by slr 5000 View Post
......

i have an aleph 2 clone that is running on high bias 7.2 a and low voltage (25/0/25 sec) for my esl speakers ,perhaps i could convert it to jfet input using the 2sj109

cheers
yes , you can ;

post exact schematic of your Aleph 2 and I'll draw needed changes for you ......
__________________
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 14th July 2010, 10:18 AM   #7
diyAudio Member
 
Join Date: Oct 2007
Location: melbourne
thank you zen mod

it is built from the kkk pcb boards
i will get the schematic tommorow and post it

many thanks
sheafer
  Reply With Quote
Old 15th July 2010, 07:21 AM   #8
diyAudio Member
 
Join Date: Oct 2007
Location: melbourne
hi zen mod
here you go regards sheafer
Attached Images
File Type: gif aleph-2.gif (17.1 KB, 153 views)
  Reply With Quote
Old 15th July 2010, 09:19 AM   #9
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
will you manage with this ?

Jfet input for Aleph 60?
__________________
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 15th July 2010, 11:12 AM   #10
diyAudio Member
 
Join Date: Oct 2007
Location: melbourne
hi zen mod
i think so ,i should replace the 4x 2sj74 with 2x 2sj109 yes
also does mucho mean remove ?

regards sheafer
  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
Threshold 400a Parts Substitution & Mods. sulky Pass Labs 24 11th February 2013 03:20 AM
FS: F4 PCBs and critical parts jrebman Swap Meet 5 13th October 2009 10:03 PM
Orion HCCA amp parts substitution question ECM Car Audio 33 5th January 2008 10:55 AM
Driver substitution Glowbug Multi-Way 4 10th January 2007 09:45 PM
PARTS PARTS PARTS!!! Infocus Powerview 820, triplet, ballast, light, power supply!!! marioinla Swap Meet 1 31st August 2004 04:22 PM


New To Site? Need Help?

All times are GMT. The time now is 02:53 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