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.

more complementary pairs than IRFP240/IRFP9240
more complementary pairs than IRFP240/IRFP9240
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 February 2018, 07:10 PM   #11
nigelwright7557 is offline nigelwright7557  United Kingdom
diyAudio Member
 
nigelwright7557's Avatar
 
Join Date: Apr 2008
Location: Carlisle, England
If you want much better matched pairs then consider quasi complementary outputs.
__________________
PCBCAD51 pcb design software. 2018 version out now with lower prices >> http://www.murtonpikesystems.co.uk
  Reply With Quote
Old 12th February 2018, 07:17 PM   #12
Zen Mod is offline Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
more complementary pairs than IRFP240/IRFP9240
Plenty of things to be obsessed with,long before best N-P pairing.....
__________________
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 12th February 2018, 07:19 PM   #13
nigelwright7557 is offline nigelwright7557  United Kingdom
diyAudio Member
 
nigelwright7557's Avatar
 
Join Date: Apr 2008
Location: Carlisle, England
Quote:
Originally Posted by Zen Mod View Post
Plenty of things to be obsessed with,long before best N-P pairing.....
I have never bothered matching transistors in amplifiers.
So long as there are current sharing resistors in outputs things should be fine.
__________________
PCBCAD51 pcb design software. 2018 version out now with lower prices >> http://www.murtonpikesystems.co.uk
  Reply With Quote
Old 12th February 2018, 07:32 PM   #14
woofertester is offline woofertester  United States
diyAudio Member
 
Join Date: Jun 2011
Quote:
Originally Posted by pchw View Post
The operating temperature inside the closed case will also make a difference. The jfets are very sensitive to the temperature. So, if you want to have a "closely" matched pairs (or quads) under your amp's operating condition, a temperature control jig is also needed.

FWIW, in the F5X project, NicMac acquires hundreds (if not thousands) Toshiba jfets and matched them in NNNNPPPP under Patrick's (EUVL, the F5X designer) matching instructions. There were not too many yields, and each set cost a fortune but still good price for what they are!!! However, they are not perfect match (still good match) in a different operating condition (can be affected by many factors in the DIY world :-)). No prematch set will satisfy each diyer's creativity.

One thing for sure, a matched pair at 9V is going to be many times better than a random pair. Given these jfets (Toshiba and Linear) are close to impossible to buy in bulk to match ourselves, we probably will have to accept the general 9V matching practice to get the project going and be happy.
This helps. Thanks. Where is the definitive write-up for matching the K170/J74 pairs? I have downloaded the write up on PassDiy but it was not totally clear to me.
  Reply With Quote
Old 12th February 2018, 07:43 PM   #15
Zen Mod is offline Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
more complementary pairs than IRFP240/IRFP9240
go to my blog , look for Borbely site blogpost
__________________
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 13th February 2018, 12:29 AM   #16
delecoy is offline delecoy  United States
diyAudio Member
 
delecoy's Avatar
 
Join Date: Nov 2011
Location: Austin, TX
Quote:
Originally Posted by Zen Mod View Post
Plenty of things to be obsessed with,long before best N-P pairing.....
I don't know much, but after years of reading posts here ( my original profile, lost somehow, would state 2005 for join date ) - I do know this to be true.
  Reply With Quote
Old 13th February 2018, 12:38 AM   #17
needtubes is offline needtubes  United States
diyAudio Member
 
Join Date: May 2003
Quote:
Originally Posted by marconi118 View Post
I mean matching the transconductance of the N and the P couple. Not the NN and PP matching
Irfp9140 has closer transconductance to the irfp240 than the irfp140
I have used IXTQ36N30P and IXTQ36P15P with great success. They seem a pretty decent match to me.
  Reply With Quote
Old 13th February 2018, 08:15 AM   #18
marconi118 is offline marconi118  Germany
diyAudio Member
 
Join Date: Mar 2008
My original questions were rather simple,

is the 9140 more complementary to the 240 than the 9240 ?
is the 244 or 340 more complementary to the 9240 than the 240?
is the irf630 more complementary to the irf9530 than the irf530?

asking because I have to buy new mosfets for PASS amps (F4 F5 etc)
  Reply With Quote
Old 13th February 2018, 08:27 AM   #19
Zen Mod is offline Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
more complementary pairs than IRFP240/IRFP9240
in case that nobody is having reply to your question right on top of their head , you need to search

read few linked posts , search for ilimzn's writings about 240/9140...... it's easy
__________________
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


more complementary pairs than IRFP240/IRFP9240Hide 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
FS: Matched 2SK2013, 2SJ313, IRFP240 and IRFP9240 pairs for the VFET amp build NicMac Swap Meet 4 21st December 2016 11:54 PM
Need hlep on this amp contain some irfp240 irfp9240 Leimahmood Solid State 8 28th July 2016 07:40 AM
IRFP240 / IRFP9240 MOSFETs danieljw Swap Meet 8 4th July 2009 01:51 AM
Wtb: Irfp240 / Irfp9240 folkeb Swap Meet 1 10th March 2009 10:18 AM
IRFP240 + IRFP9240 -- pairs jackinnj Swap Meet 1 2nd June 2006 02:22 AM


New To Site? Need Help?

All times are GMT. The time now is 01:20 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki