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.

Replacement For Toshiba 2SK170/2SJ74
Replacement For Toshiba 2SK170/2SJ74
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 14th May 2018, 04:30 AM   #131
6L6 is offline 6L6  United States
diyAudio Moderator
 
6L6's Avatar
 
Join Date: Oct 2010
Location: Denver, Colorado
Replacement For Toshiba 2SK170/2SJ74
Correct. B&D sells a “pair” as one K170 and one J74 of the same grade. Not measured nor matched. Still, not a bad price.

I bought some K2013/J313 from them for a BA-3 project (no matching required) and it worked perfectly.
  Reply With Quote
Old 14th May 2018, 01:15 PM   #132
toxic ingestion is offline toxic ingestion  United States
diyAudio Member
 
Join Date: Jul 2012
Location: Arizona
Oops. You are right. They always sold matching when I looked previously, but it is not mentioned now. I bought 50 of each some time ago and ended up with the great majority matching.
  Reply With Quote
Old 18th May 2018, 08:45 PM   #133
Soundhappy is offline Soundhappy  France
diyAudio Member
 
Soundhappy's Avatar
 
Join Date: Oct 2012
Location: Montpellier near Mediterranean Sea France
First positive feedback about new seller of 2SJ74| 2SK170 jfet's are show on line today.
Replacement For Toshiba 2SK170/2SJ74
Attached Images
File Type: jpg 8C53F529-987C-4C17-ACF0-597F3032CFA5.JPG (325.2 KB, 897 views)
__________________
class A amplifiers with full range speakers
sings like angels in heaven
  Reply With Quote
Old 23rd May 2018, 08:15 AM   #134
sarathssca is offline sarathssca  India
diyAudio Member
 
Join Date: May 2014
can low power MOSFETS like zvn3310 - zvp3310 be used at the input stage of preamps/amps in place of low power jFETs 2sk170 - 2sj74, in the complementary input stages like in BA-3 or in LTP input stages as in aleph series, BA-1/BA-2?
(may be cascoded to reduce the input capacitance in either cases)
  Reply With Quote
Old 23rd May 2018, 11:27 PM   #135
Nelson Pass is offline Nelson Pass  United States
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
Replacement For Toshiba 2SK170/2SJ74
As a concept, yes. However, other characteristics aside, these Jfets are
depletion mode, so they will conveniently bias themselves up without
external circuitry. The ZVN and ZVP have to be given either a bias
voltage at the Gates (relative to their Source pins) or biased by a
current source of some kind. In this sense, it is often simply a matter
of convenience to use the Jfets.
  Reply With Quote
Old 24th May 2018, 02:51 PM   #136
sarathssca is offline sarathssca  India
diyAudio Member
 
Join Date: May 2014
Quote:
Originally Posted by Nelson Pass View Post
As a concept, yes. However, other characteristics aside, these Jfets are
depletion mode, so they will conveniently bias themselves up without
external circuitry. The ZVN and ZVP have to be given either a bias
voltage at the Gates (relative to their Source pins) or biased by a
current source of some kind. In this sense, it is often simply a matter
of convenience to use the Jfets.
Just checking at the option.. as here we have both n and p types of these low power mosfets available easily and at relatively lower cost.
So aside from biasing, how would they be when used in BA-3 (symmetric circuit) or LTPs (input stages) instead of the jFETs.
These MOSFET's input capacitance is higher when compared with jFETs , so do we need to go for adding cascode transistors to them?
Are there any other alternatives for depletion mode devices?
  Reply With Quote
Old 24th May 2018, 05:31 PM   #137
Nelson Pass is offline Nelson Pass  United States
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
Replacement For Toshiba 2SK170/2SJ74
Cascoding is beside the point. Enhancement-mode devices, like virtually
all the Mosfet you might encounter, require some voltage between Gate
and Source pins before they will conduct current.

For an N channel Mosfet, that voltage would be positive relative to the
Source, and for a P channel Mosfet it would be negative relative to the
Source.

Depletion mode devices want to conduct current in the absence of
Gate to Source voltage. Think of a tube. For an N channel depletion
mode device, you have to apply negative voltage between the Gate
and Source to turn the current off, just as you would have to apply
negative voltage between the Grid and Cathode of a tube to shut it
off.

For an LTP, this would not be an issue, as generally they are biased
by a constant current source attached to the two Source pins of the LTP.

For a complementary input or follower circuit, you need to come up
with some DC bias voltage or current source to put the enhancement
mode parts into conduction. Depletion mode parts often don't need this.
  Reply With Quote
Old 24th May 2018, 05:32 PM   #138
Zen Mod is online now Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Replacement For Toshiba 2SK170/2SJ74
aleph reloaded thread

see and think
__________________
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 25th May 2018, 07:11 PM   #139
juanitox is offline juanitox  France
diyAudio Member
 
juanitox's Avatar
 
Join Date: Dec 2006
i have some 2SJ109 and a cheap component tester, if it say JFET device than it"s not a fake or is there other JFets with the same case available ?
__________________
French is not a crime.
  Reply With Quote
Old 25th May 2018, 07:24 PM   #140
Zen Mod is online now Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Replacement For Toshiba 2SK170/2SJ74
I'm not aware of ....... but one never know everything
__________________
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


Replacement For Toshiba 2SK170/2SJ74Hide 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
Toshiba 2SK170/2SJ74 FET's and other semis for sale duffears Vendor's Bazaar 63 6th December 2016 01:27 PM
Swapping matched for unmatched Toshiba 2SK170 / 2SJ74 Jfets NicMac Swap Meet 4 30th October 2016 06:16 PM
2SK170 2SJ74 F-5 BOM?????? paul stewart The diyAudio Store 5 19th July 2013 07:04 AM
FS 2sj74 and 2sk170's take 2 :) Woody1911a1 Swap Meet 43 28th August 2011 09:33 PM
2sk170, 2sj74 enzedone Parts 4 21st December 2008 05:38 AM


New To Site? Need Help?

All times are GMT. The time now is 09:53 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki