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.

2sk77b
2sk77b
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 7th December 2019, 11:17 PM   #111
grimberg is offline grimberg  United States
diyAudio Member
 
grimberg's Avatar
 
Join Date: Oct 2002
Location: California, USA
Quote:
Originally Posted by Zen Mod View Post
nope
I just realized that the cryptic "nope" at the beginning of your reply means you did not specify SDIP-4 but rather 4 through-holes and I misinterpreted the PCB preview you posted. Interesting, after so many years talking to you, now I am finally starting to understand you.

  Reply With Quote
Old 7th December 2019, 11:33 PM   #112
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
2sk77b


you got it ....... 4 holes , and you can even solder those SMD ones (you mention) on them

been there , done that

pair of 2SK170BL per channel will do the job
2+2 even better

save those 389 for something demanding more Kosher parts ........

say that you have 4 pairs of 2SK170 ; JFets in pair being so-so close each to another (say 0.5mA) , while pairs being 1mA or so one from other

LTP is having two sides

one pair being A1 and A2 JFet , second pair being B1 and B2 JFet

combine A+B on one side of LTP ,leftover A+B to other side of LTP , trying to have close sum of mA on sides

hope I explained it well ......... trick used by Pa i n J2 - where he was using 2SJ109BL , two of them , but spreading JFets in one case between LTP sides , doing same with second 2SJ109BL ........ having same amount of mA Idss per LTP sides even when JFets aren't identical

Old Bull always having some tricks to teach young ones .....

anyway - same trick can be applied on two groups of JFets here , even if this isn't LTP
Attached Images
File Type: png JFet combining.png (11.5 KB, 223 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 7th December 2019, 11:51 PM   #113
grimberg is offline grimberg  United States
diyAudio Member
 
grimberg's Avatar
 
Join Date: Oct 2002
Location: California, USA
Quote:
Originally Posted by Zen Mod View Post


hope I explained it well
You did. The only thing missing is the individual Idss of each member of a pair. Should we select each JFET wih Idss around 7.5 mA to 8.0 mA, or higher?
  Reply With Quote
Old 8th December 2019, 12:40 AM   #114
grimberg is offline grimberg  United States
diyAudio Member
 
grimberg's Avatar
 
Join Date: Oct 2002
Location: California, USA
Quote:
Originally Posted by Zen Mod View Post
Old Bull always having some tricks to teach young ones...
Robert Duvall playing Officer Bob Hodges made that very clear.

  Reply With Quote
Old 8th December 2019, 10:20 AM   #115
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
2sk77b
Quote:
Originally Posted by grimberg View Post
You did. The only thing missing is the individual Idss of each member of a pair. Should we select each JFET wih Idss around 7.5 mA to 8.0 mA, or higher?
pretty much whatever you have

I chose sum current ( for 3pcs of 2SK2145BL paralleled in each section) of 20mA , arrangement I'm already using in Iron Pumpkins and SissySIT/B. M25, and that's way bellow Idss of each

so , sum current is what counts , and if you use them more , not a problem

make a list of JFets you have and I'll comment what I'll do , being in your boots
__________________
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 8th December 2019, 05:57 PM   #116
Soundhappy is offline Soundhappy  France
diyAudio Member
 
Soundhappy's Avatar
 
Join Date: Oct 2012
Location: Montpellier near Mediterranean Sea France
Thanks AnthonyA and Zen Mod for 2SK77B datasheet sharing.
BTW others SIT's have interesting similar characteristics.
Mr. Michael Rothacher " example are legendary L'Amp 2SK180
__________________
class A amplifiers with full range speakers
sings like angels in heaven
  Reply With Quote
Old 9th December 2019, 07:07 PM   #117
Soundhappy is offline Soundhappy  France
diyAudio Member
 
Soundhappy's Avatar
 
Join Date: Oct 2012
Location: Montpellier near Mediterranean Sea France
Quote:
Originally Posted by toto34 View Post
Good evening, gentlemen.
Where can we find real 2sk77b?
Thank you
Or maybe FAL Company get spare ? FAL Loudspeakers, S I T Amplifiers
Attached Images
File Type: jpg A5346421-18B5-4886-8337-F6471957F9BE.JPG (214.0 KB, 34 views)
File Type: jpg 9A16682B-8DD3-4AD5-ADD2-DD35D7204BA5.JPG (262.9 KB, 48 views)
File Type: jpg EDCA259C-BF9E-4504-B1B3-C7A9F742A317.JPG (324.0 KB, 49 views)
__________________
class A amplifiers with full range speakers
sings like angels in heaven
  Reply With Quote
Old 9th December 2019, 07:53 PM   #118
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
2sk77b
I see Cotton!

superwarm!

__________________
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


2sk77bHide 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
2sk77b and 2sk180 new projects woody Pass Labs 200 13th August 2019 10:17 PM


New To Site? Need Help?

All times are GMT. The time now is 08:00 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki