Juma's LSK Preamp - through hole version - diyAudio
Go Back   Home > Forums > Commercial Sector > Group Buys

Group Buys Members group buys

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 11th January 2014, 04:45 PM   #1
diyAudio Member
 
prasimix's Avatar
 
Join Date: Feb 2009
Default Juma's LSK Preamp - through hole version

This thread is for anyone interesting in building Juma's JFET preamplifier presented here.

I prepared two versions of PCB: with power supply for two or one channel. We should decide which PCB to use or we can go with two GB if price is acceptable. Both version can host 2SK24/2SJ103 or 2SK170V/2SJ74V (check in BOM).

Please find in attachment the latest schematic, PCB layout and BOM for both version.

EDIT: Please note that both layout is now obsolete. Improved version can be found in most recent posts. Group buy list with prices are available here.

EDIT2: PCB can be also used for Phase splitter menitoned here.
Attached Images
File Type: png Juma preamp rev.2.1 dual schematic.png (124.6 KB, 1465 views)
File Type: png Juma preamp rev.2.1 dual.png (176.5 KB, 1417 views)
File Type: png Juma preamp rev.2.2 single schematic.png (86.7 KB, 1382 views)
File Type: png Juma preamp rev.2.2 single.png (127.7 KB, 1309 views)
Attached Files
File Type: pdf Juma preamp rev.2.1 dual BOM.pdf (49.9 KB, 108 views)
File Type: pdf Juma preamp rev.2.2 single BOM.pdf (48.7 KB, 90 views)

Last edited by prasimix; 26th January 2014 at 12:45 PM.
  Reply With Quote
Old 11th January 2014, 06:20 PM   #2
Ryssen is offline Ryssen  Sweden
diyAudio Member
 
Ryssen's Avatar
 
Join Date: Dec 2003
Location: Sweden--> Here
AsI said before I´m in for the Dual (Stereo) verision,but can allso be interessted in the singleverision depending on others choise..
__________________
Regards Åke
  Reply With Quote
Old 11th January 2014, 09:02 PM   #3
BigE is offline BigE  Canada
diyAudio Member
 
Join Date: Aug 2008
Location: Toronto
I'd be interested in the LSK circuit board *only* with no power supply section.
  Reply With Quote
Old 12th January 2014, 02:59 AM   #4
diyAudio Member
 
Join Date: Oct 2001
Location: .
please count me 4 stereo sets of both version if possible
  Reply With Quote
Old 12th January 2014, 09:23 AM   #5
diyAudio Member
 
prasimix's Avatar
 
Join Date: Feb 2009
Quote:
Originally Posted by BigE View Post
I'd be interested in the LSK circuit board *only* with no power supply section.
Hm, that complicate a whole thing. I tried to make another layout where you can simply cut PS section if you do not require it. For DC power you can use J4 connector. Unfortunatelly this introduce 3 additional position for resistors (R10A, R13A and R23A) and one jumper just below C7.

I will go with this solution if other members which is already shown interest for solution with PS do not have a problem with such approach.
Attached Images
File Type: png Juma preamp rev.2.3a single.png (138.0 KB, 1171 views)
  Reply With Quote
Old 12th January 2014, 09:26 AM   #6
diyAudio Member
 
prasimix's Avatar
 
Join Date: Feb 2009
Quote:
Originally Posted by arthur View Post
please count me 4 stereo sets of both version if possible
Ok, if I understood you correctly you are interested in 8 x single and 4 x dual PCB?

Please also let me know your destination that I can ask for shipment cost.
  Reply With Quote
Old 12th January 2014, 09:43 AM   #7
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
could it be made 'break-off' at the shown dotted line ?
and with solder pads for connect jumpers, if used without breaking
__________________
sometimes we know very little, and sometimes we know too much
  Reply With Quote
Old 12th January 2014, 09:52 AM   #8
Ryssen is offline Ryssen  Sweden
diyAudio Member
 
Ryssen's Avatar
 
Join Date: Dec 2003
Location: Sweden--> Here
What trafo is to be used,volts and VA?
__________________
Regards Åke
  Reply With Quote
Old 12th January 2014, 10:26 AM   #9
diyAudio Member
 
prasimix's Avatar
 
Join Date: Feb 2009
Quote:
Originally Posted by Ryssen View Post
What trafo is to be used,volts and VA?
Juma used 10VA, check this post.
  Reply With Quote
Old 12th January 2014, 11:22 AM   #10
diyAudio Member
 
prasimix's Avatar
 
Join Date: Feb 2009
Quote:
Originally Posted by tinitus View Post
could it be made 'break-off' at the shown dotted line ?
and with solder pads for connect jumpers, if used without breaking
I don't like to introduce jumpers if they are not really necessary. Here I can add perforation to make cutting job even more straightforward. Learned from some other project such perforation will not jeopardize mechanical strength of the board.
Attached Images
File Type: png Juma preamp rev.2.3b single.png (135.2 KB, 273 views)
  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
Juma's LSK Preamp - SMD version buzzforb Group Buys 175 Today 01:18 AM
Juma's Preamp for F5 -new built- GentryBa Pass Labs 31 2nd February 2013 12:19 PM
26 Preamp, Kennedy Version 3 GTHICM Tubes / Valves 13 9th December 2009 02:00 AM
My version of a Slone preamp gain Solid State 12 16th October 2008 08:05 PM


New To Site? Need Help?

All times are GMT. The time now is 06:44 PM.


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