Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

The diyAudio Store A forum for discussing anything about the products available in The diyAudio Store.

F-5 boards
F-5 boards
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 23rd April 2018, 11:29 PM   #101
hirscwi is offline hirscwi  United States
diyAudio Member
 
Join Date: Mar 2014
Location: Indianapolis, IN, USA
F-5 boards
Default Slight humm from my new F-5

Greetings, I have just finished building my F-5. The Build Guide from 6L6 was very helpful. I have it biased correctly and it sounds very nice.

I have a couple questions. I am getting a slight hum even with the volume all the way down or with the preamp disconnected. I tried to follow best practices for internal wiring: cross psu wires and input/output at 90 degrees; keep input and output wires separated, etc. I think I followed the revised grounding scheme from the thread. But obviously I've missed something. It would be great to have a couple suggestions of what to look for.

Also I wondered if there are any particular guidelines for a preamp? I am building a B1 but in the interim I am using a McIntosh C36. I wonder if this is contributing to the problem?

Attached are a couple photos. I appreciate any assistance you can provide.
Attached Images
File Type: jpg P4230006.JPG (444.9 KB, 242 views)
File Type: jpg P4230010 (1).JPG (443.5 KB, 238 views)
File Type: jpg P4230012 (1).JPG (457.5 KB, 231 views)
File Type: jpg P4230008.JPG (459.3 KB, 229 views)
  Reply With Quote
Old 21st May 2018, 02:43 AM   #102
WKCox is online now WKCox  United States
diyAudio Member
 
WKCox's Avatar
 
Join Date: Mar 2004
Location: Verona, WI
F-5 boards
Default Availability of LSJ74/LSK170 JFETs

Quote:
Originally Posted by 6L6 View Post
Didn't realize they were sold out. I'll get the ball rolling on another batch.
Have been thinking about building an F5 for about a year, but have held off due to the lack of availability of matched LSJ74/LSK170 JFETs. Any possibility of these coming back to the diyAudio Store? Any reputable alternate suppliers?

Thanks in advance for any assistance.
  Reply With Quote
Old 12th July 2018, 03:52 AM   #103
MadInventor is offline MadInventor  United States
diyAudio Member
 
Join Date: Jun 2015
Location: Iowa
Default V5T v2 or v3

Hello,

So if I understand this, the F5T boards using two outputs per rail, these can be mounted on one heat sink side, two channels per chassis. The v3 four outputs can't have two channels in one chassis (I was going to lower the bias a lot ), because it uses four output boards per channel, is this correct? The big diodes are mounted to heat sink? What idss is used on the j-fets?

Thanks,
Mad
__________________
Smoke........ahhh...crap!
  Reply With Quote
Old 15th July 2018, 11:29 PM   #104
MadInventor is offline MadInventor  United States
diyAudio Member
 
Join Date: Jun 2015
Location: Iowa
Fine, JTTAFW, have my own design now.
__________________
Smoke........ahhh...crap!
  Reply With Quote
Old 20th September 2018, 08:53 PM   #105
invaderzim is offline invaderzim  United States
diyAudio Member
 
invaderzim's Avatar
 
Join Date: Oct 2015
I just fell off the wagon and ordered the boards, parts kit and JFETs for the F5.
I was going to wait for the new SIT amp but then realized I would much more likely go "why didn't I get those JFET pairs while they were available?" rather than "why do I have so many amps to choose from?".
Plus I have nephews that are done with college and it may be time to get one or both of them into audio with a nice gift.
  Reply With Quote
Old 1st December 2018, 07:32 PM   #106
theRog is offline theRog
diyAudio Member
 
Join Date: Nov 2015
Hello hirscwi,

Just finished my F5 and experience a minor hum on the speakers when listening closely.
I guess it’s power supply ripple residue on the outputs. My power supply looks pretty identical to yours. 400VA transformer, CRC with 4 times 15000uF and 0.47R per rail.

Anyone else have this?
  Reply With Quote

Reply


F-5 boardsHide 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
F5 Turbo Circuit Boards chchyong89 Pass Labs 2404 8th October 2017 08:14 PM
F5 clone boards (inc PSU boards) Tazzz Swap Meet 39 7th June 2014 08:02 AM
FS: F5 pcb boards sonidos Swap Meet 3 13th September 2010 05:41 PM
F5 assembled boards to sell DUC985 Swap Meet 0 21st July 2009 11:17 AM
UGS Boards and F5 boards DUC985 Swap Meet 0 7th January 2009 08:21 PM


New To Site? Need Help?

All times are GMT. The time now is 01:18 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki