#26 line stage help - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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
Thread Tools Search this Thread
Old 5th July 2004, 04:22 PM   #1
diyAudio Member
Join Date: Nov 2002
Default #26 line stage help

Ok I have finally gotten around to playing with the #26 again. I have B+ of 306V, plate resistor value of 43K, plate voltage of 133v. I have 10.0v across my 2.5K cathode resistor. I have a cathode by pass of 1000mfd. I am using a 2.0V 5AH battery with a .47 dropping resistor to end with 1.5V. If I understand the tech sheet correctly I should be ballpark and it should be ok.

The main problem still seems to be some small hum that seems to lower in level when I touch the chassis. Any thoughts on how to totally kick the hum to the curb? Now, I have read about every article I could find on the 26 and the hum problems and I thought the hum might go away using the battery for the heater feed. Any thoughts/comments? Thanks for the help in advance.

  Reply With Quote
Old 6th July 2004, 11:48 PM   #2
diyAudio Member
Join Date: Nov 2002
  Reply With Quote
Old 7th July 2004, 12:46 AM   #3
pedroskova's Avatar
Join Date: Dec 2002
Location: C'ville VA, USA
Sounds like ground loop hum. Does it hum with no source connected? Have you tried running a ground wire between preamp chassis and amp chassis?
  Reply With Quote
Old 7th July 2004, 10:46 AM   #4
diyAudio Member
Join Date: Nov 2002
Thank you for your reply. I will try grounding the line stage to the amp tonight and see if it makes a difference in the hum. I will also try it without an input and with the input shorted.

  Reply With Quote
Old 9th July 2004, 10:56 AM   #5
diyAudio Member
Join Date: Nov 2002
I tried it and it didn't help.
  Reply With Quote


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
Which DHT for Line stage? andyjevans Tubes / Valves 15 26th March 2009 01:10 PM
Aikido line stage - plus phono line stage cjkpkg Tubes / Valves 1 22nd November 2008 09:50 PM
Line stage preamp, based on SY's "Heretical Unity gain line stage" Danko Tubes / Valves 23 18th July 2005 04:07 AM
Line stage woody Tubes / Valves 5 10th August 2003 08:55 PM
Foreplay Line Stage Pre-amp vsr123 Pass Labs 4 21st May 2003 03:30 PM

New To Site? Need Help?

All times are GMT. The time now is 02:33 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2