Grid Stopper for parallel sides of dual triode - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

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
Reply
 
Thread Tools Search this Thread
Old 23rd August 2006, 05:45 AM   #1
diyAudio Member
 
dsavitsk's Avatar
 
Join Date: Jan 2005
Location: Hartford
Default Grid Stopper for parallel sides of dual triode

If one were to use both sides of something like a 6n6p or 6n30, or 6dj8 in parallel, assuming a grid stopper is necessary, is it best to use one that connects right to the pin of one side and is a tube's width form the other grid pin, or use a seperate grid stopper on each side?
  Reply With Quote
Old 23rd August 2006, 05:53 AM   #2
diyAudio Member
 
Tubes4e4's Avatar
 
Join Date: Jul 2005
Location: Leverkusen
Citing RDH4, p571, talking about parallel class A amplifiers:

"A grid stopper should be connected directly to one or both grids. It is usually cheaper - and just as effective - to have one grid stopper of, say, 200 ohms than two stoppers each of 100 ohms."

Tom
__________________
If in doubt, just measure.
  Reply With Quote
Old 23rd August 2006, 09:00 AM   #3
diyAudio Member
 
i_should_coco's Avatar
 
Join Date: Dec 2003
Location: Surrey, UK
Just my opinion: I would use one on each. Grid stoppers need to be as close to the tube as possible to be properly effective.

Cheers,
Pete
  Reply With Quote
Old 23rd August 2006, 10:13 AM   #4
Tweeker is offline Tweeker  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Cincinnati, Ohio
Dont use a wirewound here either.
__________________
Be sure your foil hat has a good low impedance ground.
  Reply With Quote
Old 23rd August 2006, 12:01 PM   #5
diyAudio Member
 
Brian Beck's Avatar
 
Join Date: Dec 2004
Location: South Florida, USA
95% of the time, one shared grid stopper will be enough for both sections, but you might be the 5% guy. Since grid stopper resistors are dirt cheap, I would use one on each grid pin and tie the other ends together. Steve Bench went even further. He has several designs using the 417A/5842, which has four (count 'em - four) grid pins for the one section, to lower inductance. He uses four grid resistors, one for each pin. Yep, four grid stoppers for just ONE grid. Granted, the 417A is probably more of a squealer than the tubes you mentioned.
__________________
Brian
  Reply With Quote
Old 24th August 2006, 04:29 AM   #6
diyAudio Moderator Emeritus
 
ray_moth's Avatar
 
Join Date: Jan 2004
Location: Jakarta
I agree, why skimp on grid stoppers? Alan Kimmel (of mu stage fame) has stated that he uses grid stoppers wherever there is a grid - he reckons 150 ohms is a suitable value for most stages. Maybe he uses higher values for input and output stages, like most people do, I don't know.

Yet there are people who say they prefer to avoid grid stoppers wherever possible and I have never understood why.
  Reply With Quote
Old 24th August 2006, 08:57 AM   #7
diyAudio Member
 
Tubes4e4's Avatar
 
Join Date: Jul 2005
Location: Leverkusen
Hi Brian,

Quote:
Yep, four grid stoppers for just ONE grid.
I bet they are required to be connected in antiparallel, too

Tom <ducking>
__________________
If in doubt, just measure.
  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
Grid stopper resistors JoshK Tubes / Valves 2 17th March 2008 12:37 AM
grid-stopper resistor krusty75 Tubes / Valves 2 7th March 2008 12:24 AM
845 Grid stopper value Salas Tubes / Valves 6 15th February 2008 10:00 PM
Grid Stopper dsavitsk Tubes / Valves 22 18th June 2006 12:24 AM
50Hz hum after increasing grid stopper ray_moth Tubes / Valves 5 18th June 2005 04:19 AM


New To Site? Need Help?

All times are GMT. The time now is 01:30 AM.


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