unused secondaries on SE opt? - 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 July 2011, 04:12 PM   #1
diyAudio Member
 
Join Date: Feb 2008
Location: Niederösterreich
Default unused secondaries on SE opt?

I have searched the threads but have not found a definitive answer for my situation. A question for those more experienced; I am building again a 6BQ5 SE and using some SE opt's from a tubed Sony reel-to-reel, they are 5K with 8 ohm and 600 ohm secondaries. I have in the past just left the 600 ohm sec. floating and taped them off and grounded the black common from the 8 ohm sec. Would I benefit from terminating the unused 600 ohm sec. across a 600 ohm resistor? I don't have any test equipment anymore so I cannot test the freq. response of the transformer. TIA for the advice.
  Reply With Quote
Old 23rd July 2011, 04:40 PM   #2
diyAudio Member
 
Frank Berry's Avatar
 
Join Date: Sep 2003
Location: Midland, Michigan
You should not terminate the unused secondary.
Terminating the 600 ohm winding will reduce the amount of available power on the 8 ohm winding and will reduce the primary impedance because the transformer is double-terminated.
__________________
Frank
  Reply With Quote
Old 23rd July 2011, 05:12 PM   #3
diyAudio Member
 
Join Date: Feb 2008
Location: Niederösterreich
So I should just tape them off and not worry about it then. Thanks for the reply.
  Reply With Quote
Old 23rd July 2011, 07:12 PM   #4
diyAudio Member
 
Miles Prower's Avatar
 
Join Date: May 2005
Location: USA
Blog Entries: 6
I had the same problem: a NOS Stancor OPT that included two "tertiary" windings for whatever reason (cathode feedback, perhaps?) that I wasn't going to use. In that case, I taped 'em off, making sure that the ends were of unequal length, and tied down along with the rest of the leads. Just make sure the unused secondary(ies) won't accidentally short circuit, and you're good to go.
__________________
There are no foxes in atheistholes
www.dolphin-hsl.com
  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
OPT with foil secondaries hesener Tubes / Valves 19 9th July 2010 05:48 PM
Best way to terminate unused OPT winding? bst Tubes / Valves 6 9th October 2009 04:50 PM
2 Sowter SE15 OPT:s, unused! zix Swap Meet 1 7th August 2008 01:52 PM
Unused secondaries pilli Parts 8 7th October 2007 10:14 AM
Grounding OPT secondaries? Saurav Tubes / Valves 14 11th July 2003 08:53 PM


New To Site? Need Help?

All times are GMT. The time now is 01:27 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