Tube Rectifier with transformer without Center tap - Page 2 - 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 30th August 2011, 05:56 PM   #11
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
EZ81 limits are 100mA DC at 450V AC (160mA at 250V), 50uF reservoir cap, and series resistance of at least 310 ohms (150ohms at 250V). You can exceed one of these provided you keep well below the limits on the others.

100uF breaks one limit, so are you on the safe side of the others?

BTW your diagram is wrong. EZ81 has separate connections for heater and cathode.
  Reply With Quote
Old 30th August 2011, 07:55 PM   #12
diyAudio Member
 
Join Date: May 2010
Location: Ball Ground, GA
If the EZ81's filament is powered by a 6.3 volt winding that is otherwise grounded for the needs of other tubes it is powering, and if the EZ81 has a heater cathode short within it, you will definitely have glowing plates!

Dave
  Reply With Quote
Old 30th August 2011, 08:42 PM   #13
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
Good point!
  Reply With Quote
Old 31st August 2011, 02:33 AM   #14
diyAudio Member
 
Algar_emi's Avatar
 
Join Date: Oct 2002
Location: Canada, Qc
My friend will order a new tube. We will start from there.

Thanks for all your help and comments.
  Reply With Quote
Old 2nd September 2011, 02:21 PM   #15
jim is offline jim  Belgium
diyAudio Member
 
Join Date: Jan 2002
Location: Leopoldsburg - Belgium
You could try to temporarily replace the EZ81 with 2 1N4007 diodes and check if the B+ is correct then.
  Reply With Quote
Old 7th September 2011, 04:38 AM   #16
lechuck is offline lechuck  Netherlands
diyAudio Member
 
Join Date: Mar 2011
Location: Amsterdam
You stated that the EZ81 glows red when you turn it on and you have no B+ voltage. I have had the same thing one time with a 5AR4, it turned out that the filter capacitor had shorted out which caused a short circuit.

Based on my previous experience I strongly recommend you to check the power supply for any short circuits
  Reply With Quote
Old 7th September 2011, 07:24 AM   #17
diyAudio Member
 
Join Date: Nov 2002
Location: Athens, Greece
My friend first of all disconnect the amplifier from the power supply and try once more. Then if you still have the same I would suspect the 1st servoir capacitor which i would suggest to change it with a 47uf MAXIMUM. In case the problem is the EZ81 tube just try to replace it with two silicon diodes just for checking. In case you try this disconnect the rest of the circuit because the HV will be a bit higher than before.

Chris
  Reply With Quote
Old 13th November 2012, 06:52 PM   #18
diyAudio Member
 
scott17's Avatar
 
Join Date: Aug 2009
Location: JFK
Quote:
Originally Posted by kevinkr View Post
I suspect you should replace the EZ81 before going any further.. I would also add 1M/1W flame proof metal oxide resistors and 0.01uF/1kV ceramic caps across each 1N4007..
Old thread I know, but the search function on this site is amazing. I'm in the process of building an amp using a 6BY5 rectifier with an Antek toroid PT that has no center tap for the filament winding. Thanks very much for the tip.

Last edited by scott17; 13th November 2012 at 06:56 PM.
  Reply With Quote
Old 15th November 2012, 03:15 AM   #19
TheGimp is offline TheGimp  United States
diyAudio Member
 
TheGimp's Avatar
 
Join Date: Aug 2009
Location: Johnson City, TN
I hate to hijack a thread, but I don't want to start one just for this question.

Can anyone identify this full wave rectifier?

It has the same pin out as a 6X5 or 6ZY5, but the plates seem a bit large compared to the 6X5s I have. One can see all the way through the tube between the plates. There are "T" shaped heat fins that are about 1" across the top of the T and 1/4" perpendicular to it.

Tks.
Attached Images
File Type: jpg 6ZY5.JPG (142.3 KB, 243 views)
  Reply With Quote
Old 15th November 2012, 09:05 PM   #20
diyAudio Member
 
scott17's Avatar
 
Join Date: Aug 2009
Location: JFK
Could it be a 6AX5GT?

Google Image Result for http://www.radiomuseum.org/images/tubephoto_klein/6ax5gt_rca_56.jpg
  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
Rectifier options for stereo Daniels LM3875 with huge center tap transformer altie Chip Amps 4 25th May 2010 11:03 AM
dual center tap rectifier replacement dodgerblue Solid State 6 31st July 2006 05:26 PM
Transformer center tap connections Carlp Tubes / Valves 2 19th June 2006 10:01 PM
transformer with no center tap traw Parts 0 3rd June 2006 02:36 AM
Transformer Center Tap dswiston Parts 2 4th February 2004 03:09 PM


New To Site? Need Help?

All times are GMT. The time now is 12:36 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