Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki 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

heater voltage
heater voltage
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 16th November 2008, 08:03 PM   #1
Jaap is offline Jaap  Netherlands
diyAudio Member
Jaap's Avatar
Join Date: Dec 2002
Location: Netherlands
Default heater voltage

I have a transformer with 5V/2A.
I need to feed two 807 tubes (6,3V/0,9A each)

Is it useful/possible to rectify the 5V and will it deliver enough volts/current for the tubes in this way ?
  Reply With Quote
Old 16th November 2008, 08:48 PM   #2
simplicisius is offline simplicisius  Serbia
diyAudio Member
Join Date: Nov 2008
you simply dont have enough power in trafo. need 11.34W, and you have only 10W.
  Reply With Quote
Old 18th November 2008, 10:05 PM   #3
46davis is offline 46davis  United States
diyAudio Member
Join Date: Nov 2008
I tried what you're thinking with a couple of current hog 5687s. What I didn't figure on was the more than 1v forward current drop in the big bridge rectifier that more than ate up all the p-p benefit I was hoping to get. Sorry, won't work.
It IS ok to suck a little more than rated current from a heater winding of a p trans if you're not using another of the windings, like the 5v rectifier heater winding.
  Reply With Quote
Old 18th November 2008, 11:39 PM   #4
Tom Bavis is offline Tom Bavis
diyAudio Member
Tom Bavis's Avatar
Join Date: Jun 2002
Location: Macedon NY
A bridge and boost regulator can give you 6.3V... but not 1.8A - as mentioned, there isn't enough transformer.
  Reply With Quote


heater voltageHide 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
DC Heater Voltage Bengali Tubes / Valves 9 2nd February 2009 04:19 AM
Too low heater voltage? jkeny Tubes / Valves 6 26th August 2008 12:08 AM
Need Help Setting Heater Voltage cgrums Tubes / Valves 10 25th January 2008 05:40 PM
DHT heater voltage zobsky Tubes / Valves 23 9th September 2006 03:55 PM
heater voltage: why ac, and not dc? alex278 Tubes / Valves 18 7th October 2005 12:21 PM

New To Site? Need Help?

All times are GMT. The time now is 04:38 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio