Standard tube filament voltages and currents

ilimzn · 3rd April 2006, 07:32 PM

I'm building a sort of universal tube filament power supply. It will have a constant current and a constant voltage mode, for series and parallel filament supply, value selecvtable by a multipole rotary switch.
Now, I have already selected the constant current ranges, for most of the standard series strings:
100, 150, 300, 450 and 600mA.
The standard voltages present more of a problem. What would be the more common standard filament voltages, apart from the usual suspects, these being 1.4V/1.5V, 2.8/3V, 5V, 6.3V and 12V?
I have looked at various tube tester manuals for this, but the higher voltage ranges are usually geared towards tubes intendedfor series filament connections, which I have already covered with constant current mode operation.
Anyone care to post some additions to either the current or voltage list?

Tweeker · 3rd April 2006, 07:56 PM

20V Russian tubes such as GM70, GK71. Not all that common though.

Giaime · 3rd April 2006, 08:31 PM

Also 10V BIG ones. Think transmitting triodes...

SoNic_real_one · 4th January 2010, 04:34 AM

Look at the first letter encoding:
Tube numbering

kevinkr · 4th January 2010, 05:32 AM

7.5V for certain vintage American DHTs like the 50, and the 10(Y).

4.0V for some vintage British DHTs like the PX4 and PX25.

3.8V for vintage German DHTs like the Aa, Ba, Bas, etc..

tomchr · 4th January 2010, 06:53 AM

One suggestion: Redefine the project to be a lab power supply with adjustable output voltage. Have a mode on this power supply that turns it into a current source with a variable output current. Something like 0~30 V, 0~5 A should cover quite a bit of ground, I'd think. Add a couple panel meters showing voltage and current and you'd have yourself quite a lab supply.

I seem to recall seeing tubes with 25.2 V filaments...

~Tom

3rd April 2006, 07:32 PM	#1
ilimzn diyAudio Member Join Date: Feb 2005 Location: Zagreb	Standard tube filament voltages and currents I'm building a sort of universal tube filament power supply. It will have a constant current and a constant voltage mode, for series and parallel filament supply, value selecvtable by a multipole rotary switch. Now, I have already selected the constant current ranges, for most of the standard series strings: 100, 150, 300, 450 and 600mA. The standard voltages present more of a problem. What would be the more common standard filament voltages, apart from the usual suspects, these being 1.4V/1.5V, 2.8/3V, 5V, 6.3V and 12V? I have looked at various tube tester manuals for this, but the higher voltage ranges are usually geared towards tubes intendedfor series filament connections, which I have already covered with constant current mode operation. Anyone care to post some additions to either the current or voltage list?

3rd April 2006, 07:56 PM	#2
Tweeker diyAudio Member Join Date: Dec 2004 Location: Cincinnati, Ohio	20V Russian tubes such as GM70, GK71. Not all that common though. __________________ Be sure your foil hat has a good low impedance ground.

4th January 2010, 05:32 AM	#5
kevinkr diyAudio Moderator Join Date: Sep 2004 Location: Boston, Massachusetts Blog Entries: 6	7.5V for certain vintage American DHTs like the 50, and the 10(Y). 4.0V for some vintage British DHTs like the PX4 and PX25. 3.8V for vintage German DHTs like the Aa, Ba, Bas, etc.. __________________ www.kta-hifi.net

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Weird old power transformers (filament, SS and tube) - $7 each!	pjanda1	Swap Meet	6	29th March 2010 05:17 PM
measuring voltages and currents simple se	pforeman	Tubes / Valves	1	10th August 2009 03:38 AM
Tubelab SE input tube filament	Evenharmonics	Tubes / Valves	3	25th January 2009 01:10 AM
tube pedal plate voltages?	AmpKiller66	Tubes / Valves	3	20th May 2007 02:57 AM
ECC88 and PCC88 filament voltages	sith	Tubes / Valves	5	1st April 2004 10:30 PM

3rd April 2006, 08:31 PM	#3
Giaime diyAudio Member Join Date: Oct 2004	Also 10V BIG ones. Think transmitting triodes...

4th January 2010, 04:34 AM	#4
SoNic_real_one diyAudio Member Join Date: Jan 2008 Location: Virginia	Look at the first letter encoding: Tube numbering

4th January 2010, 06:53 AM	#6
tomchr diyAudio Member Join Date: Feb 2009 Location: Greater Seattle Area	One suggestion: Redefine the project to be a lab power supply with adjustable output voltage. Have a mode on this power supply that turns it into a current source with a variable output current. Something like 0~30 V, 0~5 A should cover quite a bit of ground, I'd think. Add a couple panel meters showing voltage and current and you'd have yourself quite a lab supply. I seem to recall seeing tubes with 25.2 V filaments... ~Tom

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read