tube measurement supply/amplifier
« on: April 03, 2006, 01:44:01 PM »

A matey who works at an audio software co has asked me to help them build a tube measuring device in order to take down properties for some dsp modelling action. The idea being to have a multichannel high voltage, high power DC coupled amp where u can plug in dif tubes to read of their stats...

Requirments are as follows:

Channel 1 (High power):
0-5V input -> 0..500V output (gain 100x) Current capacity 200 mA

Channel 2 (Medium power):
0-3.5V input -> 0..350V output (gain 100x) Current capacity 30 mA

Channel 3 (Low power):
0-5V input -> -40..10V output (gain 10x, input offset -4V) Current capacity
10 mA

Also 6.3V heater supply at 3A.

Has any if u toob gurus done anything similar or have any info for me to go on...?

Cheers  :thumb:


tube measurement supply/amplifier
« Reply #1 on: April 07, 2006, 05:49:54 PM »
A 500 volt output is a pretty tall order especially at 200mA.  You really want this much power? I suppose using power FETs you could modify a NPN only transistor design somehow. Perhaps get the gain in two stages, Elektor has a design for about 75 volts symmetrical NE5534 plus MJ350 which would be a start then take it times ten again but there is a shortage of anything silicon PNP (P channel) over about 300 volts, I want some myself! Some power amps use totem pole type outputs with transistors stacked to equalise the voltage.
Once you have cracked this one the other supplies should be simple!
Thick rubber gloves all round. Best of luck
Matt S
Matt S


Related Topics

  Subject / Started by Replies Last post
8 Replies
Last post October 08, 2004, 04:24:07 PM
2 Replies
Last post October 21, 2004, 09:27:12 AM
by dale116dot7
4 Replies
Last post September 27, 2006, 11:42:26 PM
by rafafredd
3 Replies
Last post April 02, 2007, 12:52:22 PM
by Arrigotti