Tubes in an api 500 series module

[pucho812]

Tube into hi-Z op amp which is used to drive THAT part properly, which is prob driving a 1:1 output

yes... a 1:1 jensen output

 

[Brian Roth]

I was jawboning with a friend recently on this subject. He mentioned a couple of 500 modules with toooobs (and not ones cheating with "starved plate" designs). He mentioned a Rolls module, but I don't see it after a quick search.

Bri

 

[TheJames]

I was jawboning with a friend recently on this subject. He mentioned a couple of 500 modules with toooobs (and not ones cheating with "starved plate" designs). He mentioned a Rolls module, but I don't see it after a quick search.

Bri

I think he was thinking of the Roll Music Tubule:

https://www.rollmusic.com/tubule.php

 

[Brian Roth]

Aha! In my mind I was confusing Rolls with Roll Music! Brand names too close. lol

Bri

 

[Matt Syson]

There used to be a range of 1.5 Volt heater valves available which would be very handy for 'effect' use in 500 size modules as the heater current is very small and they only had a normal 'anode' HT of 90 Volts. Finding a sufficient quantity of them would be tough now I expect.

 

[Tubetec]

I guess a 12ax7 is doable , but proper power hungry tube circuits inside a box that size ,not really ,
Hey good lookin' what you got cooking ?
I prefer my electrolytics rare ,never well done .
Somewhere in the BBC archives is a tiny matchbox sized tube preamp , runs off battery power and hearing aid valves. Might be worth a look for reference .
The DL64 and DF64 series tubes ,
http://www.r-type.org/addtext/add177.htm
For a DL64 with 15 V HT the output is 950 microwatts at 10 per cent total harmonic distortion for 0.85 V grid input and a cathode current of 184 micro-amps, probably more power in a fly beating its wings ,but thats not of any consequence if you have silicon doing the heavy lifting at the front and back end .

I second Mr Bells suggestion for making up a small switched HT board , I've found myself on the same meander in the post on battery tube mic supplies
Heres a really nicely written article by Jan Rychter ,
https://jan.rychter.com/high-voltage-power-supply-for-nixie-tube-projects

 

[iampoor1]

There used to be a range of 1.5 Volt heater valves available which would be very handy for 'effect' use in 500 size modules as the heater current is very small and they only had a normal 'anode' HT of 90 Volts. Finding a sufficient quantity of them would be tough now I expect.

I have about 300 CK6088, These might make a cool 500 series distortion tube...

https://frank.pocnet.net/sheets/138/6/6088.pdf