JAN6418 and microphony

[mondogenerator]

Hi Wavebourn (or anyone with thoughts on it)
Yes, they are cheap those tubes (see below), but I'm not sure about the total cost of the project, because the JAN6418 are low voltage & can run on a 9V battery.
The ones you quoted are 60V plate, and some other Russian tubes on eBay are 165V or even more, and the power supply can end up costing more than the rest of the tube preamp, as well as being bulky (I'm using them in a guitar pedal & need it to be compact).
Do you have any thoughts on low cost compact higher voltage power supplies? Could you use a Step-Up Voltage Regulator circuit to get 60V from a 9 or 12V supply?
Thanks, John

The cons (and pros):
These tubes are absolutely great, and CHEAP, but in my experience (less than Wavebourn) they really prefer higher B+ and plate at about 90V for best distortion performance.
I have experienced very little micro phonics using them, dare I say, almost zero.

But.. they WiLL work at say 18V, 27V using 2 or 3 PP3 batteries.
The problem then is headroom in the B+.
In Pentode wiring, they may swing 8/10 of B+ (~15V p-p)
In Triode, much less, say 4V p-p, before clip.
So much depends on the magnitude of the input signal.

At low B+ it is also a challenge to obtain a grid bias, which accommodates a line level signal. It can be done with LEDs, and other ways.

1j29b I have run at 4-6mA with good results, and the weaker 1j24b, at 0.75mA with equally good results.