Matched valves? How important?

[lurcher]

Indeed, but only when you switch it on

In reality a Mosfet operates on a similar principle to valves, it's voltage controlled rather than current controlled as per transistors...

I'll leave you to get back to proper valves, apologies for the interuption Dave

Its voltage controlled I agree but there the difference ends. The important feature is the electrons are not traveling in a vaccum.

This is closer to a new type of valve

http://en.wikipedia.org/wiki/Spindt_tip