from Music thing and the New York Times:

Vacuum Tubes: Not endangered after all.

Read about Mike Matthews, who founded Electro Harmonix in 1968, and now runs New Sensor

Tubes (valves) are a big concern for any guitar tech with a tube amp, any key guy with a leslie or a sound guy with high end DI’s or processors. The process of making tubes creates some pretty toxic side products which if you have to deal with them legally in the states, makes doing business not cost effective. So most tubes are made where ecological restrictions are few; eastern Europe, Russia and China. Quality is a concern; some folks hoarde old tubes like drugs. Mike is trying to make sure that the good stuff is still made and available in the states…

yeah, it’s tweeky techy stuff but an interesting read…