I got a pair of unused Y-434 (version of 4X150A with gold-plated grid)
ceramic beam tetrodes for $10 from eBay. Someone told me to drive them
grounded grid, similarly to this electrostatic headphone amplifier:
http://www.headwize.com/projects/sho...lmore4_prj.htm
I found cheap sockets, but no chimneys. Is it possible to DIY chimneys?
And what's the best approach to quieting the forced air cooling blower?