On Wed, 14 Nov 2007 11:05:10 +0000, Ian Thompson-Bell wrote:

I often see volume control pots with their wiper connected directly to
the grid of the following tube. Trouble is as they wear they get a bit
scratchy and often lead to the grid becoming disconnected. Would you
agree it is good practice to add a resistor (say 1Meg) directly across
the grid?


I was taught that you should *never* allow DC on a volume or tone
control. The input to an amp should follow the sequence of resistor to
ground, isolating cap, pot, isolating cap, grid resistor to ground, grid
(or grid stopper). In light of this I've also wondered the same thing!

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info http://mixpix.batcave.net