02-09-2022, 05:42 AM
(This post was last modified: 02-09-2022, 05:44 AM by Diabolical Artificer.)
Anode voltage at 170v is fine, with the screen grid at 163v it's kushti. Lot's of guitar amps don't bother with g2 de-coupling, though in hifi amps it's normal. Vg1 at 12mV is about right though it might be worth checking the grid leak resistor - 1M ? The higher values of those Erie ceramic resistors are more liable to drift high. Have you checked the cathode resistor and cap? If the former has gone high and the latter is a tad leaky Vk might be higher. Whilst most seasoned techs wouldn't change anything on the amp, mucking about and changing things does teach one a great deal.
