Questions (Holden Wasp)

[TIMBO]

Hi guys, When removing the grid resistors from their position on the power tube socket the resistor's outer enamel crumbled away, they are 1/2w carbon film. They look like they were running a bit hot. I had intended to replace them with .7w metal film.
Do these resistors need to be a higher wattage?

The power tube heaters are wired in series and the unloaded voltage is around 13v. This circuit uses the chassis as a ground.
Any problems in the circuit staying like this?

When adding a PPIMV to this amp will a 250k pot/2.2m resistor work as the marshall major and wasp both have 100k grid leak resistors.

Thanks

[DummyLoad]

assuming you mean CONTROL GRID and not SCREEN grid...

high wattage not needed on control grid resistors. they likely just cooked under the sockets. use 1/2W of whatever you have on hand. 

use 1M DUAL POT || 150K Rs for the grid leaks = 110K for each phase.

2.2M || 250K = 225K is lar-mar or whatever it's called and bumps gain up a tad.


--pete