Search found 2 matches

by pup tentacle
Wed Feb 26, 2014 8:07 pm
Forum: Marshall Discussion
Topic: ok to use 1 ohm res from pin 8 for bias chk JCM MK2
Replies: 4
Views: 1364

Re: ok to use 1 ohm res from pin 8 for bias chk JCM MK2

The prints I have seen show a 320uf with an 820 ohm resistor across it. It seems a pretty radical change to go to .67uf.
by pup tentacle
Wed Feb 26, 2014 1:18 pm
Forum: Marshall Discussion
Topic: ok to use 1 ohm res from pin 8 for bias chk JCM MK2
Replies: 4
Views: 1364

ok to use 1 ohm res from pin 8 for bias chk JCM MK2

Just wondering if it's acceptable practice to install 1 ohm resistors between cathode and ground on the 6550's in a 1974 JCM 50 watt amp. Not all that familiar with the Marshall amps and these tubes. On this same amp someone had replaced the first pre amp tube bypass cap with 1uf and 2uf electrolyti...