JCM 800 design question

[paulg]

I was reading the "JCM 800 love" thread and wondered what the big differences are between the 800 and earlier Plexi and metal face Mrshalls, other than the master. Any insights?

[gldtp99]

The JCM 800's V1 gain stages are cascaded (run one into the next) instead of run in parallel as in the earlier 4-input preamps---- even when jumpering channels on a 4 input the cascaded JCM 800 is capable of more preamp distortion at lower overall vol levels.
I recenly built a mostly Metro Plexi 50 clone for a guy who liked the tone, gain response when the amp was cranked up but it was "too loud" for his needs---- i converted the preamp to a JCM 800 cascaded design, added a few gain enhancing tweaks (amp still cleans up well with guitar vol down)----- now he can get the drive level he wants without pissing off his bandmates and soundmen--- He's happy, i'm happy..................gldtp99