nick wrote
Since this is my gigging/cart around amp I installed some tube retainers, still needed to fit the other one in this pic.
And I want to replace the original Marshall impedence selector with one of these as apparently the original ones fall out too easily.
Need to recover the rear panel as it never came with one and I had one cut, but need to find the original Marshall tolex to make it match.
Hey Nick,
I'm intrigued by this Bass Channel/Lead channel business. Please take a hires pic of the internals and post a link.
From the reading and circuit analysing I've done, these amps, both the 1986 and 1987 versions have a Bright channel and a Normal channel. Are you referring to the Normal Channel as the Bass Channel?
As far as I've been able to understand, the difference between the Bright channel and the Normal channel in both the 1986 and 1987 circuits, is that the Bright Channel has a 500pF capacitor installed over the Bright Channel mix resistor (470k).
Then, as far as my noob understanding goes these are the primary differences between the 1986 and 1987 circuits in general:
Shared Cathode (1986)
Split Cathode (1987)
No V2a Cathode Capacitor (1986)
0.68uF V2A Cathode Capacitor (1987)
56K Tone Stack Resistor (1986)
33K Tone Stack Resistor (1987)
250pF Tone Stack Treble Capacitor (1986)
500pF Tone Stack Treble Capacitor (1987)
0.1uF Phase Invertor Coupling Caps (1986)
0.022uF Phase Invertor Coupling Caps (1987)
Is that correct? What say the experts?
