1.) Yes, C30 goes to ground, at least in the Blue Stripe it does. I've scoured the PCB for days to make sure I got all the connections right
2.)I can't say I got the Rhythm 2 circuit exactly right, as some of the traces disappear underneath the relay itself (there is only one relay, BTW, but it has 2 halves), but the component values are correct. The Blue Stripe was designed with a hotter R2 channel in mind, so that 2.2M resistor (or was it 3.3M?) was subbed for 274K to feed more signal to V2A, the R2 tube/mixer.
3.) as far as the other stripes, I think just component values are different, as they all share the same board. The date stamp on mine says Copyright 1984, and the amp was made in 1988, so I can say that with confidence. Also, some components, like C30 in the lead channel, and C26 in the Graphic EQ have been removed altogether to change the sound. The problem with the Mark III is that the changes in each stripe were not documented, or publicly released, for that matter, so there's no telling what changed, and what did not, unless you spoke to Mike B, who has built/tested each one of them.
And I'll probably post an updated version. I'm planning on measuring some reference voltages sometime soon. The PT secondaries and B+ voltages have ? marks next to them because that's what the original schematic implies, or my calculations show; but then again, it comes down to that grain of salt. I need to buy a multimeter, and replace my filter caps first, as one of the 220u's has a small leak, and the others are at least 23 years old. :lol:
