“Help! I need somebody! Help! Not just anybody. Help!...” Apparently these amps were popular back when this song made the charts. Probably inspired by a reluctant (Ch)amp.
Positive proof of the Principle of Entropy. Or, rather, Chaos begets Chaos. It has been whispered behind closed doors that there are people who enjoy this stuff. Not likely. Some wild stories about whole factories building stuff like this. Hmm. Unconfirmed rumours of rugged individuals who manages to, or tries to, scratch out a meager living building , fixing, working on these. Sure. I did not realise making a living from viable means is so difficult that people need to resort to this. Torture.
Not there yet, by a long shot. It gets worse by the wire. I think I have most of the turret board wires and components placed, some more wires to go to the sockets here and there, and I have altered the ground bus scheme. If it makes any difference. That big white block is the 470 Ohm resistor, why it needs to be that size, well? I have installed the 22 microFarad capacitor parallel to the 1.5 K resistor from the input jack – Pre-Amp ground (to apparently increase amp output). Note, that 1.5K resistor’s leads are too short to span the turret board anyway. More scope for dry joints. Invest in a bigger resistor.
The ground circuit will include two separate chassis (well, more, in fact, the input sockets earth too) ground points, at the power transformer for the high voltage center tap and the power amp side of things, which mixes with the pre-amp side of things through a yellow capacitor anyway, but the pre-amp side of things will ground to the chassis far away from all else, on the input socket side of things. They also act as extra earth points for this side of the circuit.
Speaking of which, I have re-measured the input resistance (“impedance”) across the input jacks, not across the earth and the lead to the valve (on the turret board side of things). According to Rob Robinette’s explanation of how this is supposed to be an elegant idea, it checks out perfectly to what he says. Still, ? If I need to plug two guitars, surely, there need only be a toggle switch adding/removing a resistor/capacitor from the one input, label this switch “High / Low”. I have seen that somewhere.
Grumble: No black wire for earth wiring in kit. Only thick wires supplied, where some thinner gauge would have helped where more than two thingabies plug into a turret pin. More colour codes would help too, to trace out the circuit’s, well, circuit.