5F6A Bassman total custom build - super low output

[Dave H]

I don't think the idea is to have the star point at the input (too messy). The input is just the single point where the circuit common is connected to chassis. The star point (insulated from chassis) with the high current wires is located closer to the power supply where the current originates. The amp circuit doesn't have to be connected to chassis to function if the chassis is only a shield and not part of the circuit. The reason for not having the chassis as part of the circuit with two (or more) chassis connection to circuit common is because the transformer's stray field generates eddy currents in the chassis which cause a potential difference between the chassis ground points which is then amplified resulting in hum. Having said that I've never connected the amp common to chassis at the input. I've always made a star point at the first filter cap and made that the only connection between circuit common and chassis. Like most of us (I suspect) I've used a hybrid bus/star ground system with the bus for the preamp and star for the power amp, the only connection between circuit common and chassis being at the star.

Anyway, I'm no expert. I feel a headache coming on just thinking about it. If your grounding method works there's no reason to change it. If it ain't broke don't fix it.