120w valve amplifier.

[Murphyv310]

Single point grounding is the way to go. On big amps the busbar should be thicker than 16 gauge. I use old wire coat hangers in all my amps, ground the busbar at the input only. I also make an HT busbar which makes for neatness and helps to reduce any tendency of instability. Always decouple smoothing caps with a small value too, again often overlooked.
I must admit I've not looked at the thread for a while too.