5f6a grounding

[pbiagi]

Getting close to finishing 5f6a, looking forward.

Will use two star grounds - one at an input jack for preamp cathode, input jacks and tone controls, the other for everything else at power transformer.
For the negative feedback loop ground - is it better at input jack or power transformer star ground?

Paul

[MWJB]

Negative feedback loop is grounded at the presence pot, via the buss that terminates at the input jacks. Use the 59 RI/6G12-A Concert loop with a 4.7K load resistor & 25KL pot. The 5K pot set up in the 5F6A schem is noisy in operation.

Ground the PI & preamp filter caps at the input jack ground too.

[pbiagi]

Thanks. Grounded PI and preamp filters to input jack.
Will have to order a 25K pot, so will do this mod sometime soon in the future.
If I'm lucky with time, may get to finish and power the amp up today.