13FD7 'Mini Williamson'

 

 

 

 

Schematic Notes :

HV power switch also switches filament transformer.

RC filters on amplifier schematic are a ghost copy of the HV supply filters, which are common to both channels

Both 8 and 4 ohm OPT taps are brought to external terminal block.

MJE340s heatsinked to side wall.

V1AA/V2AA are long tail paired vs. not in the original Williamson.

100k grid stoppers form HF filter for loop stability with T7010 OPT.

 

Inside view with Power Supply/Heaters wired

and Current Mirror side boards assembled.

 

Inside View - Fully Wired

 

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