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“Baby Will” Valve Junior Conversion
Version 4
Build Manual
22 September 2009
20 of 36
7.1.6 Signal Path and Cathode Capacitors
Install, solder and trim all of the signal path and cathode capacitors as shown.
Make sure the 47uF cathode bypass capacitors are oriented with the polarities
indicated on the circuit board.
7.1.7 Hum Balance
Version 2.3 of the Baby Will circuit board is equipped with a DC elevated artificial
center tap. It uses two (2) 100 ohm 1% resistors to tie each lead of the tube
heater supply to the cathodes of the power tubes, which operate at around
10Vdc. This creates the DC elevated artificial center tap, which is a very
effective method for reducing audible hum in the amp.
Install, solder and trim the two (2) 100 ohm 1% resistors as shown below.
