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“Baby Will” Valve Junior Conversion
Version 4
Build Manual
22 September 2009
32 of 36
9.2 Power Up without Tubes
9.2.1 The First Power Up
Make sure you are working is a safe area free of any flammable
chemicals or vapors. An assembly error may result in the emission of
sparks.
The tubes should NOT be installed during the initial power up.
Plug the amplifier into a speaker cabinet. Match the speaker
impedance with the appropriate output jack. Failure to connect a
speaker will cause harm and eventual failure of the output transformer.
These measurements will NOT match those on the schematic. These
are “As-Built” measurements. The actual voltages will be measured
after the tubes are installed and the circuit draws current.
Verify the amp’s power switch is in the “OFF” position. Insert the mains power
cord in the IEC mains connector.
Secure the black ground lead of your voltmeter to the chassis star ground lug.
Switch the amp’s power switch to the “ON” position. With your voltmeter, check
the following voltages. If a significant deviation from these readings is observed,
turn off the amp, unplug the mains power and investigate.
