WhitakerAudio J C Whitaker 20 W Stereo Audio Amplifier, Руководство пользователя, Страница: 71 / 194

71
20 W Stereo Audio Amplifier
– Cut one 9-inch piece of #22 green wire and one 9-inch piece of #22 brown wire. Slip the
brown wire through the heat-shrink tubing on the lead already connected to pin 5 of V6.
Route the wire to the pin and crimp in place. Solder, keeping the heat-shrink tubing away
from the hot wires and the soldering iron. Slip the green wire through the heat-shrink
tubing on the lead already connected to pin 4 of V6. Route the wire to the pin and crimp in
place. Solder, keeping the heat-shrink tubing away from the hot wires and the soldering
iron.
– Slide the heat-shrink tubing into position at the base of the socket. Apply a stream of hot
air to shrink the tubing over the pins. Be careful to not use too much heat.
– Replace the standoff removed from the V6 socket. The screws should be finger-tight.
Remember to include the lockwasher on the component side of the board. The heater leads
should straddle the standoff.
– Twist the wires together and route to the 6V heater pads on the PWB (see Figure 5.2 d for
placement). The wires should be placed at socket-level. Do not dress the wires against the
PWB.
– Trim the wire lengths as needed to comfortably reach the pads on the foil side of the
board. Insert the green wire into the 6V heater pad adjacent to the 6VH1 post. Solder from
the component side of the board. Insert the brown wire into the 6V heater pad adjacent to
the 6VH2 post. older from the component side of the board.
– Find tubes V4, V5, and V6. Set them aside in a safe place. The tubes will be installed
during the final checkout process.
The following components should be set aside for use in building the left channel speaker
terminal PWB:
• R30 – 8.2 k
Ω
, 0.5 W
• R31, R32 – 4
Ω
, 10 W
• R33, R34 – 27
Ω
, 2 W
• R48 – 5 k
Ω
, 0.75 W, potentiometer, trimmer
• R50 – 10 k
Ω
, 0.5 W
• R68 – 270
Ω
, 2 W