WhitakerAudio J C Whitaker 20 W Stereo Audio Amplifier, Manual

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20 W Stereo Audio Amplifier
– Find varistor VR53. Place a 1-inch long piece of insulation on each lead. Use insulation
striped from a section of #18 black wire.
Metal oxide varistor (MOV) VR53 is used to prevent potentially damaging transient
disturbances on the ac line from entering the amplifier chassis. While the best location to do this is
directly across the ac input connector on the back panel, the possibility of failure of the MOV
must be considered. It is possible that following exposure to repeated high-energy surges, the
MOV could fail in a short circuit. For that reason, VR53 is connected after circuit breaker CB51.
In order to facilitate installation of this device with a minimum of lead length, it is necessary to
extend one of the leads of VR53 by a small amount, as detailed in the steps below.
– Cut a 1-inch long piece of #18 black wire. Using a soldering iron and small amount of
solder, tin one end of the #18 black wire, and tin one lead from VR53. Bring the two
tinned wires together and solder, forming a reliable solder bridge.
– Cut a 1-inch piece of small heat shrink tubing. Place over the splice point and process
(heat).
Observe the rear of the ac power connector. There are three terminals. The center terminal is
ground, as marked on the back of the device. One of the remaining terminals is the ac neutral
terminal (denoted by “ N ”) and the other is the ac hot line terminal (denoted by “ L ”).
– Using the primary ac wire included in the AC Power Connector Hardware package,
prepare a 4-inch piece of #16 green stranded wire. Attach a connector to each end of the
wire.
– Attach one end of the green wire to the ground terminal on ac input filter FL51. Connect
the other end of the wire to the ground terminal on ac power connector. It may be helpful
to use a pair of long-noise pliers to secure the connector.
– Using the primary ac wire included in the AC Power Connector Hardware package,
prepare a 4-inch piece of #16 white stranded wire. Attach a connector to one end of the
wire. On the other end of the wire, combine with the short lead from VR53 and attach a
connector (wire and lead in the same terminal).
– Attach the single-conductor end of the white wire to the neutral terminal on the ac input
filter FL51. Connect the other end (with the VR53 lead) to the neutral terminal on the ac