Operation Guide for Active Remote Volume Control
Placette pre-amps are designed to remain powered up at all times so they
do not have a power on/off switch. If your unit has a key lock on the
rear panel, this key will disable the control system, making the unit
inoperable while at the same time allowing the electronics to remain on.
The left and right channels are totally independent of each other and so
the input jacks can be located on opposite sides of the chassis as the
internal components are.
All of the I/O jacks used are durable, high quality parts that can be
cleaned often without damage. It's a good idea to do this once a month
The banana jacks on the rear panel go directly to the star-ground point
in the pre-amp and are available for use with the phono components, if
needed. The nearby chassis/lift switch is usually left in the lift
The volume is controlled by a microprocessor unit that selects various
configurations of Vishay's S-102 resistors. It is operated by the 3-way
switch on the front panel or with the remote control. The remote control
will step up or down slowly for a few steps and then speed up. The full
range of the volume control is 126 repeatable steps. These are enough
steps to make the operation less like a stepped attenuator (which it is)
and more like the gradual up and down of a conventional control. The MSB
indicator on the panel only indicates that the volume control is halfway
up and is only a warning about possible high outputs. The volume
indication with the 7 LED's on the front panel is in a binary number.
As a rough guide of the relative volume level just go by the highest LED
that is lit and ignore the ones below it.
The buffered pre-amp have a headphone jack on the front panel. When this
jack senses the presence of a headphone plug, it will switch the main
outputs off and direct the output of the class-A buffers to the
headphones. These buffers are actually small class-A power amps and are
probably the best headphone amps available today so an investment on
high quality headphones is worthwhile. Later models use the remote to
enable headphone operation.
The record mode is necessary as these units do not use a
record-out buffer because these buffers can interfere with the normal
line signals. In order to record one of the 5 source inputs, select REC
on the remote. The LED on the front panel will come on and the line
signal will be sent to the record out jack. To play a tape
machine, select the play button on the remote. This will
disconnect the source and connect the tape player. To monitor a tape
while taping, select both REC and PLAY.
Although the Vishay's S102 resistors used in this unit will have
exceptional and sparking clarity when new, they will also improve
gradually over the first few days of use. This improvement then seems to
continue over the years. Break-in can be helped along by playing
headphones for the first few days using a high quality source when the
system is not otherwise being used.
Please call 1-208-863-1089 anytime if you have a problems or questions regarding the
installation of operation of the unit.