10
External Control Connections
The SMR™821a provides a powerful external control option. This feature allows you to configure
remote controls for the Left and Right Level controls simultaneously and the Channel 7/8 select
function. The Remote operation connector provides a simple way to make these connections. Note:
Use only shielded cable. Refer to the following illustrations.
This example is used to simultaneously control the Left and Right
Level Controls from a remote location with a simple connection
on the back of the unit. A 10k pot will provide approximately 0 to
30 dB of attenuation. A 100k pot will provide about 0 to 60 dB of
attenuation. If desired‚ a control voltage can be inserted to
“command” attenuation instead of a pot. This voltage is inserted
into the “C” input and is positive referenced to SHD. Note: The
control voltage should never exceed 11 volts DC.
This example shows the connection for remote selection of the
Channels 7 or 8 input select feature. The selection is done by
connecting a momentary switch between SEL and SHD. Each time
the switch is activated‚ the channel selection is toggled and alternated
between Channel 7 and 8. This remote operation functions in
conjunction with the front panel Select Control. A bi-color LED or 2
individual LEDs may be connected as shown in the diagram for
remote indication of the selected stereo line input. Note: The IND
circuit can supply a maximum of 6 mA for the LEDs.
Remote Volume Control Connections
Remote Channel 7/8 Select Connections
Remote Volume
Volume Control to Potentiometer CCW Leg (V)
Control to Potentiometer Wiper Leg (C)
Shield Potentiometer CW Leg (Shd)
Shield (Shd)
Channel 7/8 Select (Sel)
Indicator LED Output (Ind)
CH 7/8
Select
Switch
CH 7/8 Select LEDs
CH 8
CH 7
Figure 5. Remote Volume Control Connections
Figure 6. Remote Channel 7/8 Select Connections
