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.
Figure 5. Remote Volume Control Connections
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.
Remote Volume Control Connections
Volume Control to Potentiometer CCW Leg (V)
Control to Potentiometer Wiper Leg (C)
Shield Potentiometer CW Leg (Shd)
Remote Volume
Figure 6. Remote Channel 7/8 Select Connections
CH 7/8
Select
Switch
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
Remote Channel 7/8 Select Connections
Shield (Shd)
Channel 7/8 Select (Sel)
Indicator LED Output (Ind)
CH 7/8 Select LEDs
CH 8
CH 7
10
