OPERATION
Power Switch
The front panel switch is a master or "vacation" power switch. No matter which turn-on mode you have selected, the master power switch will turn off all cir- cuitry—including the sensing circuitry. If you will not be using the amplifier for an extended period of time, turn the master power switch "Off" (push button switch out). When you would like to return to normal operation, turn the switch "On" (push button switch in).
Power LED
The power LED indicates that the AC cord is plugged into a working AC power receptacle and that the power switch is in the "On" position.
Active LED
The rear panel turn-on mode switch determines when and how the amplifier will turn on. The "Active" LED indicates that the amplifier is operating.
Protection LED
The front panel protection LED indicates that the amplifier has been shut down because of either a fault in the wiring or the speaker, or with the SI-275 itself.
Level Adjustment Screws
The front panel level adjustment screws allow you to adjust the level of the SI-275 relative to other amplifiers in your system. Use a 1/8” slotted screwdriver to adjust the screws. If the SI-275 is the only amplifier in your system, leave the screws at their factory default position (turned fully clockwise).
Cleaning and Maintenance
The internal parts of the SI-275 are electronic and require no maintenance. Once a year it is appropriate to twist the RCA connectors on each input to remove cor- rosion and improve conductivity.
You can clean the amplifier with soft cloth or paper towel dampened with water or a mild detergent. Do not use any spray-type, abrasive cleaners on the amplifier.
