The Rolls RA170 Power Amplifier was designed especially for the installation contractor. The RA170 is a single rack-space, mono unit with a choice of an RCA or 1/4" unbalanced input. The 70 volt speaker outputs are provided via spring-loaded terminals - no transformer is required for speaker connection. The front panel includes a Power indicator LED, a Volume control and two Clip LEDs which indicate circuitry overload. The output circuitry is protected from momentary shorting and excessive load by a specially designed protective circuit.