The APA-TOS1 is a fiber-optic audio output add-on accessory for use with an AmpPRO interface. The APA-TOS1 easily installs in your AmpPRO interface and instantly provides a digital Toslink output. APA-TOS1 is compatible with any brand and length of Toslink cable for connection into a Toslink equipped DSP, or amplifier. Benefits: APA-TOS1 provides a pure digital output for aftermarket amplifier and/or DSP installation Digital audio signals are less susceptible to noise/hiss or interference Features Quick and easy installation into any AmpPRO interface Provides digital fiber-optic variable audio signal output Compatible with Toslink equipped DSPs or amplifiers   NOTE: Toslink cable is not included