The ALC6 is a combination of a speaker controller and power amplifier. The ALC units are designed to guarantee the best speaker drive, with maximum sound quality and operating reliability. The controller section consist of several stages; On the input stage the SDP circuit and on the output stage the SIS circuit ensure easy, reliable and optimised speaker response. The controller section consist of several stages; On the input stage the SDP circuit and on the output stage the SIS circuit ensure easy, reliable and optimised speaker response. The SDP circuit can be seen as the “brain” of the amplifier. By means of speaker-specific modules, that are located in 2 front-accessible slots, the characteristics of the connected speaker are loaded into the amplifier. With this, the amplifier is “tailor-made” to the speaker, regardless of the power output specifications of the amplifier. This can be done with either the analogue SDP modules, or the DDP digital drive processor™. By placing the modules in the slots, the SDP circuit is automatically activated, without the need for changing switches/jumpers (“plug&play”). Taking out the modules, bypasses the SDP circuit and converts the ALC into a “standard” stereo power ampli- fier, for use with traditional speaker systems. The SIS circuit extends the control-loop of the amplifier to the input terminals of the speaker, by means of two additional (sense) wires, compensating for the influence of speaker cables. SIS offers cable-length independent damping, resulting in a virtually infinite damping under all conditions (up to an almost immeasurable value of over 10.000). Furthermore SIS maintains signal level by detecting the amount of signal loss at the end of the cable. As a result of pre-compensation of the self-induction of the cable, non-linear harmonic + intermodulation distortion are reduced substantially by SIS, while offering a more linear frequency response (reduced linear distortion). ATCM has a number of sensors within the ampli- fier, that constantly monitor both operating temperature, in and output signal. For the temperature section of ATCM, the input signal stage is regulated when dangerous temperature increase is sensed; In this way, the amplifier stays in operation, instead of switching into “heat protection”. The Data port located on the back of the unit, is the connection for ALC remote-control function. Through the 15-pin D-connect