The ATR-100, designed and built by AMPEX Corporation, remains one of the most popular professional analog tape recorders in use today. The ATR-100's superior audio performance can now be augmented by new technology from AUDICON DESIGN LABORATORIES.

The conventional screw-adjusted potentiometers have been replaced by digitally controlled potentiometers, or digipots. These digipots consist of a monolithic resistor ladder network with high-performance FET switches at each tap point. The desired tap point is selected by the microprocessor through a serial bus. The digipots provide an adjustment resolution of 128 steps. External scaling circuitry ensures that each step provides a resolution of 0.1 dB or better on each adjustment. The digipot is not to be confused with the Voltage Controlled Amplifier (VCA). The VCA is an active amplifier whose gain is determined by an external control voltage. VCA's can be subject to increased distortion levels. The behavior of the digipot in the signal path is essentially the same as that of a potentiometer or variable resistor.