The RS-20 contains two independent modules: a high quality ring modulator, and a four-part multiple.
This module contains an analog high-quality ring modulator and an 1x4 multiples.
AC-coupled ring modulator, based around the AD633 multiplier IC.
The original frequencies are suppressed and you can hear only the sum of the frequencies (X+Y) and the difference (X-Y). The ring modulator works very clean. If only one signal is connected you won´t hear anything at the output. That is not the case with most ring mods as often you hear a bleed thru