Analogue Systems


Ring mod + multiple

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

In use :


The RS-20 incorporates a high quality AC-coupled ring modulator that sounds somewhat different to the RMs in synthesisers such as the ARP2600, Roland System 100M, and EMS VCS3. This is because these three instruments (and many others) use the same ring modulator chip: the LM1496.

The RS-20 is an altogether different design that offers accurate ring modulation over a wider range of frequencies and amplitudes. It offers two inputs and one output. There are no controls. 

  • X-IN:

    Accepts any signal with maximum amplitude ±10V.   

  • Y-IN:

    Accepts any signal with maximum amplitude ±10V. 

  • OUT:

    Outputs the results of AC-coupled ring modulation. The new signal will have a maximum amplitude of ±10V. 



  • Multiple:

    The RS-20 also incorporates a passive "multiple" with four interconnected input/output sockets. These are hard-wired together and may be used to distribute any audio signal or CV to multiple destinations. 

    This multiple may be used as a simple mixer with unity gain.

Analogue Systems

Custom vintage analogue synthesiser system equipment.