Roland D-50 Owner's Manual page 37

2. STRUCTURE OF TONE
OUTLINE OF TONE PARAMETERS
The Ring Modulator multiplies two sounds, creating an unusual and
metallic sound that contains complicated harmonics. For instance, two
waveforms (@ and @) are multipled and waveform © is created.
This is effective for making metallic sounds.
PARAMETERS
Depending on which generators are selected in the Partial Block,
greatly different Tone Parameters will be used. Some Tone
Parameters used for the Synthesizer sound generators are irrelevant
to the PCM generator (see the diagram below).
In a Structure with Ring modulation, some parameters of Partial 2
are automatically set to those of Partial 1. See page 22 "Tone
Parameters" for a detailed explanation.