Doepfer A-100(~ 40 MB) - Manual (Page 227)

doepfer System A - 100 Dual Ring Modulator A-114
1
1. Introduction
Module A-114 (Dual Ring Modulator) contains two
separate ring modulators.
A ring modulator outputs the product (Multiplication X •
Y) of the signals at inputs X and Y. It’s similar to a
VCA, but whereas a VCA only responds to positive
voltages at the inputs (2-quadrant multiplication), the
ring modulator responds to both positive and negative
voltages (4-quadrant multiplication).
The ring modulator thus provides a refinement of
amplitude modulation (AM). Ordinary amplitude modu-
lation will output the original carrier frequency f
C
as
well as the two side bands (f
C
- f
M
, f
C
+ f
M
) for each of
the spectral components of the carrier and modulation
signals - but ring modulation cancels out the carrier
frequencies, and just lets the side-bands pass to the
output (see Fig. 1).
A ring modulator is used for the production of bell-like
sounds, alien voices, or just to produce new timbres.
X IN
A-114
Y IN
X • Y OUT
X IN
Y IN
X • Y OUT
RING MOD.