Operation Manual

6.71 RMS 132
6.71 RMS
The RMS (Root Mean Square) module is an envelope follower. Its output is the root mean square of
the input signal. The inverse of the integration time (1/τ) is set during construction and determines
the response time of the circuit. This module has no front panel control.
amp
time
amp
time
amp
time
input signal
ouput signal
T=0.1s
output signal
T=0.01s
Figure 76: RMS value of a signal.
Typical Use
This module can be used to extract the envelope of a signal as in the following example:
Figure 77: RMS Module Used to Extract Volume.
In the example of Figure 51, Root Mean Square modules are used to make a vocoder. The
RMS modules are used to extract the envelope of different frequency bands of an audio signal from
a Player (typically a voice recording) which is then used to modulate the amplitude of correspond-
ing frequency bands in the signal from a VCO.
The default value of the following parameter is set at construction
• Cutoff frequency: Inverse of the integration time (in Hertz, values between 0.2 and 100). Sets
the response time of the circuit.