Ring Modulation

Yendo Starritz

Table of Contents

General

– is a Type of Amplitude Modulation

– similar to Tremolo, but the Difference is that the Frequency of Change in Volume is in the Audible Range of Frequencies

– the Name Comes from the Actual Circuit that Creates this Effect

– Basically it Multiplies 2 Signals together, thus Creating Frequencies that are the “Sum + Difference” of the Frequencies Present in Both Signals

1) Generate a Sine Wave C4 at 261.626 (the Carrier Signal)

2) Modulate it with a Ring Modulator at G4 391.995

3) If you Blend the Signals together, once C4 (the Carrier Signal) is Fully Modulated by G4 (the Modulator Signal), “C4” will Disappear

4) In Fact both will Disappear (Original Carrier and Modulator Signals) and Neither of the 2 are Present in the Output Signal

5) The Output Signal is then simply the “Sum + Difference” of the Carrier and the Modulator Signal

Sum

391.995 + 261.626 = 653.621 Hz

Difference

391.995 – 261.626 = 130.369 Hz

– so in Our Example 130.369 (C3 -6 Cents) and 653.621 (E5 -15 Cents)

7) Or if we Take 440Hz and Ring Modulate it by 440Hz, the Sum would be 880Hz but the Difference is Zero