Duty-Cycle Modulation

For class A tube amplifier simulation, there should be level-dependent duty-cycle modulation as a function:^10.3

• 50% at low amplitude levels (no duty-cycle modulation)
• 55-65% duty cycle at high levels

A simple method for implementing duty-cycle modulation is to offset the input to nonlinearity Eq.(9.5) by a constant, such as input RMS level times some scale factor.

---

Previous: Cabinet Filtering
Next: Vacuum Tube Modeling

Order a Hardcopy of Physical Audio Signal Processing

---

About the Author: Julius Orion Smith III
Julius Smith's background is in electrical engineering (BS Rice 1975, PhD Stanford 1983). He is presently Professor of Music and Associate Professor (by courtesy) of Electrical Engineering at Stanford's Center for Computer Research in Music and Acoustics (CCRMA), teaching courses and pursuing research related to signal processing applied to music and audio systems. See http://ccrma.stanford.edu/~jos/ for details.