Uploaded December 2024 | Updated September 2026, 3 hours ago
Opto Phase is an analog-modeled phaser effect, based on a custom-designed phaser circuit. The phaser circuit functions using a light-source (e.g. an LED) driven by a low-frequency oscillator (LFO), which is then coupled to a series of light-dependent resistors, which in turn control the cutoff frequencies for a set of allpass filters, thereby creating a modulating "phasing" effect.
In this effect, the dynamics of the opto-couplers are modeled using a physically-informed differential equation solver, while the rest of the circuit is modeled using Modified Nodal Analysis. The "Rate" knob controls the speed of the LFO driving the phaser effect.
The "Feedback" knob controls the amount of signal being fed-back from the output of the effect back into the phaser circuit.
The "Frequency" knob controls the "base" cutoff frequency for the allpass filters, and the "Range" knob controls how far the cutoff frequencies are allowed to be modulated.
The "Stages" knob controls how many allpass phasing stages are in the circuit. A 2-stage phaser corresponds to a "45 degree" phase shift, 4 stages corresponds to 90 degrees, and so on.
Chowdhury DSP is a boutique audio software creator with the goal of developing high-quality, innovative audio effects and other tools for musicians and music producers.
Get Opto Phase now:
chaosaudio.com/collections/tone-shop/products/opto-phase
Available on the Stratus® multi-effects pedal:
chaosaudio.com/products/stratus
Stratus® CPU: 7.2% - 8.8%
Opto Phase is an analog-modeled phaser effect, based on a custom-designed phaser circuit. The phaser circuit functions using a light-source (e.g. an LED) driven by a low-frequency oscillator (LFO), which is then coupled to a series of light-dependent resistors, which in turn control the cutoff frequencies for a set of allpass filters, thereby creating a modulating "phasing" effect.
In this effect, the dynamics of the opto-couplers are modeled using a physically-informed differential equation solver, while the rest of the circuit is modeled using Modified Nodal Analysis. The "Rate" knob controls the speed of the LFO driving the phaser effect.
The "Feedback" knob controls the amount of signal being fed-back from the output of the effect back into the phaser circuit.
The "Frequency" knob controls the "base" cutoff frequency for the allpass filters, and the "Range" knob controls how far the cutoff frequencies are allowed to be modulated.
The "Stages" knob controls how many allpass phasing stages are in the circuit. A 2-stage phaser corresponds to a "45 degree" phase shift, 4 stages corresponds to 90 degrees, and so on.
Chowdhury DSP is a boutique audio software creator with the goal of developing high-quality, innovative audio effects and other tools for musicians and music producers.
Get Opto Phase now:
chaosaudio.com/collections/tone-shop/products/opto-phase
Available on the Stratus® multi-effects pedal:
chaosaudio.com/products/stratus
Stratus® CPU: 7.2% - 8.8%
