The Brenso utilizes a dual-oscillator architecture where one generator serves as a modulator for the other. To streamline patch creation, the module incorporates internal semi-normalizations, automatically routing the sine wave of one voltage-controlled oscillator (VCO) to both the linear and exponential frequency modulation (FM) inputs of the opposing VCO. Both oscillator sections provide exponential and linear Thru-Zero FM inputs, which feature individual attenuators and a shared FM deviation parameter that regulates the overall modulation depth.

The timbre-shaping section consists of independent waveshapers for the triangle and square waveforms. These signals can be blended and routed into an analog wavefolder stage. The wavefolder features a dedicated trigger input connected to an internal decay envelope, allowing the circuit to be "pinged" for transient-rich percussive tones. From the wavefolder, the audio passes through an integrated voltage-controlled amplifier (VCA) that can be toggled between two-quadrant mode for traditional amplitude modulation and four-quadrant mode for ring modulation. For live performance reliability, each oscillator features a coarse frequency lock button that disables the main pitch potentiometer, leaving only the fine-tuning control active.