Frap Tools Intros Brenso Entangled Sound Sources

Frap Tools has introduced the BRENSO, described as their ‘primary analog source of articulated waveforms whose degree of entanglement can be precisely set by the musician’.

Here’s what they have to say about it:

“Its concept developed from a reflection on the very meaning of the word ‘complex,’ which comes from the Latin verb plector, literally meaning ‘to weave.’

The purpose of BRENSO is to update the usual approach to ‘complex oscillator’ by offering many threads to be woven together, rather than a pre-defined weft of controls and waveforms: this to improve clarity, manageability, and to provide more sonic options to the artist.”

BRENSO consists of three sections: two for the sound generation (yellow and green), and one for sound processing (white and red).

The generation sections allow control over the two triangle-core oscillators, which can be modulated and synced both internally and externally. The Frequency Modulation can be any combination of exponential and/or linear through-zero.

The processing section is composed of a Timbre Modulation section (white) and a final stage of Amplitude Modulation (red). The Timbre Modulation contains two parallel waveshapers with a PWM circuit, which are mixed with a crossfader and processed by a wavefolder. The wavefolder has symmetry control and can be pinged through a dedicated clock input with a shapeable, nonlinear behavior.

A four-quadrant multiplier further modulates the timbre-modulated sound with the green oscillator’s sine wave: it can perform Amplitude Modulation or Ring Modulation, and a crossfader defines the balance between the modulated and unmodulated signal.

The Timbre section CV inputs are semi-normalled to a Timbre Modulation Bus, which is, in turn, semi-normalled to the green sine wave. Many other modulation destinations are semi-normalled to the other oscillator’s sine wave, with attenuverters and attenuators to guarantee precise control. All the semi-normalizations can be ‘broken’ anywhere throughout the signal routing according to the musician’s needs.


  • Two analog ‘thru-zero’ triangle-core oscillators
  • Coarse frequency lock function per oscillator
  • Eight waveform outputs, four per oscillator
  • Linear ‘Thru-Zero’ Frequency Modulation (TZFM)
  • Independently mixable Linear and Exponential FM per oscillator
  • Flip Sync (the green oscillator can be sync’ed to the yellow one)
  • Lock Sync on both oscillators
  • Balanced or unbalanced modulation (AM / RM)
  • Original timbre shaping section
  • Explicit signal flow

Pricing and Availability

The Frap Tools Brenso is available now for 639 EUR/USD.

5 thoughts on “Frap Tools Intros Brenso Entangled Sound Sources

    1. is it really a contest? does another module need to be invented in response to one manufacturer releasing their own

  1. Is there a compressor over the bresno output? If true please remove it so we can listen to the dynamics of the osc as well.

  2. The more I work with, read about and listen to Frap Tools’ modules the more I want to build a dedicated case to just their modules. I had my eye on another complex oscillator but I might switch it up for this instead.

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