Publications

Antiderivative antialiasing with virtual IIR downsampling is applied to the generation of arbitrary piecewise linear waveforms.

The effectiveness of such an approach is only bounded by the chosen antialiasing filter characteristics.

In-depth linear response analysis of the ladder filter generalized to any number of stages.

Various alternative parameterization strategies are considered, and a low cost linear digital model that correctly reproduces the frequency response is proposed.

A new ZDF technique is proposed that is fully non-iterative, perfectly accounts for linear behavior, requires minimal topology modifications and no transformation of nonlinearities.

It is then applied to discretize a large-signal model of the ladder filter generalized to any number of stages, leading to a lightweight and high-accuracy implementation with strong stability guarantees.

Two high-accuracy and delay-free vacuum tube triode models for use in WDFs, based on a mixed physical-interpolative approach.

Tests show lower CPU usage and richer harmonic response than previous models. The algorithm is flexible enough to let the interpolation scheme be easily modified.

Simple WD opamp model, and explicit WD models of single and antiparallel diodes based on the Lambert W function.

They are usd to simulate two common guitar distortion circuits with high accuracy and minimal CPU usage.

BLEP techniques are applied to digital modeling of the sample-and-hold process inherent to BBD chips.

This results in attenuated unwanted aliasing of typical digital models while preserving the original BBD aliasing characteristics.

An experimental protocol designed to streamline audio software development and deployment is proposed.

In particular, it allows for coding, compilation, and hot reloading, each on a potentially different machine.

Simple yet precise triode model characterized by only 3 parameters that can be easily extracted from datasheets.

It can lead to non-iterative circuit models only requiring elementary mathematical functions and thus to highly-efficient implementations.

Stateful conditional branching is added to the HSDF formalism via conditionally-updating actors.

Corresponding constructs are added to the Ciaramella language without compromising its modular declarative paradigm.

Antialiasing of hard-synced sine waves is more complicated than classical geometric waveforms since it introduces discontinuities in the signal and in an infinite number of its derivatives.

A technique based on convolution with wide classes of FIR kernels is developed and is proven to be largely more effective and cost efficient than the best known method.

This paper investigates the use of frequency response compensation filters added in series to antiderivative antialiasing blocks that attenuate aliasing in static nonlinearites.

It is shown that, when using simple pole IIR kernels, such filters are stable. Therefore, it becomes possible to use such devices in recursive stateful systems without affecting their frequency response and stability.

This paper introduces the Ciaramella DSP language and its compiler named Zampogna in their first development iteration.

The peculiar properties of the language and compiler allow for easy expression and automatic static scheduling of wave digital filters.

Antiderivative antialiasing is extended to use arbitrary IIR filters for the virtual downsampling by employing partial fraction expansion and analytical or numerical integration.

Formulas are given for single and multiple, real and complex conjugate poles.

A criterion and simple formulas are found to optimally place poles and zeros when approximating fractional order lowpass filters with integer order filters.

The result can be easily extended to other fractional order filter types.

The paper suggests reformulating expressions containing the Lambert W function in terms of the Wright Omega function and provides very fast approximations.

Two application examples show the usefulness of the proposed method.

Theory of “staircase-style” waveforms and analysis of two historical synth DCOs.

Virtual analog emulation methods are also explored.

Essential references and practical advices to help DSP programmers implement efficient real-time circuit simulation algorithms.

This was an invited paper to a national conference that has a long and important tradition.

A cheap and tonally-transparent time-domain method to extend the duration of any audio signal without sounding static.

Developed to help the guys at Elk demonstrate their ELK MusicOS at NAMM 2018.

Simple and efficient implementation of both the control and audio paths, as well as their peculiar optocoupler-based interconnection.

Dynamic and nonlinear effects are accurately reproduced and stability is preserved.

Detailed derivation of a large-signal model of the ladder filter and development of a digital model that outperforms previous attempts in nonlinear behavior.

Largely made obsolete by more recent research I have conducted.

Clever yet fundamental (IMHO) addition to basic WDFs, where two new adaptors allow to easily interconnect subnetworks using different polarity and sign conventions.

They are trivial to implement, fully compatible with existing WD structures, perfect to avoid remodeling asymmetrical subnetworks, and proven to never cause stability issues.

Concise, down-to-earth, yet scientifically rigorous introduction to white-box VA modeling.

It touches on traditional circuit simulation and MNA, state-space methods, WDFs, and ZDF techniques, then details practical applications of those principles in my previous research.