APRES DIX
V.C.-MULTIBAND FILTER
MODEL : EM-401
Whereas traditional subtractive architecture tends to treat a filter as a guillotine—severing harmonics with rigid precision—APRÈS DIX functions as a dynamic acoustic resonator.
It does not merely subtract frequency content; it shapes, excites, and projects tone.
Après Dix is a high-precision voltage-controlled multiband filter designed around an active state-variable topology. Combining classical laboratory functionalism with rigorous electroacoustic engineering, it provides complete spectral control through four simultaneous response outputs: High-pass, Band-pass, Notch, and Low-pass. Where conventional subtractive architectures act as rigid spectral cutoffs, the EM-401 functions as a dynamic acoustic resonator, shaping harmonic structure with physical depth.
At the core of the circuit lie two THAT2181 Blackmer® Voltage-Controlled Amplifier ICs. Selected for their exceptionally low distortion, wide dynamic range, and minimal control voltage feedthrough, these ICs maintain clean gain staging across all filter poles. Rather than clipping harshly under heavy feedback, its dual-input topology balances automatic gain compensation with raw, unattenuated saturation. At high resonance, the signal does not choke.
As resonance approaches self-oscillation, the core expands blooming, keeping the fundamental weight intact while introducing smooth overtones around the edges. Direct voltage control over the
resonance factor via the dedicated C.V. / Q. input allows dynamic modulation of the resonance peak and bandwidth without shifting the primary cutoff frequency.
The control interface offers precise transient excitation and frequency modulation. The exponential FM input features a Depth Polarizer attenuverter for continuous sweeps between positive and negative CV polarities. When triggered at the STRIKE input, an internal fast-decay envelope circuit directly excites the core, transforming the filter into a pingable resonator capable of producing everything from tight woodblock transients to bell-like tones and deep percussive decays. Pre-filter signal mixing is managed via two independent input channels with dedicated gain controls, allowing signals to drive the processing core into variable harmonic overdrive before phase-splitting across the four outputs.
ALL RIGHTS RESERVED.
MMXXVI
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©
L.A.
CIRCUITS
CORPORATION
SONIC
DESIGN
&
ARCHITECTURE
INSTRUMENTS
resonance factor via the dedicated C.V. / Q. input allows dynamic modulation of the resonance peak and bandwidth without shifting the primary cutoff frequency.
The control interface offers precise transient excitation and frequency modulation. The exponential FM input features a Depth Polarizer attenuverter for continuous sweeps between positive and negative CV polarities. When triggered at the STRIKE input, an internal fast-decay envelope circuit directly excites the core, transforming the filter into a pingable resonator capable of producing everything from tight woodblock transients to bell-like tones and deep percussive decays. Pre-filter signal mixing is managed via two independent input channels with dedicated gain controls, allowing signals to drive the processing core into variable harmonic overdrive before phase-splitting across the four outputs.
ALL RIGHTS RESERVED.
MMXXVI
|
©
CIRCUITS
L.A.
CORPORATION
Après Dix is a high-precision voltage-controlled multiband filter designed around an active state-variable topology. Combining classical laboratory functionalism with rigorous electroacoustic engineering, it provides complete spectral control through four simultaneous response outputs: High-pass, Band-pass, Notch, and Low-pass. Where conventional subtractive architectures act as rigid spectral cutoffs, the EM-401 functions as a dynamic acoustic resonator, shaping harmonic structure with physical depth.
At the core of the circuit lie two THAT2181 Blackmer® Voltage-Controlled Amplifier ICs. Selected for their exceptionally low distortion, wide dynamic range, and minimal control voltage feedthrough, these ICs maintain clean gain staging across all filter poles. Rather than clipping harshly under heavy feedback, its dual-input topology balances automatic gain compensation with raw, unattenuated saturation. At high resonance, the signal does not choke.
As resonance approaches self-oscillation, the core expands blooming, keeping the fundamental weight intact while introducing smooth overtones around the edges. Direct voltage control over the
Whereas traditional subtractive architecture tends to treat a filter as a guillotine—severing harmonics with rigid precision—APRÈS DIX functions as a dynamic acoustic resonator.
It does not merely subtract frequency content; it shapes, excites, and projects tone.
APRÈS DIX
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