A component-accurate circuit model of a classic studio parametric equaliser — five fully overlapping parametric bands, true stereo, and the airy top end of real state-variable hardware. Free download.
The audio you hear is computed by a nodal circuit solver directly from the verified schematic of the original hardware — every resistor, capacitor, potentiometer taper and op-amp of the signal path is in the model. Turning a knob does not switch a digital filter; it literally moves the potentiometer inside the simulated circuit, with capacitor states carried over — so sweeps behave exactly like on the real desk.
100 % overlap — each band sweeps 10 Hz–20 kHz in three ranges (×0.1 / ×1 / ×10), gain +12/−15 dB, bandwidth 0.03–2 octaves. Bands grouped 1·3·5 / 2·4 to minimise interaction between neighbours.
State-variable filters with centre-tapped gain pots — at wide bandwidth the bands open up gently and musically. Pads, leads, air: this is the reason this EQ exists.
Two complete channel strips with a LINK switch — linked they act as one instrument, unlinked each side has its own EQ, filters and bypass. Mono configuration included.
High-pass 10–250 Hz and low-pass 3–40 kHz, 12 dB/oct Butterworth, built into the modelled circuit. Per-channel FLT and BYP.
Finite gain-bandwidth of the original chips (switchable to ideal) — audible as a gentle high-frequency Q-enhancement. That's the “air”.
The instrument's input receiver and cross-coupled floating output driver in the signal path (switchable), including their subtle low-end character.
1× / 2× / 4× oversampling keeps the top octave in tune. The solver auto-selects SSE2 / AVX2 / AVX-512 — the active instruction set is shown on the panel.
A resizable 19″ 2U rack panel — drag the corner to scale. Values appear when you touch a control. Portable .peqpreset SAVE/LOAD on the panel.
Tested in Bitwig, Ableton Live and Cubase.
In the works. More when it's ready.
In the works. More when it's ready.