Eurorack Reference / modules /2hp/lpf audit site v0.1 — milestone 3
2hp/lpf

LPF

2hp

Four-pole, voltage-controlled OTA lowpass filter with 24 dB/oct slope, CV over resonance, and self-oscillation capable of 1V/oct sine VCO tracking across four octaves.341

Visualization filter_response

Capabilities 2

Lowpass Filterlowpass-filter
Four-pole OTA 24 dB/oct lowpass filter with CV over cutoff and resonance.341
Sine Wave VCO (self-oscillation)sine-vco
When resonance is at maximum the filter self-oscillates, outputting a pure sine wave with accurate 1V/oct tracking across four octaves.341

Jacks 4 — 3 in / 1 out

NameSignalVoltageDescription
Inputs (3)
FREQ CVcv-10V to 10VControl voltage input for FREQ. Added to knob position and scaled by ATTEN. Tracks 1V/oct across four octaves.341
INPUTaudio341
RES CVcv-5V to 5VControl voltage input for RES. Added to the knob position.341
Outputs (1)
OUTPUTaudio341

Parameters 3

NameTypeRangeBehavior
ATTENknobAttenuverter for the FREQ CV input. Far left accepts 0V to -10V; far right accepts 0V to 10V.341
FREQknobSets the cutoff frequency of the filter. Also known as the corner frequency or -3dB down point.341
RESknobSets the resonance (Q) of the filter. When fully clockwise the filter self-oscillates, outputting a very pure sine tone whose frequency is set by FREQ.341

Firmware history 0 versions

No firmware history recorded.

References 2

  1. [341]
    2hp LPF User Manualmanual
    verified 2026-05-14
  2. [342]
    2hp LPF product pageproduct_page
    verified 2026-05-14