Joranalogue Filter 8
8-output multimode filter and 8-phase sine oscillator
12 HP Eurorack module
Filter 8 is a 4-pole cascaded lowpass filter with 8 simultaneous outputs that excels as both a multimode filter and 8-phase sine wave oscillator. Its innovative resonant feedback circuit maintains low frequency response while adding emphasis, and at high resonance becomes a precise VCO with temperature compensation and accurate tracking across 5+ octaves.
Features
- 8 simultaneous outputs with different filter responses
- 4 lowpass poles with individual outputs
- Pole-mixing for HP, band boost/notch, phase shift, and BP responses
- Self-oscillation with 8-phase sine wave generation
- Simultaneous exponential and linear FM
- Built-in transient generator for filter pings
- Hold function for freezing filter state
- Temperature compensated VCO tracking
- Front panel V/oct and resonance calibration trimmers
Controls & Jacks (36)
- COARSE — Sets the base cutoff/resonant frequency of the filter across its full range.
- RESONANCE — Controls feedback from filter output, emphasizing filter frequency and enabling self-oscillation
- MOD. — Controls the depth of general-purpose modulation applied to the filter.
- FINE — Fine-tunes the cutoff frequency for precise pitch adjustment.
- LIN. FM — Controls the depth of linear frequency modulation for through-zero FM effects.
- EXP. FM — Controls the depth of exponential frequency modulation for musical FM timbres.
- V/Oct LED — Indicates signal presence at the V/Oct input.
- P1 Out — Phase-shifted output at the first phase angle (45 degrees).
- P2 Out — Phase-shifted output at the second phase angle (90 degrees).
- COMP. — Selects resonance compensation mode to maintain consistent output level at high Q.
- V/Oct — 1V/octave pitch tracking input for playing the filter melodically when self-oscillating.
- BP4 — Bandpass output at the fourth phase position (180 degrees), centered on the cutoff frequency.
- PING — Impulse input for exciting the filter as a resonant percussion source.
- Phase 3 Out — Phase-shifted output at the third phase angle (135 degrees).
- Signal In — Main audio input to the filter.
- 180 — Indicates activity at the 180-degree phase output.
- HOLD — Freezes the filter state, holding its current output as a static voltage.
- 135 — Indicates activity at the 135-degree phase output.
- LP1 Out — Low-pass output with a single-pole (6dB/oct) rolloff above the cutoff frequency.
- Phase 5 Out — Phase-shifted output at the fifth phase angle (225 degrees).
- BP+N Out — Bandpass plus notch combined output, useful for phaser-like timbres.
- HP Out — High-pass output that passes frequencies above the cutoff.
- AUDIO — Switches between audio-rate and sub-audio modulation behavior for the FM inputs.
- EFM — Exponential FM CV input jack for voltage-controlled frequency modulation.
- Resonance CV — CV input for voltage control of the filter resonance/Q.
- Phase 4 Out — Phase-shifted output at the fourth phase angle (180 degrees).
- LFM — Linear FM CV input jack for through-zero frequency modulation.
- BIAS — Sets the DC bias point for FM behavior, affecting modulation symmetry.
- 615 — Indicates activity at the 615-degree (equivalent 255-degree) phase output.
- 660 — Indicates activity at the 660-degree (equivalent 300-degree) phase output.
- 225 — Indicates activity at the 225-degree phase output.
- 90 — Indicates activity at the 90-degree phase output.
- 45 — Indicates activity at the 45-degree phase output.
- 270 — Indicates activity at the 270-degree phase output.
- Resonance LED — Displays the current resonance level of the filter.
- AC Coupling — Enables AC coupling to remove DC offset from the signal path.
How-To Guides
- Filter Ping Percussion
- 8-Phase Sine Wave Oscillator
- Resonating Envelopes
- Linear FM Bell Tones
- Hold Sync Bass
- Feedback Drive Distortion
- Saw Wave Oscillator
- Custom Filter Response Blending
- 8-Phase LFO Modulation
Explore the interactive Filter 8 panel on BleepDex — tap any control to learn what it does.
