ajh-synth/ffb-914
FFB 914 Fixed Filter Bank
Fourteen-band fixed filter bank with inductor-based gyrator circuits, stereo left/right outputs, a left-right mix crossfader, a wet-dry crossfader, and a feedback control for resonance and self-oscillation.1036
Capabilities 4
- CV-Controlled Crossfadercv-crossfader
- Two CV-controllable crossfaders: one pans between the Left and Right filter buses, the other blends between the wet filtered output and the dry/external signal. Each has a dedicated CV input and attenuator.1036
- Fixed Filter Bankfixed-filter-bank
- Fourteen gyrator-based inductor-emulation filters (12 BP + LP shelf + HP shelf) in half-octave increments from 125 Hz to 5.8 kHz, replicating the Moog 914 topology.1036
- Multiband Filtermultiband-filter
- 1036
- Stereo Mixerstereo-mixer
- Filter bands are alternately routed to Left (175 Hz, 350 Hz, 700 Hz, 1.4 kHz, 2.8 kHz, 5.6 kHz + LP) and Right (125 Hz, 250 Hz, 500 Hz, 1 kHz, 2 kHz, 4 kHz + HP) outputs, offset by a half octave.1036
Jacks 8 (4 in / 4 out)
| Name | Signal | Voltage | Description |
|---|---|---|---|
| Inputs (4) | |||
| IN 1 | audio | — | Main audio input to the fixed filter bank; normalised through IN 2 jack so the dry signal feeds the wet-dry crossfader when IN 2 is unpatched.1036 |
| IN 2 | audio | — | External audio input routed to the wet-dry crossfader; when unpatched, IN 1 dry signal is normalised here. Plugging in an external signal defeats the IN 1 normalisation.1036 |
| MIX CV | cv | 0V to 12V | CV input for the left-right crossfader; positive voltages only (negative ignored); 0–5 V gives full sweep, up to 12 V usable with attenuation via the MIX CV knob.1036 |
| WD-CV | cv | — | CV input for the wet-dry crossfader; works the same way as MIX CV with its own level attenuator (WD-CV knob).1036 |
| Outputs (4) | |||
| ALL OUT | audio | — | Combined sum of all filter bands, equivalent to the single output of the original vintage 914 Fixed Filter Bank.1036 |
| LEFT OUT | audio | — | Sum of the 175 Hz, 350 Hz, 700 Hz, 1.4 kHz, 2.8 kHz, 5.6 kHz, and Low Pass filter bands.1036 |
| MIX OUT | audio | — | Output of the wet-dry crossfader; also the source of the feedback path routed back to the module input via the FEEDBACK control.1036 |
| RIGHT OUT | audio | — | Sum of the 125 Hz, 250 Hz, 500 Hz, 1 kHz, 2 kHz, 4 kHz, and High Pass filter bands.1036 |
Parameters 7
| Name | Type | Range | Behavior |
|---|---|---|---|
| FEEDBACK | knob | — | Sets the level of positive feedback from MIX OUT back to the module input; at low settings thickens the sound, at high settings produces howling feedback or soft-clipped self-oscillation.1036 |
| IN 1 Level | knob | — | Controls the level of the filtered (wet) signal within the wet-dry crossfader mix, allowing balance between wet and dry contributions.1036 |
| IN 2 Level | knob | — | Controls the level of the dry or external signal (from IN 2) feeding into the wet-dry crossfader.1036 |
| MIX CV | knob | — | Attenuates the incoming CV voltage to the left-right crossfader; allows signals up to 12 V to be scaled for full crossfader sweep.1036 |
| OUT-MIX | knob | — | Manually pans the left-right crossfader between the Left and Right filter buses; centre position gives a 50/50 mix. Can also be driven by the MIX CV input.1036 |
| WD-CV | knob | — | Attenuates the incoming CV voltage to the wet-dry crossfader; operates the same way as the MIX CV attenuator.1036 |
| WET-DRY | knob | — | Manually pans the wet-dry crossfader between the filtered (wet) signal and the dry/external signal; centre position gives a 50/50 mix. Can also be driven by the WD-CV input.1036 |
Firmware history 0 versions
No firmware history recorded.
References 1
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[1036]
AJH Synth FFB 914 Fixed Filter Bank product pageproduct_page● verified 2026-05-29