hieroglyphic/opalina
Opalina
Stereo dual-channel triple-band filter network with two switchable modes — Resonator (triple bandpass) and Isolator (cascaded state-variable) — featuring voltage-controlled frequency, span, and resonance across independent low, mid, and high bands with individual outputs and a soft-clipping SUM output.1008
Capabilities 4
- Bandpass Filterbandpass-filter
- In Resonator mode, three parallel bandpass filters with 12 dB/oct slopes and voltage-controlled peak span and resonance.1008
- State-Variable Filterstate-variable-filter
- In Isolator mode, cascaded state-variable topology with 24 dB/oct slopes and voltage-controlled mid-bandwidth and resonance.1008
- Stereo Filterstereo-filter
- Separate L and R signal paths with shared parameter controls; can be used as stereo pair or dual-mono.1008
- Vcfvcf
- Dual-channel stereo triple-band filter network; switchable between Resonator (triple bandpass) and Isolator (cascaded state-variable) topologies.1008
Jacks 16 (8 in / 8 out)
| Name | Signal | Voltage | Description |
|---|---|---|---|
| Inputs (8) | |||
| FM CV | cv | — | 1008 |
| High CV | cv | — | CV input for the high band's exponential VCA pre-filter; summed with the High slider; +5V gives approximately unity gain.1008 |
| L In | audio | — | Left (or mono) DC-coupled main input feeding all three filter bands; normalled to the R input when R is unpatched.1008 |
| Low CV | cv | — | CV input for the low band's exponential VCA pre-filter; summed with the Low slider; +5V gives approximately unity gain.1008 |
| Mid CV | cv | — | CV input for the mid band's exponential VCA pre-filter; summed with the Mid slider; +5V gives approximately unity gain.1008 |
| R In | audio | — | Right DC-coupled main input feeding all three filter bands; when unpatched, receives a copy of the L input. If only R is patched, left outputs carry no signal.1008 |
| Reso CV | cv | 0V to 5V | 1008 |
| Span CV | cv | — | 1008 |
| Outputs (8) | |||
| High Out L | audio | — | 1008 |
| High Out R | audio | — | 1008 |
| Low Out L | audio | — | 1008 |
| Low Out R | audio | — | 1008 |
| Mid Out L | audio | — | 1008 |
| Mid Out R | audio | — | 1008 |
| Sum Out L | audio | -9V to 9V | Left sum output mixing all three bands with soft-clipping; amplitude set by the band level sliders.1008 |
| Sum Out R | audio | -9V to 9V | Right sum output mixing all three bands with soft-clipping; amplitude set by the band level sliders.1008 |
Parameters 8
| Name | Type | Range | Behavior |
|---|---|---|---|
| FM | fader | — | Attenuverter for the FM CV input; scales and inverts the incoming CV signal applied to the frequency.1008 |
| Frequency | knob | 30Hz – 15000Hz | Controls the centre frequency of the mid output; range can extend beyond the panel limits via CV and the Span control.1008 |
| High | fader | — | Controls an exponential VCA pre-filter for the high band; affects both the individual high output and the sum output; +5V / fully extended gives approximately unity gain.1008 |
| Low | fader | — | Controls an exponential VCA pre-filter for the low band; affects both the individual low output and the sum output; +5V / fully extended gives approximately unity gain.1008 |
| Mid | fader | — | Controls an exponential VCA pre-filter for the mid band; affects both the individual mid output and the sum output; +5V / fully extended gives approximately unity gain.1008 |
| Mode Switch | switch | — | Selects between Resonator (triple bandpass) and Isolator (cascaded state-variable) filter topologies.1008 |
| Reso | fader | — | Controls Q (resonance) for all three filter bands; in Isolator mode the mid bandpass output has two resonant peaks.1008 |
| Span | fader | — | Behaves differently per mode: in Resonator mode controls the frequency spread of low and high bands relative to mid; in Isolator mode controls the bandwidth of the mid output, also affecting low and high cutoff frequencies.1008 |
Firmware history 0 versions
No firmware history recorded.
References 2
- [1008]
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[1009]
Hieroglyphic Opalina product pageproduct_page● verified 2026-05-28