alm-busy-circuits/tangle-quartet

Tangle Quartet

ALM Busy Circuits

8 HP quad linear VCA built around THAT 2164 VCA ICs. Four independent DC-coupled linear VCAs, each with its own signal input, level/CV input, and individual output, plus a summed mix output. CV inputs are normalled to +5V so each channel doubles as a manual level control, making it usable as a clean four-channel mixer as well as a VCA bank. Marketed as a no-frills, bleed-free linear VCA; reverse-polarity protected and skiff-friendly.580

Capabilities 4

Cascading Mixercascading-mixer
Each channel output is normalled to the Mix bus; patching a channel out removes it from the sum.
Mixermixer
Mix output sums all channels whose individual outputs are not patched.580
Quad VCAquad-vca
Four independent THAT-2164 linear VCA channels with a summed mix output; +5V-normalled CV inputs let each channel act as a manual level control.580
Voltage-Controlled Amplifiervca
Four independent linear VCAs using 2164 ICs, each with individual output and CV level control.580

Jacks 13 — 8 in / 5 out

NameSignalVoltageDescription
Inputs (8)
CH1 CVcvCV level input; normalled to +5V when unpatched, enabling manual amplitude control via the attenuator knob alone.580
CH1 InmixedDC-coupled signal input; accepts audio or CV signals.580
CH2 CVcvCV level input; normalled to +5V when unpatched, enabling manual amplitude control via the attenuator knob alone.580
CH2 InmixedDC-coupled signal input; accepts audio or CV signals.580
CH3 CVcvCV level input; normalled to +5V when unpatched, enabling manual amplitude control via the attenuator knob alone.580
CH3 InmixedDC-coupled signal input; accepts audio or CV signals.580
CH4 CVcvCV level input; normalled to +5V when unpatched, enabling manual amplitude control via the attenuator knob alone.580
CH4 InmixedDC-coupled signal input; accepts audio or CV signals.580
Outputs (5)
CH1 OutmixedIndividual VCA output for channel 1. When patched, this channel's signal is removed from the Mix output.580
CH2 OutmixedIndividual VCA output for channel 2. When patched, this channel's signal is removed from the Mix output.580
CH3 OutmixedIndividual VCA output for channel 3. When patched, this channel's signal is removed from the Mix output.580
CH4 OutmixedIndividual VCA output for channel 4. When patched, this channel's signal is removed from the Mix output.580
MixmixedCombined output that sums all channels whose individual outputs are not patched.580

Parameters 4

NameTypeRangeBehavior
CH1 LevelknobAttenuates the CV level input for channel 1. Fully CW with +5V CV gives unity gain; fully CCW or 0V CV gives zero output. CV above 5V amplifies the signal. The LED indicates post-attenuation CV level.580
CH2 LevelknobAttenuates the CV level input for channel 2. Fully CW with +5V CV gives unity gain; fully CCW or 0V CV gives zero output. CV above 5V amplifies the signal. The LED indicates post-attenuation CV level.580
CH3 LevelknobAttenuates the CV level input for channel 3. Fully CW with +5V CV gives unity gain; fully CCW or 0V CV gives zero output. CV above 5V amplifies the signal. The LED indicates post-attenuation CV level.580
CH4 LevelknobAttenuates the CV level input for channel 4. Fully CW with +5V CV gives unity gain; fully CCW or 0V CV gives zero output. CV above 5V amplifies the signal. The LED indicates post-attenuation CV level.580

Firmware history 0 versions

No firmware history recorded.

References 2

  1. [580]
    ALM-009 Tangle Quartet Operation Manualmanual
    verified 2026-05-21
  2. [581]
    ALM Tangle Quartet product pageproduct_page
    verified 2026-05-21