aquatank

aquaTank · effects · schema v1

4-channel feedback-delay-network (FDN) reverb / resonator. Four audio inputs feed a Hadamard mixing matrix wrapped in delay lines with per-line feedback (F1–F4), so energy recirculates and cross-mixes between the four channels — short feedback gives lush chorus/early-reflection ambience, long feedback turns it into a ringing metallic resonator. TILT skews the feedback balance across the four lines, DAMP rolls off high frequencies in the loop, CROSS sets how much the channels bleed into each other, SPREAD widens the stereo image, OUT trims level. Four direct mono outs (out1–out4) plus a summed stereo mix (mix_l / mix_r). One of the three ATLANTIS-PATCH support modules, but works standalone as a reverb, chorus, or feedback-resonance unit.

A 4-channel Hadamard feedback-delay-network (FDN) — a feedback matrix that takes four audio inputs, runs them through delay lines whose outputs are mixed back into each other through a Hadamard matrix, and recirculates them. Depending on settings it behaves as a dense reverb, a metallic resonator, a chorus, or a self-oscillating feedback-resonance instrument. Each channel has its own feedback ratio (F1..F4) and a direct out, plus there's a stereo MIX bus that spreads the four channels across the field. TILT shapes the LF/HF balance in the loop, DAMP rolls off the highs, CROSS sets how strongly channels couple through the matrix, and SPREAD/OUT shape the stereo mix. It's one of the three ATLANTIS-PATCH support modules but stands alone as a reverb/feedback box.

the faceplate

9 inputs · 6 outputs · 9 params

about this module

Hover a control, or open the patch panel and hover a jack.

inputs

id	cable	what it does
`in1`	audio	Audio input to channel 1 of the Hadamard FDN matrix. audio signal
`in2`	audio	Audio input to channel 2. audio signal
`in3`	audio	Audio input to channel 3. audio signal
`in4`	audio	Audio input to channel 4. (Patch fewer than four — empty channels still resonate via the matrix coupling.) audio signal
`fb1_cv`	cv	CV that displaces the F1 feedback-ratio knob, modulating channel 1's loop gain (resonance / decay). control voltage (CV); modulates fb1 (additive offset — ±1 CV sweeps the full range, centered on the knob)
`fb2_cv`	cv	CV that displaces the F2 knob, modulating channel 2's feedback ratio. control voltage (CV); modulates fb2 (additive offset — ±1 CV sweeps the full range, centered on the knob)
`fb3_cv`	cv	CV that displaces the F3 knob, modulating channel 3's feedback ratio. control voltage (CV); modulates fb3 (additive offset — ±1 CV sweeps the full range, centered on the knob)
`fb4_cv`	cv	CV that displaces the F4 knob, modulating channel 4's feedback ratio. control voltage (CV); modulates fb4 (additive offset — ±1 CV sweeps the full range, centered on the knob)
`tilt_cv`	cv	CV that displaces the TILT knob, modulating the LF/HF balance inside the feedback loop. control voltage (CV); modulates tilt (additive offset — ±1 CV sweeps the full range, centered on the knob)

outputs

id	cable	what it does
`out1`	audio	Channel 1's direct post-matrix output — use these four for parallel/multi-tap routing of the resonator. audio signal
`out2`	audio	Channel 2's direct post-matrix output. audio signal
`out3`	audio	Channel 3's direct post-matrix output. audio signal
`out4`	audio	Channel 4's direct post-matrix output. audio signal
`mix_l`	audio	Left side of the stereo MIX bus: out1..4 summed and panned across the field by SPREAD, scaled by OUT. audio signal; L/R stereo pair with mix_r
`mix_r`	audio	Right side of the stereo MIX bus. audio signal; L/R stereo pair with mix_l

params

id	label	range	default	curve
`fb1`	F1	0..0.95	0.4	linear
`fb2`	F2	0..0.95	0.4	linear
`fb3`	F3	0..0.95	0.4	linear
`fb4`	F4	0..0.95	0.4	linear
`tilt`	Tilt	-1..1	0	linear
`damp`	Damp	0..1	0.4	linear
`crossMix`	Cross	0..1	0.5	linear
`spread`	Sprd	0..1	0.7	linear
`outLevel`	Out	0..1	0.6	linear

controls

control	what it does
Cross	Inter-channel matrix coupling (0..1): how strongly the four channels feed into each other through the Hadamard mix. Low keeps channels independent (parallel combs); high binds them into a dense, diffuse reverb.
Damp	High-frequency damping inside the matrix (0..1): higher values bleed off the highs each pass, taming harshness and shortening bright resonances.
F1	Channel 1 feedback ratio (0..0.95): how much of the loop recirculates. Low = short decay / subtle ambience; near 0.95 = long ringing resonance approaching self-oscillation.
F2	Channel 2 feedback ratio (0..0.95).
F3	Channel 3 feedback ratio (0..0.95).
F4	Channel 4 feedback ratio (0..0.95).
Out	Output gain of the stereo MIX bus (0..1). The direct out1..4 taps are unaffected by this.
Sprd	Per-channel stereo-pan width on the MIX bus (0..1): 0 collapses the four channels to center, 1 spreads them wide across the stereo field.
Tilt	LF/HF balance in the loop (-1..+1): negative tilts the recirculating energy toward the lows (darker, boomier resonance), positive toward the highs (brighter, more metallic).

source

aquatank.ts on GitHub.