Sounds like: A pad that starts dark and slowly opens over several seconds.
A textbook slow filter sweep — the note starts dark and closed, then opens gradually over several seconds. Simple, effective, and one of the most fundamental pad movements in electronic music.
Open this patch in the interactive PatchpadDigitone II's ALGO 3 gives three plain carriers (C, B2, B1) when the FM depth of A and B is off, so LEV (A) and LEV (B) are both 0. MIX -64 selects the X tap (C + B2), and DTUN, which offsets only the ratio of operators A and B2, detunes B2 against C so the two beat against each other. DTUN below 64 is a very slight detune; above 64 is heavier. The AMP page's instant ATK with full SUS means loudness carries no movement at all -- the entire sweep is the FLTR page's own envelope, whose ATK is set to 127 (the maximum, several seconds) with FREQ starting at 0 and a strong positive ENV of 100 so the cutoff climbs the full range as the filter envelope rises. MODE on the AMP page must be ADSR so the amp actually holds at SUS rather than reverting to AHD shape.
AMP PAGE 2's MODE must be ADSR (the default for SY machines, but drum machines default to AHD), or the sustain doesn't hold.
FILTER's SOURCE is set to Mod Env 1 rather than Amp Env specifically so the sweep can have its own several-seconds-long ATTACK (127, the maximum on Summit's exponential time curve) independent of the Amp Envelope, which stays instant-on with full sustain throughout. This SOURCE routing is the real mechanism Summit uses in place of a dedicated filter-envelope section.
Osc 1 and Osc 2 are BasicWaves with Morph at 50 (pure sawtooth): the Morph knob runs from a square (0) through a sawtooth (50) to a double sawtooth an octave up (100), Sym only changes the pulse width below 50, and Sub adds a sine an octave down (0 here). Mod Matrix: the CycEnv row to the Cutoff column at +85. The classic slow-open sweep needs an instant amp but a several-second filter open -- since MiniFreak's single Envelope is hardwired to the VCA, the slow filter movement comes from the separate Cycling Envelope (one-shot Env mode, slow Rise of 90) routed via the Modulation Matrix, rather than from the amp Envelope's own Env/Velo knob. Values are on MiniFreak's native 0-100 scale.
FILTER TIME turned to its slowest position multiplies the already-maxed FILTER ADSR ATTACK (100) into the longest sweep Typhon can produce -- but Typhon's maximum envelope times are shorter than the other five synths, so expect a noticeably faster-resolving sweep even at these extremes; compensate by triggering the note a beat or two earlier than you would on the other synths. AMP TIME turned fast keeps the Amp ADSR's own instant-on, full-sustain shape from adding any competing movement.
ENVELOPE 1 is pre-wired to Filter 1 -- its real 4000ms ATTACK (Hydrasynth's envelopes are genuine milliseconds, not a raw 0-127 curve) with a strong positive ENV 1 AMOUNT is what drives the several-seconds-long open. ENVELOPE 2 (pre-wired to Amp) stays instant-on with full sustain throughout, so loudness itself carries no movement.
This patch lives or dies on the filter envelope's attack time being genuinely long — a few seconds minimum. Check each synth's maximum attack time; some hardware envelopes cap out shorter than this patch ideally wants.