Sounds like: A harsh, pulsing two-tone beep like a warning siren.
A repeating, insistent two-note or pulsing tone that reads as an alarm or warning signal — simple, functional, and deliberately a little uncomfortable to sit with for long.
Open this patch in the interactive PatchpadALGO 1 gives one plain, unmodulated carrier -- no FM color needed for a functional alarm tone. MOD page 1's Square wave synced to SPD 16 pulses AMP VOL on/off in time as an alternative to just sequencing a literal repeating 2-note trig pattern -- sequencing directly is usually the more reliable of the two, but the MOD LFO route works if you want the pulse to ride a single held note. ALGO 1 routes operator A (and B) into carrier C, so LEV (A) and LEV (B) are set to 0 on SYN page 2 and MIX is -64 (the X output, C only): that leaves C a plain, unmodulated carrier.
SY RAW's plain Square wave is picked over SY SWARM here -- this patch wants a flat, functional tone, not a thick detuned stack. AMP PAGE 2's MODE must be ADSR (the default for SY machines, but drum machines default to AHD), or SUS/REL on AMP PAGE 1 are ignored. LFO PAGE 1's synced Square wave into AMP VOL gives an on/off pulse on a held note; sequencing a literal repeating trig pattern is usually simpler and just as effective.
Summit's LFO 1/2 destinations are hardwired to filter frequency and oscillator pitch, not amplitude -- reaching amplitude with an LFO needs a Mod Matrix routing whose exact menu wording isn't yet confirmed in this project's reference material, so it's left out here rather than guessed. The reliable path on this synth is simply sequencing a repeating 2-note pattern directly against a full-sustain amp envelope, which is what the square oscillator plus this envelope are set up for.
Osc 1 is 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). LFO 1 runs a Sqr wave at Sync 1/16. Mod Matrix: the LFO 1 row to the Assign 1: VCA column (hold an Assign button and turn that control to assign it) at +100. Sequencing a literal repeating 2-note pattern directly is at least as reliable as this LFO-to-amp route and needs no Mod Matrix slot at all. Values are on MiniFreak's native 0-100 scale.
M1's Square-wave LFO routed to VCA is Typhon's real mechanism for an on/off amplitude pulse on a held note. Sequencing a literal repeating pattern at the step level is usually simpler and at least as reliable if you'd rather skip the modulator slot entirely.
AMP's LFO 2 AMOUNT is a real pre-wired connection from LFO 2 -- pushing it to full lets LFO 2's synced Square wave gate amplitude on and off without needing a separate Mod Matrix routing. Sequencing a literal repeating pattern directly is a simpler, equally valid alternative.
Sequencing a literal repeating pattern is generally more reliable across all six synths than relying on an amplitude-gate LFO — use whichever mechanism each synth makes easiest.