Squarp Instruments has pushed out firmware 3.21 for the Hapax hardware sequencer, a tightly scoped hotfix aimed squarely at the AFTR track type — the polyphonic aftertouch mode the company introduced a few weeks earlier in firmware 3.20. It's not a flashy release, but for anyone actually using Hapax's newest MPE-adjacent feature in a live or studio rig, it fixes exactly the kind of bug that makes a new feature unusable in practice.
What firmware 3.20 added
For context: version 3.20 gave Hapax a dedicated AFTR track type, built specifically for recording, playing back, and editing polyphonic aftertouch data across the sequencer. That closed one of the last real gaps in Hapax's expressive-performance story — the hardware already handled MPE zones and per-note pitch and timbre data well, but poly aftertouch had lagged behind as a first-class citizen in the sequencer's track types.
What 3.21 fixes
Firmware 3.21 addresses three issues that surfaced once musicians started putting AFTR tracks through real performances:
Channel output on Live mode. Notes played on the pads were being sent out sequentially on channel 1, then channel 2, then channel 3, rather than routing to the correct output channel — a bug that would scramble expression data for anything downstream expecting a stable per-note MPE channel assignment.
Unnecessary controller data. AFTR tracks were sending both channel aftertouch and CC74, neither of which a polyphonic aftertouch track has any use for. Squarp has stripped the PRESSURE and TIMBRE controls from AFTR tracks entirely, since they don't apply to this track type.
Stuck notes. Changing a track's type while notes were still sounding could leave notes stuck on — a small bug, but the kind that ruins a live set if it happens at the wrong moment.
Squarp describes 3.21 as a drop-in update from 3.20, with no changes to project file serialization, so existing projects and sets should load without any conversion step.
Why this matters beyond Hapax owners
Poly aftertouch and full MPE are related but distinct pieces of the expressive-MIDI puzzle, and hardware sequencers have generally been slower than software synths to treat per-note aftertouch as seriously as pitch bend or timbre. Hapax's AFTR track type — now with its rough edges sanded down — is a sign that sequencer manufacturers are treating polyphonic aftertouch as a first-class recording target rather than an afterthought bolted onto existing MIDI tracks. For anyone building a hybrid hardware-and-software MPE rig, that matters: a sequencer that mangles aftertouch channel assignment can quietly break expression on synths further down the chain without any obvious error message.
Hapax owners can grab the update through Squarp's usual firmware channel, and full release notes are available at squarp.net.