Roland SP-404MKII Gets Sidechain Compression in Free v5.50 Update

The Roland SP-404MKII, now running v5.50 with envelope-based sidechain compression — available as a free update for all existing owners.

Roland dropped SP-404MKII firmware v5.50 on 2 April 2026, and the headline feature is sidechain compression — something the hardware beat community has been asking for since the MKII arrived in 2021. The update is free for every existing 404 owner, and it lands right as Roland kicks off its annual 404 Day celebrations across Tokyo, Los Angeles, London and beyond.

What the sidechain compressor actually does

The implementation is envelope-based, meaning the compressor reacts directly to an audio signal rather than a separate sidechain trigger input. In practice, you assign a source pad or track and a target, set your threshold, ratio, release and gain, and the 404 handles the ducking in real time. Roland describes the result as bringing pumping, rhythmic movement to your beats — which for DnB and dubstep producers translates directly to the kind of kick-driven sub ducking and rhythmic groove shaping that sits at the core of both genres.

Sidechain compression on the 404 is particularly useful in live contexts. Many producers run the SP-404MKII as a performance sampler alongside a DAW or standalone hardware — triggering loops, one-shots, and stems on pads while mixing on the fly. Until now, getting that sidechain pump required routing audio out to an external unit or handling it upstream in a DAW. With v5.50, the whole chain stays inside the box. You can set a kick one-shot on pad 1 as the source, route your bass loop or sub pad as the target, and dial in the release to taste — all without breaking your hardware performance setup.

ExFAT and the rest of the update

Beyond sidechain compression, v5.50 adds support for the exFAT file system on SDXC cards. This is a practical quality-of-life fix — exFAT removes the 4GB file size ceiling imposed by FAT32, meaning producers working with longer stems, high-resolution audio or large sample libraries will no longer hit compatibility walls when loading cards formatted on a modern computer.

The SP-404MKII has been a consistently supported piece of hardware since launch. Roland has pushed regular firmware updates through the 5.x cycle, each adding meaningful features: Serato DJ and Studio integration arrived in v5.0, and the 404 has steadily grown from a portable resampler into a proper performance production hub. Sidechain compression is the kind of feature that confirms the 404 is genuinely built for the way underground producers actually work — not just as a nostalgia machine, but as a current tool in a modern live or studio rig.

SP-404MKII v5.50 is available now as a free download from the Roland support page. Update via SD card using the standard Roland firmware update process.