Teenage Engineering continues to expand what its compact $329 EP-133 KO II sampler can do, and its latest firmware release is a major one. OS 2.5 brings audio over USB, adjustable sample rates for grittier textures, sample reverse, an arpeggiator, equal-length autochopping, and a longer maximum sample time. By recording in mono rather than stereo, the KO II can now capture samples up to 40 seconds long, doubling the previous 20-second limit.
Sample reverse is such a basic sampler tool that its absence until now felt surprising, but it is a welcome addition all the same. The new arpeggiator may seem less obvious for a sampler, yet it fits the KO II especially well because of how good the device sounds when repitching audio. It gives the machine even more of that playful, Casio SK-1-style charm and makes it much easier to sketch out punchy synthpop-style basslines.
The longer sample time also pairs nicely with the new equal-length autochopping feature. The KO II’s existing transient-based chopping was already useful for slicing drum breaks into individual hits, but it was less ideal for melodic loops or more evenly structured material. This update makes the sampler far more practical for cutting up, rearranging, and reworking full phrases.
The standout feature, however, may be the selectable sample rate. Users can keep the standard 46 kHz setting, but the new 32 kHz option adds a bit of extra color, while 26 kHz pushes the sound into noticeably crunchy, digital lo-fi territory.
Those are only the headline changes. OS 2.5 also includes improved time stretching, additional scales, per-pad time shifting, and a long list of bug fixes aimed at tightening up the overall experience.
The same OS 2.5 update is available for the KO II’s reggae-themed sibling, the EP-40 Riddim. Teenage Engineering’s unusual EP-1320 Medieval sampler is also getting an update, though in a much more limited form: it only receives USB audio support. We have asked Teenage Engineering why the EP-1320 continues to miss out on many of the broader feature updates, but the company has not yet responded.
Owners can update the EP-133 KO II, EP-40 Riddim, or EP-1320 Medieval through Teenage Engineering’s update page.
