Teenage Engineering has already issued multiple substantial updates for its surprisingly capable $329 EP-133 KO II sampler. Its latest is one of the biggest yet. OS 2.5 adds audio over USB, selectable sample rates for lo-fi fun, sample reverse, an arpeggiator, equal-length autochopping, and it extends the maximum length of a sample from 20 seconds to 40 seconds by capturing mono, instead of stereo, audio.

Sample reverse is such a simple feature that it’s shocking it wasn’t implemented earlier. An arpeggiator doesn’t always make a ton of sense on a sampler, but the KO II sounds so incredible repitching samples (like the SK-1 successor I’ve always wanted) that here it’s a huge addition. It’s easier than ever now to crank out a synthpop bassline.

The combination of longer sampling time and equal-length autochopping also makes the KO II much better suited to chopping up and rearranging samples and loops. While the transient-based autochopper was great for isolating drum hits in a break, it was less useful for melodic content.

My favorite new feature, though, is the new selectable sample rate. You can stick with the standard 46k kHz if you want, but the new 32 kHz mode adds some nice character, while 26 kHz goes full lo-fi, turning crunchy and digital.

Those are just the headlining features. There’s also improved time stretching, new scales, per-pad time shifting, and tons of bug fixes.

The OS 2.5 update is also available for the KO II’s reggae-themed sibling, the Riddim. While the bizarre EP-1320 Medieval sampler is finally getting an OS update, it’s only getting USB audio, and nothing else. We’ve asked Teenage Engineering why the EP-1320 is regularly left out of the update fun, but have yet to hear back.

You can update your OP-133 KO II, EP-40 Riddom, or EP-1320 Medieval here.