See everything your K.O. II hides.
Plug your Teenage Engineering EP-133 K.O. II into your phone or iPad and Ringside shows what the device's tiny screen can't — every pad name and setting, master FX, tempo and clock — then lets you safely change it.
How it works
plug in over USBPlug it in
Connect the K.O. II to your phone or iPad over USB-C (or a Lightning Camera Adapter). Ringside finds it and connects on its own.
See everything
The Decoder mirrors the whole project — every pad's real sample name, mode, volume, pitch, pan, choke, the faders, master FX and output compressor.
Change it safely
Edit a pad or the project and Ringside backs up first, patches the genuine device file, reads it back and verifies — never guessing, never fabricating.
Learn the hidden codes
Plain-English guides for every system setting and SHIFT code, so you never hunt through menus again.
What's inside
fully on deviceThe whole project, readable
All 48 pads with real sample names and settings, group faders, master FX, compressor and library usage — live as you press pads.
Big pads and a keyboard
Trigger the K.O. II from twelve velocity pads per group, or play it from an on-screen keyboard.
Be the clock master
Tight MIDI clock with a dial, fine steps, tap tempo and transport — or lock to the project's own tempo.
Every hidden setting explained
Plain-words guides to all the system settings, SHIFT codes and the 66 on-screen icons.
Back up and restore
Snapshot a whole project before you change a thing, restore it, or share it as a file — all stored on your device.
No accounts, no cloud
Everything happens on your device. No sign-in, no analytics, no backend. The network is only ever used for the store purchase.
Free & Pro
one-time purchaseThe whole companion
Free
- Full Decoder — see everything
- Play pads and keyboard
- Tempo and clock master
- All system guides and icons
- Audition pad edits before you commit
- Manual on-device backups
Change the device
$7.99 · one-time, no subscription
- Send pad edits to the K.O. II
- Send project & fader changes
- Save master FX settings
- Restore a backup to the device
- Two-step undo on every change
Ringside is a companion app and is not affiliated with or endorsed by Teenage Engineering. It talks to the device using the file protocol from github.com/kmorrill/ep-series-sysex (MIT licensed), credited in the app's About page.
Ringside is almost here.
Coming to the App Store and Google Play. Questions in the meantime? We're one email away.