How to Fit More Samples on Your EP-133 K.O. II (the 128 MB Limit)
The EP-133 K.O. II holds 128 MB of samples across 999 slots. When you start running out, you don't have to delete sounds, you can optimise them. Here's how to fit more onto the device with the Batch Processor.
The EP-133 K.O. II has 128 MB of sample memory and 999 sample slots. That's the current model; the original K.O. II shipped with 64 MB, so if you've got one of those, halve the numbers below. Either way it sounds like a lot, until you've loaded a few stereo loops and full-length one-shots and the "memory full" wall arrives sooner than you'd think.
Good news: you rarely need to delete anything. Most samples are bigger than they need to be, and trimming them down (sample rate, bit depth, channels, length) can fit a lot more onto the device, usually without a noticeable change in sound on percussive material. EP-PatchStudio's Batch Processor does this across a whole folder in one pass.
Why your EP-133 runs out of memory (and slots)
A sample's size comes down to four things: how long it is, its sample rate, its bit depth, and whether it's mono or stereo. The EP-133 records at a native 46,875 Hz, 16-bit, and a stereo file at that rate takes roughly twice the memory of a mono one. Stack up a few long stereo samples and 128 MB disappears fast.
Two limits can stop you, and it's worth knowing which you've hit. Memory (128 MB) is usually the one you meet first if you work with long or stereo samples. Slots (999) catch you out the other way: load lots of tiny one-shots and you can run out of slots with memory to spare. Optimising file size won't help there; you'd need to remove or consolidate samples instead.
Each of the four size factors is something you can dial back, and on percussive material you can usually do it without hearing much difference.
The four ways to fit more
Run your samples through the Batch Processor before you upload, and apply whichever of these make sense.
Convert to mono. Most drum hits, basses and one-shots don't need stereo, and going mono roughly halves the size, for little audible cost on those sounds.
Lower the sample rate. Roughly halving the rate roughly halves the size. (Exact half of the EP-133's native 46,875 Hz is about 23 kHz; 22,050 Hz is the common standard near there and a fine target.) Kicks, snares, basses and lo-fi material take this well. The brightest, airiest sounds, cymbals and detailed textures, suffer most.
Reduce the bit depth. Lower bit depth shrinks the file. It raises the noise floor and adds a little grit, which on lo-fi and drum material can be a feature rather than a problem.
Trim the length. Cut silence at the start and tails you don't use. A one-shot only needs to be as long as you actually play it.
Apply mono and a lower sample rate together and a sample can end up around a quarter of its original size, four times as many on the device.
A quick worked example
A 4-second stereo sample at 46,875 Hz / 16-bit is about 0.75 MB. Convert it to mono and that roughly halves to about 0.38 MB. Drop it to around 22 kHz as well and you're near 0.19 MB, so where you'd have fit one, you now fit about four.
Do it in one pass
You don't have to edit samples one at a time.
- Work from copies, so your full-quality originals stay safe on your computer.
- Open the Batch Processor and load the folder you want to slim down.
- Set your targets, channels (mono), sample rate, bit depth, and trim where needed.
- Audition the results, then upload them with the File Manager.
Sensible settings by sound
You don't have to treat everything the same. Drums and one-shots take mono, around 22 kHz, trimmed tight, which is where the big savings are with the least cost. Bass is usually fine in mono; keep the rate a little higher if you want the top end. For melodic loops and atmospheres, keep stereo and the full rate where the stereo image or high-frequency detail is the point.
Keep the full-quality version on your computer either way, so you can re-optimise later if you change your mind.
A note for EP-1320 owners
The same techniques work on the EP-1320 Medieval, but you've got a lot less room. It has 128 MB total like the EP-133, but 96 MB of that is non-removable factory ROM (the medieval sounds), which leaves just 32 MB for your own samples. So every megabyte counts that bit more. Lean harder on mono and a lower sample rate, and be choosier about what earns a slot.
Get started
EP-PatchStudio is free to download, and the Batch Processor is included.
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EP-PatchStudio is an independent app from SquareWave Studio. It is not affiliated with or endorsed by Teenage Engineering AB.