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Building A Drumkit with Random Drum Selection

Is it possible to build a drumkit say kick/snare/hats/clap and then once you have finished playing it use a s/h and random source to then random select the samples in the kit from the pool.

Yes. Simply insert a variable speed player into your chain, load in your individually saved hits as a multi-sample, and then insert your S/H + noise into the slice control’s sub-chain. Use the same gate you have triggering the varispeed player to trigger your S/H and you will get a random hit each tick. Shout out if you need more detail!

I do this often, here’s a little moocow from a while back:

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A post shared by Bram (@constant_puckering) on May 31, 2019 at 9:47am PDT


Hello, I’ve been trying this out with the Varispeed for a long time. unfortunately I still haven’t fully understood it. Can you explain it to me step by step how you do it?
many thanks

  • choose an output channel, say 1&2 linked as a stereo sink
  • insert a variable speed player on that channel
  • click the button beneath the head of that unit (focus click) which says “Vari-Speed Player #1
  • click that head again in order to see the options of that unit
  • click select from card and you’re entering the ‘file manager’ where you can and should select multiple samples to load into your sample player.
  • click on “enable multi” on the lower display. click boxes to the left of the sample files will appear
  • you also get a similar check box above the knob M4. with that you can toggle the checkboxes of the individual sample files on and off. with on meaning selected for the import.
  • having enabled “enable multi” before means that every sample that you mark will be chained one after another, so that it will “appear” as a single sample inside the player with slice marks set between the files you chose before.
    ----------------------little break for-----------------------------
  • NOTE: as of this writing it is still not possible to choose sample files for a multi sample across several folders (edit:)in the ui of the er-301. (However, you can edit the corresponding .multi file on your sd card manually! I think you’ll have to move the sd card to an external computer for that. But maybe it’ll be possible to manipulate these kind of files with the er-301 in future?)
  • This means that each sample you intend to chain up into a multisample has to reside in one single folder. you either prepare such a dedicated folder before hand. or you dare to pack each and every sample you might ever use with the er-301 in one big and arguably messy folder :slight_smile:
    -------------------break&informercial is over, we’ll get back to work--------------
  • after having chosen multiple files by marking them in multi mode, you click the enter&commit button.
  • this will leave the file manager and present you with either a multi sample already containing slice markers or you see the list of parameters of the unit again (V/Oct, speed, gate etc…). which one you see depends on where you have left the unit when you went out for sample hunting…
  • place the cursor over the gate parameter and click the button bellow it. the subchain of the gate parameter will appear on the lower display.
  • click below “empty” and choose a gate source (external, local or global) that will trigger the slices in the multisample.
  • click on the up button to get back to the parameter list.
  • place the cursor over the slice parameter and click enter. This will open up the sample view.
  • the subchain of this parameter is probably “empty” as it says in the lower display,
  • click on that subchain with S1 under “empty”
  • either place the cursor above the subchain input and choose an external, local or global mod source by clicking M2
  • or move the cursor in the subchain above the empty chain and insert a new unit as a mod source directly.
  • the output of that subchain will monitor the mod signal though it definitely won’t affect the slice parameter yet!
  • in order to get things going go one level up from the subchain, click on gain and set it to 1.
  • depending on your weapon of mod choice you’ll have to tweak bias and gain to taste
    (e.g. bipolar mod signals might need an adjustment on the bias parameter)


  • the usual suspect for the mod source is some kind of a random generator. but it’s worth
    experimenting with periodic (sine, saw, etc.) or envelope style signals, too.
  • here i’m following @stolmine’s advice to assemble a multisample from several one shot/hit samples,
    which conveniently creates a multisample that already has slice markers added at the beginning of each one shot sample.
  • alternatively you can take complete loops or any sound file for that matter. but in order to get the random piece triggering part you’ll have to add slices manually, which will be then saved alongside the sample; so you won’t have to slice samples up every time.
  • especially when I’m collecting whole loops into a multi sample, or using single loops, I tend to reach for the clocked sample player instead of the vari-speed. The clocked one is easier for synced bars that contain several hits per slice. (Compared to slices that contain only one shot where sync to some clock isn’t that important)
  • you’ll find several tutorials on the OD wiki, that will help you deepen your knowledge. check those out.

Thanks for stepping in @mopoco! I probably should have gone into greater detail myself.

Not possible using the UI but possible if you are willing to edit the *.multi file. :wink:

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I don’t think so. You administered the first aid and I merely acted as some sort of an ambulance, because I had some spare time…
(Apology accepted though :laughing: )

Sorry, I forgot about that detail. (Might have repressed it even, because I still can’t attach my keyboard to the sound computer…) now, I’m wondering. And I will check that later… does the .multi file include/imply the slice marker info?

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Many Thanks

something am I doing wrong it only plays the first sample?

Make sure you add some gain in the slice parameter. Otherwise the triggered slice will remain the same

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Did you figure it out?

Hello I’m on vacation until today, I’ll be back home tomorrow, I’ll try and tell you if I understand. Greeting

Does everyone insert a microdelay before their trigger source when building a randomized slice player like this? In my experience, without a microdelay, I get very inconsistent behavior when triggering a new slice. Some of the time, when the slice index has changed, it will still play back the previous one until a second trigger arrives.

This seems like a bug to me because the UI of the players implies that it is constantly sampling the slice index, yet I’ll often hear the slice unchanged until a second trigger arrives unless I use a microdelay, which is undesirable because it just adds another 10ms onto the already existing latency.

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this happens with a lot of other gear as well, so i don’t consider it a bug. the trigger can arrive before the cv that changes the sample. it’s the same on the ornament & crime (and you have a built in trigger delay there as well) and various other tools. keep in mind microdelay is very cpu friendly.

yea but this is not what i’m describing. i can have a knob controlling the slice CV, change it and see the slice slider in the UI change in real time, but wait 5 seconds before triggering a sample, and the behavior I described persists… most of the time, it requires a second trigger before it correctly plays the slice that the CV points to.

I get decently consistent slice selection with a 1ms micro delay and rapid slice modulation. You might want to post a detailed report/video in the v0.5 feedback thread. Might be worth trying a different slice address mode (found in the vari-speed unit menu) just as a lark?

i think it is exactly what you described and maybe i didn’t express it properly. anyway, you know you can set the microdelay to much lower value than 10ms, right? just use fine or super fine adjustment, you can just dial in 1ms of delay, which i’m pretty sure you won’t ever notice

The UI is showing the bias (or actual value if so configured) of the CV that will be used to select a slice on the next trigger.

This exactly what @hyena is describing. :wink:

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I wish everyone a happy new year
unfortunately I still haven’t got it
the slices are set now but somehow it still doesn’t fit. a video on this topic would be really cool

I went ahead and made this for you and anyone else who might be having trouble. Enjoy my very nervous debut video tutorial! If anyone catches a mistake etc please let me know, I’m pretty sure I got the gain/bias explanation wrong but this should get you a working result on v0.5.03.