Bump Scanner Unit (formerly Bump Map)

Ooh. That just gave me an idea…


Nice! I love them as well. I made one for VCV Rack. It’s just called “Scanner”. You can check it out here: GitHub - mhetrick/hetrickcv: VCV Rack Modules by Michael Hetrick

I can’t wait for the 301 SDK to open up!

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i hope it has to do with watching a cronenberg flick

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Haha. Unfortunately I am sensitive to gore. So I’ve always been really apprehensive about digging into his filmography…:exploding_head:

if you start on the modern end of his timeline you’ll be alright. History of Violence, and Eastern Promises.

(video synth nerd showing true colors)

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my Mom was an extra in “The Fly” - shot in Toronto. :slight_smile:


Was she a wing or a leg?

Sorry, couldn’t resist. Jeff Goldblum is actually quite a good musician. See, slightly on-topic.

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Crumbs, I am only just catching up on all the new stuff… haven’t loaded it up yet, still too tired and sore from the weeks coppice restoration activities, just slowly reading through everything, and feeling my tired eyes widening at each new revelation!

This all sounds amazing!

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What are some example use cases for this unit?

@trickyflemming posted some great examples in the V0.3.x announcement thread for uses for this unit!

cool, missed that. I’ll check it out!

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One I just discovered is pulse width modulation, also with some control over the shape of the pulse (pulse to sine).

Aliasing saw–>Bump Scanner

Center at 0. Height controls amplitude, width controls pulse width, fade controls wave shape. :slight_smile:

It does sort of have a side effect of a DC offset that follows the width control. May or may not be a problem depending on your application. Quick and dirty demo.

This idea seemed to start with the concept of a Switch Matrix…can we get back to a Cliff Notes explanation of that concept?? Or generally how Neil is using it to create a Step Sequencer (I believe that’s how he’s doing it🤔)

Here is a short primer on how to do that.


(Your) Frames does some RxMx styled vca stuffs. Is that one way of understanding bump maps?

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Yeah, I suppose so. Frames can be a voltage controlled sequential switch, if you set the VCA gains to either full on or off for each frame and set the mode not to crossfade between frames. I guess it’s really a pretty similar concept to what’s happening here.

My guess is that the bump scanner can probably do some more cool things that we have yet to discover given that all of its parameters are also voltage controllable. :slight_smile:


thanks very much for this video @Joe, ideas are starting to form now!!


Nice video! I built a 4 channel switch yesterday. I found that to get the timing just right, I still had to use a quantizer on the input signal. I’m wondering if there is a way to advance each step with a trigger or gate.

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The video is really clear and easy to follow - thanks for taking the time to produce and upload it.

I’m not sure I understand what is meant by a “switch matrix”. As there is a variable height parameter for each point on the voltage axis, is it possible to produce a 2 dimensional matrix with outputs depending on an “x,y” position derived from two input values?

I should probably wait until my 301 arrives before I try to grok this kind of thing…

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I take it you were trying to build something like a step sequencer? I haven’t tried that with the bump scanner unit yet, but have been wanting to. Might get a chance this weekend. Would love to compare notes.

Hmm, I don’t know. That’s a really interesting idea though. I have found the ER-301 to be really flexible in terms of what you can build with it (and it just keeps getting more so!) For me, sometimes it requires sitting and thinking for a good long while on how to approach it. :slight_smile: Would have to noodle on that one for a bit.