MD Voices diagram

Do you know if there is a diagram of the MD’s voices structure? I mean, the synthesis chain that underlies the voices (oscillators, filters, fx, envelopes etc …)



i know this diagram but i’m curious about the synthesis chain, which kind of waveform, filter, amp etc…

each machine is made differently, playing them is the best way to work it out.
have you got an md or trying to make something similar?

all tracks have the same multimode filter, envelopes can be done in some machines or via LFOs/plocks.

i have a MD :slight_smile:
but I would like to study the dsp. I’m a manufacturer of an eurorack module which has 3 synth DSP alghorithm + 1 for the samples and 4 voices


Depending on your knowledge of each kind of synthesis used in the Machinedrum you should be able to get a rough grasp on the construction of each machine by looking at the Machine Reference (Appendix A) in the manual

If you are interested in the PI machine (physical modelling with waveguides) there is a paper by its creator (and Elektron co-founder…) available here:

I could have sworn I had a paper by the author of the EFM machines as well, but I can’t find it anymore… Should be in the Chalmers vaults somewhere.


Well, here we go…

TR-X paper:

EFM paper:

But sadly looks like you’ll have to check them out from the library somehow.


unfortunately it requires login details which I don’t have, but thanks for finding it.

Sorry about that. Updated with the correct permalinks.

The TR-X paper is called “Digital drum synthesis TRX for the Elektron Machindrum SPS-1” and is written by David Möllerstedt

The EFM paper is called “Syntes av trum- och percussionljud med hjälp av frekvensmodulering”, which translates to “Synthesis of drum- and percussion sounds by means of frequency modulation” and is written by Erik Larsson

Fun fact, David Möllerstedt went on to found Teenage Engineering and Erik Larsson, I believe, now makes the Lekholm DM48X MIDI harmonica.


Looks like these are references to printed copies of graduation theses?

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Yes, these are papers written by the various developers behind the Machinedrum. They’re not available online besides these database listings, but it looks like you can check them out at the physical Chalmers library in Gothenburg. I’m due a visit this summer so maybe I’ll take a peek. :smiley:


take one of these with you please



Due to unforeseen circumstances I found myself in Gothenburg this afternoon.

Will compile the PDFs very soon. The TRX one needs some translation.

They are both much more in depth than I though, super exciting.


Tack gud för ”tvångssvenska” här i Finland! :grinning: (Alltid tyckte om svenska faktiskt.)

Really looking forward to having a look at the PDFs! Thanks @Ess!


This is the news! Can’t wait for the PDF! Thank you for your trip to Gothenburg!

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Here we go. :slight_smile:

efm.pdf (2.3 MB) trx.pdf (3.3 MB)

So actually what happened was that I was in Stockholm over the weekend but my flight on Sunday got cancelled – the best option I could find was to take the train to Gothenburg and fly back home from there. So naturally this was a great opportunity to scan these papers.

Unfortunately the TRX scan is a little wonky at parts, should have used a flat bed scanner in hindsight but I was in a hurry and the overhead ones they had in the library were really quick to use.

Both are in Swedish, I would like to translate these as I think they are historically important as well as a good resource.

But even if you don’t know Swedish there are a lot of cool parts - surprisingly the TRX paper covers a lot of the Motorola 56303 assembly implementation! The FM paper has a lot of nice tricks and signal flow diagrams as well.

I converted the scans so that the text is machine-readable so hopefully one can get by with some auto translation for the time being.


@Ess You are a treasure - thank you for making the extra effort to preserve this history!


Hear hear

Many, many thanks for scanning and posting these. I would like to translate these as well so if I can help you in any way (native English speaker) let me know.


My pleasure!

I’ve been obsessed with the Machinedrum for so long that it was a treat for me as well. I think it’s such a unique machine and endeavor that transcends the company itself in some ways, it has a cultural and technical impact that is quite rare.

Also just thinking plainly about the time and circumstances of it as a project and product; it came from a fresh, tiny company that were comprised of (mostly) a number of college students with a vision that is still unrivaled today. If you would come to any music tech company nowadays with the same specifications they would turn it down immediately for being too risky and ambitious.

I think about that a lot, it’s almost a miracle that this machine was manifested at that point in time and place. So many visionary and talented people came together to make this happen, and they executed that idea beautifully.

(EDIT: in fact, I read the initial spec/concept of the Machinedrum and every bit of it was as ambitious and visionary as you would imagine. It didn’t just happen, someone set out to make the most advanced drum machine ever, basically. I love how bold that is)