Work in Progress: LinnStrument Backpack

[TigerBalm]

I'd love to have an all in one LinnStrument + synthesizer instrument. So, I'm making a synthesizer that attaches to the side of a LinnStrument using the shoulder strap screw holes. It powers the LinnStrument through the USB port and also receives MIDI through the same port. I want to make something that's fun to use and discoverable like an OP-1. To me that means lots of user feedback through a display/LEDs and minimal button combinations.

The synth engine is quite simple: (macro) oscillator -> filter -> amp -> effect 1 -> effect 2. From Roger's presentations I believe the expressiveness of the LinnStrument can make even simple synthesizers sound great. There are buttons for X, Y, and Z expression so you can easily edit those settings. You can set modulation targets by holding an expression button and wiggling a knob (Connor Golden's idea).

Last weekend I got simple synthesizer code and all the hardware working on battery power (I had a lot of help from a friend I met on YouTube). There is a lot of work yet to do to make the UI and make the synthesizer sound good. If you or anyone you know is good at DSP/embedded software please reach out, I'm looking for help!

If you have any wishlist features or synthesis methods please let me know so I try to can bake it in (edit: if possible, please link to a video/sound example if you suggest something so I can know what to aim for).

Lots of progress pictures and videos below. Thanks!

Imgur Galley:
https://imgur.com/a/U9jhXEG

First Sounds:


Code Status:

[epoch2000a]

I've been wanting something like this since I got my Linnstrument. I want an all-in-one portable instrumment with Linnstrument as the controller. I've thought of building a wood box that contains a Dave Smith Tetra, some speakers, and a battery, with Linnstrument forming one side of the box.

Good luck with your project!

[BobDog]

Brilliant

[t-IB]

Yes please!!!

As for suggestions FM is always good - even just osc2 to osc1 and/or osc to filter. Some kind of wavefolding would be nice, better still complex oscillators, with integrated wavefolding and FM/AM. Basically if you can bolt on a little polyphonic buchla I'll be delighted!

Code wise I'm rubbish, but a reach out to technobear might be worth a shot - he ported a load of mutable stuff over to axoloti patches irrc and does the orac stuff - I'm not sure if he has a linnstrument still but he's into expression.

Good luck - I'll certainly be following your progress and would be very inretested in picking up what you finish.

Edit: I'll add that the cc faders on the linnstrument are excellent for programming a number of choice parameters - I have my axoloti set up in that way (with a sensel morph) so that each patch I select can be tweaked by the control surface rather than the interface, which in the case if the axo consists of 2 tiny buttons!

[minorAfno]

Wow, that looks exciting! Is it anything you're planning to sell later? Crowdfounding or something?

If you have any wishlist features or synthesis methods please let me know so I try to can bake it in.

+1 t-IB's suggestion of a little Buchla.
Also, as I read you mention "Macro oscillator", I think of Mutable Instruments, which has a good selection of sound sources, including some string /physical modelling ones.

As for filters, consider some comb filters and phasers too. It's amazing what you can achieve with a noise sound source and key tracking these filters!

Reverb and delay sound good to me as FX.

I've seen in the pictures your design includes the Linnstrument's wood panels. Some people remove this from theirs, just so you know.

[48cube]

That looks awesome! I've been also designing something similar utilizing Axoloti, DIY wooden resonator body and DML speaker drivers that would attach beneath the Linnstrument. Something like Onde.
TigerBalms thingy looks really smooth. Looking forward to further development.

[TigerBalm]

Wow thanks everyone for your nice responses! I'm getting more excited.

Yes please!!!

As for suggestions FM is always good - even just osc2 to osc1 and/or osc to filter. Some kind of wavefolding would be nice, better still complex oscillators, with integrated wavefolding and FM/AM. Basically if you can bolt on a little polyphonic buchla I'll be delighted!

Do you have a video you can link that shows this sound? It would help to know what I'm aiming for.

Also, one unique thing here is we have to take these sounds and make them jive with expressive play. How are those timbre parameters animated on a Buchla? Do you have any guesses about a good way to modulate them with the XYZ output of Linny?

Wow this technobear person seems like a genius. I heard about Orac before but watching his youtube videos now it looks like there's a huge crowd of people who love Orac and are gushing over him. Looks like a might need to get an Organelle since I need to learn Pure Data anyway for synth prototyping. I don't think I'll reach out to him just yet.

[TigerBalm]

Wow, that looks exciting! Is it anything you're planning to sell later? Crowdfounding or something?

Also, as I read you mention "Macro oscillator", I think of Mutable Instruments, which has a good selection of sound sources, including some string /physical modelling ones.

Reverb and delay sound good to me as FX.

Right now it's just a personal project, I've never made my own product to sell before. If things go well I'd be happy to sell them but there's a lot of stuff I don't know. I'm most nervous about those Lipo batteries.

Yup I lifted the term Macro Oscillator from MI Plaits. I only have space for two encoders, so each block in the block diagram needs to be abstracted down to two parameters. I definitely want to look into the Plaits code and see if I can implement any of those models on Teensy. I think the first three oscillators I will make are 1: square wave with PWM, 2: wavetable, 3: vowel oscillator from Plaits.

Agreed, Reverb and Delay are the first two effects. Hopefully I can make the effects and oscillator swappable.

[peter.antoniou]

I had similar thoughts - 3d print a case that just extends the LinnStrument to contain a synth and any off the shelf usb battery pack. I was thinking something like Zynthian might be cool - lot of flexibility, could even add a companion app for the LinnStrument to handle the things that are too hard to do without a display.

[mrspiral]

Technobear hangs out a lot on the polyexpression and lines forums. He’s a wonderful fellow and very approachable; writing him a quick letter won’t do any harm at all.

[minorAfno]

Do you have a video you can link that shows this sound? It would help to know what I'm aiming for.

Also, one unique thing here is we have to take these sounds and make them jive with expressive play. How are those timbre parameters animated on a Buchla? Do you have any guesses about a good way to modulate them with the XYZ output of Linny?

Have a look at Aalto by Madrona Labs. A good example of west coast sound with a lot of timbre variations. Also the MPE implementation in that synth is great in how you can freely assign XYZ modulation. I like specially to combine the envelope with aftertouch to control amplitude.

The FM module in Plaits makes also good sounds.

Good luck and keep us posted!

[t-IB]

Do you have a video you can link that shows this sound? It would help to know what I'm aiming for.

I'll put something together today - I'm specifically thinking of the 259e oscillator core, which is essentially two oscillators, with the secondary (modulation) oscillator affecting the first in various ways - there's AM, FM, and modulation of a cross fader on the main osc, selecting between two waveforms, and a wavefolder. CV control of all of that (so think there for MPE) and some mad code scanning on the primary osc. It's fantastic!

Somebody else will have described it better and have some sound examples so I'll add a few links later... The Aalto suggestion is a good one, since it's Buchla inspired. Theres also an official softtube vst module, though I've no idea how it sounds by comparison.

Anyhow, while I'm somewhat joking about a tiny buchla on the end of the linnstrument there's a lot to learn there and a huge amount of euro modules and synths these days tend to borrow much from Don's approach (wavefolders, gates, random, complex oscillators etc). The Eagan Matrix, and indeed axoloti MPE based patches, might be worth a look for inspiration too?

Edit: info here on the vst https://ra.co/reviews/21896
And some tweaking of the real thing here:
At one point I had a wav file of the memory (waveforms A, B & C) being swept through - I'll see if I can find it... it's very angry sounding.

If there's anything I can do to help further let me know...

[t-IB]

Thinking about oscs I believe the orgone accumulator is teensy based and open source - perhaps worth a look: https://github.com/jakplugg/Orgone-accumulator

[TigerBalm]

Printed the bracket to stick the synth to my Linny. I think this package would be a nice size when paired with a LinnStrument 128. My printer is being very temperamental right now.

[rtwfroody]

That looks really cool! I'm figuring out what all I'd need to take my Linnstrument and play it elsewhere, so really interested in this project. Although I'm hoping to use pianoteq sounds so I'd need a completely different synth platform. But it's still really cool to follow this project.