Raspberry Pi based Synthesizer

[BigPete]

I'm thinking about using the Pi to create a small portable open source synthesizer.  Similar to something like this:  http://createdigitalmusic.com/.....e-creator/

Anybody know what kind of challenges I would face, and if the pi could be suitable for this?

[colincoach]

Wow, I would be interested in using my Pi as a synth as well. No great expectations of something for £25 replicating a Polymoog or Juno but as an opportunity to get in to the 'bowels' of synthesiser infrastructure and programming would be a great opportunity and would surely make a good educational project.

[TonyD]

It would be great if we could get a software synth going on the RPi.

I was thinking about using the RPi as a MIDI controller, running some sequencing software. So far, I've put together a simple MIDI interface using the UART from the Expansion Header, just waiting for my Pi to arrive to test the idea.

[rwaltman]

colincoach said:


No great expectations of something for £25 replicating a Polymoog ...


Why not? I think a modern ARM processor such as the one in the Pi is capable of emulating an eight-sounds synthesizer released 37 years ago.

Look at pianoteq.com to see what is possible with contemporary hardware. (x86 based, not ARM, but still a valid reference point)

[Themroc]

rwaltman said:


colincoach said:


No great expectations of something for £25 replicating a Polymoog …


Why not? I think a modern ARM processor such as the one in the Pi is capable of emulating an eight-sounds synthesizer released 37 years ago.


The Polymoog has 71 oscillators, 71 VCFs and 71 VCAs. Thats still a bit of a challange for one little ARM (without floating point, IIRC).

Edit: http://www.vintagesynth.com/mo.....lymoog.php

[Artales]

Hi All, I'd like to draw your attention to this.

http://www.smproaudio.com/inde.....s/vmachine

It will amongst other things store the chaining of VSTs.

Anyone think something similar is possible?

[Themroc]

Artales said:


Hi All, I'd like to draw your attention to this.

http://www.smproaudio.com/inde.....s/vmachine

It will amongst other things store the chaining of VSTs.

Anyone think something similar is possible?


Depends on what you mean by "similar". Using r-pi as a VST host would be no fun at all - it would have to emulate some intel x86 CPU. But LADSPA plugins (and converted opensource VST ones) should work fine - like almost all the other linux audio software.

[Artales]

Yes, I was thinking of Linux.

Hmm, after looking around a little I see that the world of Linux VST is not a happy one. Wine seems to be the popular option, not an option here I'm guessing.

[darkcity]

I too would be interested in this project.

I'm curious as to what sort of music keyboard you would use.  Are there any descent MIDI ones or buid your own?

Here is an Arduino board being used as MIDI xylophone



Presumably with RPi you could do away with the computer and use it to generatel the sounds.

[tawalker]

Wonder if anyone has ported Bristol to ARM, and/or whether it's possible?

[davidgoodenough]

Yes, bristol is in the armel Debian sid repository.  Don't know about Fedora.

[Artales]

darkcity said:


I too would be interested in this project.

I'm curious as to what sort of music keyboard you would use.  Are there any descent MIDI ones or buid your own?



I've got one of these: http://www.akaipro.com/lpk25

Is that the kind of thing you mean? Supposed to work with Linux without drivers.

[Cylon]

No this would be interesting. I would be all over this if we could build a mini PI - FAIRLIGHT.

Now that would be amazing. Would go so well in my studio

[colincoach]

Artales said:


darkcity said:


I too would be interested in this project.

I'm curious as to what sort of music keyboard you would use.  Are there any descent MIDI ones or buid your own?


I've got one of these: http://www.akaipro.com/lpk25

Is that the kind of thing you mean? Supposed to work with Linux without drivers.


Hmmm....between £35 and £45 in UK.....worth looking at if Linux compatible then?

[colincoach]

Cylon said:


No this would be interesting. I would be all over this if we could build a mini PI - FAIRLIGHT.

Now that would be amazing. Would go so well in my studio


Yep that would be amazing.

I seem to remember at the Science Fiction Convention in Brighton in 1982 we were demoed one - why a science fiction convention I don't know - but the large crowd were blown away by it!!!!!

[Zodiak]

Its a case of using it at what its good at, yes it should do a good fairlight clone, but thats pretty awful now, a mellotron, organ or even electric piano, but it isn't going to be able to do a convincing grand piano or full orchestra, it just doesn't have the speed or RAM.

However don't let this stop you, my main workhorse for years was a Roland JX3P, which had 6 voices. In practice I only ever used it for one hand at a time so that limit was never a problem.

On the same track I reckon it would be an pretty damn good frum machine, or bass synth.

Were you thinking of using it with a USB keyboard or a MIDI interface?

[BigPete]

Were you thinking of using it with a USB keyboard or a MIDI interface?



I was thinking of using a USB keyboard at first.  Maybe trying to hack together a midi interface later.

[RMW5]

I can't think why you would want to use an R-Pi (no FP) to generate tones when there are plenty of DSP-laden synth modules with everything from 128-voice pianos to every grunt and fart you could ever need plus lots of FX and samples that have already been created, but a new MIDI-control surface would be nice because the Linux versions (http://linux-sound.org/midi.html) are not always as polished as their PC and Mac equivalents.

Also Linux support for USB/MIDI interfaces is quite solid so creating MIDI interfaces through the expansion headers is probably not worth the effort.

[BigPete]

I can't think why you would want to use an R-Pi (no FP) to generate tones


Because I thought it might be a fun opportunity to learn some things!

[Themroc]

RMW5 said:


I can't think why you would want to use an R-Pi (no FP)


The ARM1176JZF-S does have FP. And even if it had only int it could do sound synthesis.


to generate tones when there are plenty of DSP-laden synth modules with everything from 128-voice pianos to every grunt and fart you could ever need plus lots of FX and samples


Where can i get one of those for us$40?


Also Linux support for USB/MIDI interfaces is quite solid so creating MIDI interfaces through the expansion headers is probably not worth the effort.


The effort is a laugh: about 1 optocoupler and 2 resistors.

[RMW5]

Where can i get one of those for us$40?


Flea-bay, like all the other bargains.  Maybe not $40, but not much more and you get much more bang for your buck


The effort is a laugh: about 1 optocoupler and 2 resistors.


Maybe, but at £3.45 from http://www.cohaku.com/item/usb.....-vista-mac, it isn't worth the bother or the coding (and you forgot about the wiring and the connectors.

[mole125]

RMW5 said:



Where can i get one of those for us$40?


Flea-bay, like all the other bargains.  Maybe not $40, but not much more and you get much more bang for your buck


The effort is a laugh: about 1 optocoupler and 2 resistors.


Maybe, but at £3.45 from http://www.cohaku.com/item/usb.....-vista-mac, it isn't worth the bother or the coding (and you forgot about the wiring and the connectors.


And why would a mountaineer want to climb that mountain – someone else has already gone up it…

The RPi is all about the pursuit of new knowledge and experiences, this can be worth far more than something being easy.

Also I imagine there would be ways to get the GPU to perform some very powerful operations giving you extreme amounts of bang for your buck - if your maths and coding skills are up to it.

[RMW5]

And why would a mountaineer want to climb that mountain – someone else has already gone up it…


Well don't let me stop you (I am sure you won't). There are lots of potential projects along the same vein:


USB connected paper tape punch / reader (or 80 character punched cards)
coating a drum with iron oxide and reading and writing data on the rotating drum with fixed magnetic heads
build your own 5v power supply

but you can probably get a better alternative from a shop for not very much money, and speaking of not much money I just looked on eBay where there were some pretty decent rackmount synth modules for around £20 (Emu, Korg, Roland, Edirol etc).

[Themroc]

RMW5 said:

on eBay where there were some pretty decent rackmount synth modules for around £20 (Emu, Korg, Roland, Edirol etc).
Yeah, if by "decent rackmount synth" you mean some boring old sample player like a U-110 then u're right. But what i'd call "decent" is more like

matrix-1000: EUR 231,00 and still 20 hours to go

JV-1080: EUR 76,00 also 20 hours to go

even a not-so-hot K1M is already at EUR 50,00 (20 hours).

À propos old sample player:

The Fairlight CMI IIx library. Add this and some additive synthesis, perhaps from here et voilá: r-pi becomes a $100 000 music workstation

[RMW5]

Yeah, if by "decent rackmount synth" you mean some boring old sample player like a U-110 then u're right. But what i'd call "decent" is more like


Well, if you think you can get a 64-voice polyphonic, 16-Part multitimbral synthesizer with 512 instrument sounds, 8 drum kits, 40 built-in effects and better sounds than Roland engineers out of a Raspberry Pi, then I will be the last person to stand in your way.