Chaining several Axoloti boards - SuperMega Ambika 6000

#1

Hi,
I have an Ambika from Mutable Instrument and I love its filters. My main problem with it, except that it's not a modular synth, is that waves are bad sounding - imo. I think that the ATmega644p is the only dsp available that we can sold as "DIY". It's not really powerful and I doesn't like the "DSP"/software part of the ambika like its wavetables. But hell yeah- those filters...

So I was thinking, is there anyway to add an Shruti/Ambika filter to an axoloti ?
In my dream, it will be polyphonic, so here is my main question :
Is it possible to chain 3 axoloti with the 6 ambika filter ? One axo board would have 2 filters (stereo) chained with 2 others axolotis with also 2 filter each. So we could have a 6 voices poly synth -modular and really nice sounding -
this running in one patch.

I saw on few post that it's possible to chain some axoloti, sending audio directly via the DAC from the board.
But is it possible to run one patch on 3 axolotis ?

Ehhhh - Thanks !

#2

The Ambika oscillators are actually on the voice cards, along with the analogue filters.

The chips responsible for the oscillators are ATmega328s (as used in many Euro projects, and the original Arduino/Genuino boards).

While the wavetables are 8-bit, each voice card has a 12-bit DAC, so the oscillators are smoother than those of the Shruthi-1.

The larger ATmega644 on the mainboard is used for control and modulation signals, MIDI I/O, voice-allocation etc., and handles the UI.

a|x

#3

So, it might be possible to control Ambika voice cards with the Axoloti, but that's not going to give you better oscillators, since the Ambika oscillators are on the board, and don't have any way to input an external signal (ie from the Axoloti) to the filter section.

a|x

#4

You might be able to control a Shruthi-1 filter board from an Axoloti, though, and run Axoloti oscillators through it, for a cool monosynth with analogue filter.

a|x

#5

Oh, i was thinking that the Ambika was using the same filters as the Shruti. So, if the project is possible I will sell my Ambika and buy 6 shrutis filters instead.

I've got enough mono synth atm, so a better question is :
Is it possible to chain 3 Axolotis together with 6 Shruti filters running in one patch ?
(I mean, is it possible by the software -and hardware : does one axoloti can be linked to another one and output its sound to the filter ?)

Thank !

#6

it depends what you mean by chaining...

you can setup 3 axolotis with the same patch, and write an object that splits incoming voices to the three boards via midi. (or maybe there is already such an object)

you cannot just chain three boards together and run one supermega patch on it :slight_smile:
there is some development going on to interconnect two axolotis digitally to pass audio and control data, but this will also involve a sending and receiving object, and two independent patches on the axolotis.

#7

Hum, It will be a pain to Edit parameters on 3 differents patch on 3 axos each time...
I don't think we need to pass audio through axos for this project, maybe just data ?
Could we do something like : 

                       |-> Axo 2 ->Filter 1&2 Output
                               |
                             Data
      MASTERPATCH----->|->MasterAxo ->Filter 3&4 Output
                             Data
                               |
                       |-> Axo 3 ->Filter 5&6 Output

Or at the running time, when loading, the first axo send the patch to the 2 others ?

                       |-> Axo 2 ->Filter 1&2 Output
                               |
                             PATCH
      MASTERPATCH----->|->MasterAxo ->Filter 3&4 Output
                             PATCH
                               |
                       |-> Axo 3 ->Filter 5&6 Output

Does axo has a port to send data besides the usb one ?

Thank,
Cice

#8

you don't have to edit parameters on 3 different patches, they can respond to the same midi cc for example...

#9

Yup, but when editing a patch - like starting from scratch. I use CC for performance, but we can't for designing patch, object etc.

#10

Have you tried the alternative firmware for the Ambika called YAM? Someone improved on the design of the oscillators and also added new ones

http://mutable-instruments.net/forum/discussion/7717/yam-alternative-ambika-firmware/p1

#11

@drox :
Yep, I've already tried it. But my question wasn't to improve my ambika board, it was how to chain several axoloti.

I've see a branch on Github from @johannes named SPI_Link, does it have something to do with chaining ?

Cice

#12

yes the spi_link contains development/experimental code for linking boards, but I suspect it will be a while before this makes it into a released firmware (early days)

... if you have experience in this kind of firmware dev then its open source, if you want to 'lend a hand' :slight_smile:

#13

Thank,
I know a little about code (I've coded some audio/Interactive app with OpenFrameworks the last two years, but I'm not deeply into DSP). I haven't found documentation about SPI_Link or anything to start with - despite the github branch comparaison.

Cice

#14

theres no documentation, as its experimental development code... so not at a stage where it can be used.
btw... the priority at the moment is getting 1.0.12 out, so nothing is happening with this branch until after that, then its likely to be merged into the main dev line... but I dont know if the audio link is a priority for that dev release yet.

#15

Indeed releasing 1.0.12 is the first priority, after that I plan to merge the spi_link branch, and get it ready for consumption.

#16

Oh okay, thank you, I'll wait a little !

Ciceron

#17

Did you have any luck controlling the Shruthi filter boards with Axoloti?

#18

Hi,

I use the Moka FilterBoard from Olivier / Modulart.


Everything is ready to use via jack.

Works great !

Ciceron