Hardware FAQ

Will you offer an enclosure?

Axoloti is designed for fitting in your own enclosure. All connectors are on one side, which makes it much easier to make your own. I’ll provide a template for e.g. lasercutting your own rear panel. I believe it can fit rack-mount, floor-pedal, tabletop, and your selection of buttons, pots, faders, LEDs or other elements I cannot decide for you. I invite you to be creative on the enclosure. I’m developing this toolbox to make your personal signature sound, you add the personal signature casing to match it, fair?

Maybe check if there’s a FabLab in your neighbourhood.

Another option is frontpaneldesigner.com but I haven’t designed this.

Why big audio jacks?

Most audio engineers hate 3.5mm mini-jacks for their bad reliability. You can plug an adaptor for 3.5mm jack easily. Using a 6.35mm adaptor and cable on a 3.5mm connector puts a lot of stress on the connector and it will almost certainly break.

Why stereo jacks and not separate mono jacks?

The reason is board space and size. You can use “insert cables”, those split a stereo jack into two mono jacks. Pro audio shops sell them. As an alternative, with a little soldering and cutting a trace on the PCB you can convert the jacks into mono and add external jack connectors.

10 bit audio sounds better, so why 24 bit?

It’s easy to create lofi sounds with a hifi device, the opposite is impossible.

It’s digital processing so it must have latency, right? How much?

Axoloti is now standardized at 16 samples buffer size. Total audio input to audio output latency is a more than that, these elements contribute:

  • analog to digital conversion (filter)
  • input buffer
  • the algorithm itself
  • output buffer
  • digital to analog conversion (filter)

Check the real-world measurements here.

Why not simply use a Raspberry Pi?

A Raspberry has a higher clock speed and much more memory. It is rather a small PC, and that brings in all the maintenance associated with a PC. Running Raspbian uses so much resources of the Raspberry Pi, that little is left for realtime audio duties. The onboard audio output is very low quality and there’s no audio input. If you try this road, you’ll end up with a composition of a r-pi, usb hub, USB sound card, and running USB cables internally.

Axoloti is made to be patched with a PC, where you can focus on the audio algorithms., and then be played without PC, where you can focus on playing your sound.

Why not use a real DSP processor?

It is much harder to write efficient code for a DSP, and support in open source compilers is less common.

Can I connect my USB “midi” controller without old-style 5-pin midi port?

Yes, Axoloti Core has a USB host port, and supports class-compliant USB-midi controllers. Check here for a list of tested USB midi controllers.

Can I connect Axoloti to my (hard disk, printer, scanner, flash stick,..) USB device?

External hard disks or other usb storage media, scanners, printers, tablets… are not supported.

Why is there no battery built in?

Not everyone needs it, and it is easy to use one of those mobile USB charger batteries.

Does it have 48V phantom power for condenser microphones?

No, it would add too much to the cost. Your condenser mike probably wasn’t cheap either.

Does it fit in a modular synth Euro-rack?

Physically : not vertically, but horizontally, so it will make quite a large module, but you can use this space for knobs, lights and dials!

Electrically : Control voltages in modulars go up to +/-10V. Axoloti only takes 0-3.3V analog voltages on their control voltage inputs. So to make it electrically compatible, you need to buffer and shift the CV signals with additional circuitry.

Does it run Arduino?

No, I’m creating an environment that makes digital audio easily accessible. Arduino is very limited for doing audio processing. Some cool stuff can be done, but most of the sound production in those designs happen on the boundary between code and analog. Or with a discrete analog filter. But that imposes hard limits on the sound generation.

But can I connect it with Arduino?

Sure. It’s easy to generate MIDI with arduino, and using MIDI optocoupled input will eliminate the risk of interfering with the audio quality.

Why no digital audio inputs and outputs (SPDIF, ADAT, MADI)?

I believe there is only little demand for this feature, tell me what your application scenario is?

Can it drive stepper motors / servo’s / solenoids / relais / show lights?

There are digital outputs available for this, but they can not switch such power directly. It is impossible to design a one-fits-all solution. So you’ll need to add some sort of power circuit in between.

Can I create and distribute copy-protected extensions for Axoloti?

No effort is spent on digital restrictions management or copy-protection.