Microtonality and the Striso

Any advice on using the Striso as in instrument for exploring microtonality

Welcome @voximo!

The main way of exploring microtonality with the Striso board is by using different syntonic temperaments. For these tunings the nice thing is that the isomorphic properties of the keyboard are kept.

A selection of temperaments is directly available from the board itself. These are 12tet, 31tet, 19tet, 5tet, 7tet, 1/4 comma meantone and pythagorean.

Other syntonic temperaments can be selected by sending a 14bit value to CC1 (LSB to CC33), this set the size of the fifth to anything between 680 and 720 cent, similar to how the tuning is selected in my online tuning exploration tool. This is also how the Striso Temperament Compass works.

In the near future I plan on implementing a configuration system, which let you set a pitch for each of the 17 keys per octave. Also I’ll implement a 7-limit Just Intonation tuning and Indian Shruti tuning to be directly available.

If there are wishes for other options feel free to discuss them here,



I know you’d planned on sharing the source code at some point in the future. I imagine there are a number of ways people could experiment with different configurations in the general sense if it were available. Do you have a rough timeline for doing that?


Hi Frank,
Thanks for asking, the source needs some checks and a readme update. Shouldn’t take too long. It helps when people are asking for it though :slight_smile:.

The source for the previous version and for the bootloader are online already.


@fkberthold The source code is now updated to the latest version!

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Piers Sir!

You are godly in my eyes!

I just downloaded the source, after adding the necessary compiler I was able to modify and customize the default settings (config.h & synth_control.cpp for anyone who’s looking), compile it and drop the new build on my Striso without breaking anything.

Of course without a bit of fooling around I won’t be 100% sure it worked. I’ll have to change an LED color or something a bit more obvious to be sure. But, this is fantastic. Once again, thank you for all the hard work.


I’ve got several requests for the non-octave Bohlen-Pierce scale, and found two appropriate options to map it to the Striso. The colors of the keys don’t make much sense, so I’ve shown those with the line thickness for reference.

Option 1, following the progression of septimal major thirds (the BP version of the progression of fifths):

Option 2, where the tritave takes the place of the ocave:

Both are isomorphic, and interesting ways to explore exotic harmonies.

For now I’ve put them on the last two free slots of the tuning row (until the configuration system is in place). They’re available in firmware v2.0.5.

For less regular tunings I still have to implement the configuration system.

– Piers

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