Hi ! Here is what I've built with the bela board :

It's supposed to be an electronic sousaphone ! It's still work in progress !
I plan to publish explanation about how it works but I'm not sure what would be interesting so tell me if there's a topic in particular you're interested in !
I assume that it should mainly be the mecanic behind the pistons, the pitch detect algorythm for the mouthpiece...

About the sound design it's a custom libpd wrapper which allow me to change the pure data patch currently used ! And I have an issue with that : I'm struggling to get new interesting sounds !!! I'm pretty limited in CPU since the pitch detect algorythm is heavy... As an example, just 3-4 [expr~] with one containing a pow() function is enough to get cracks in the audio.
I've tried (and put into presets) additive and substractive synthesis, I have a sampler and a light physical model... But I'm pretty short on ideas about what sound synthesis I could use to get new sounds. If you have some tricks when trying to sound better with pd, I'm strongly interested !

Hope you enjoy that weird instrument !

    Thanks ! I remember that I tried an early version of your pitch detect algorythm ! We had done something similar with massive filtering (discussed in another topic) but mine was really less reliable ! But I have an issue with this kind of pitch detect : without the natural resonnance of the brass, it's really hard to blow the right note so I try to correct that via my pitch detect. I've tried (similarly to what you've done by rounding the midi note) to select the nearest "good" frequency to the mesured frequency... but the feeling is quite awkward when playing...
    But I will retry giving it a go, your teaser on soundcloud seems so promising !!!

      Fullitarko

      hmm, i see.

      yes you will have to sing in tune, no correction. i tried it once with correction also, but the result was very jumpy. maybe i will give that another go.

        Oh ! I'm not singing in it ! It's a sousaphone mouthpiece so I play it with my lips like any other brass instrument ! It's harder to get the good pitch but you can much more fancy rythm with brass-style lips play !

          Fullitarko nice! are you picking up the vibrations with a piezo element? might have to try that as well 🙂

            Yes ! Piezo + Differential Pression sensor which oscillates as well !

            10 days later

            The Sousasynth is excellent – great work!

            We'd love you to do a post for blog.bela.io on this if you would be interested?

            Looking forward to seeing further developments!

              4 months later

              bela_robert
              Sorry ! I disconnected from this project for a few months ! But I'm back on it !
              I would be glad to write a post on your blog if you want to !
              A few people also asked if they could buy one so I'm starting the design of a new version 2.0 to do a small serie !!! Is there any procedure to follow if I want to sell a product with bela into it ?
              I also have some practical questions like :
              -The functionalities I use on the Bela are those of the Bela mini so I'm thinking about switching to the smaller version but is the processor of pocket BB able to show the same performance ? Cause I'm not that far from a cracking sound in CPU usage...
              -Is there a way to buy an amount of bela board + pocket BB mounted without the kit ? Or at a reduced price ? I don't know how it is done, it's my first trying to sell products ahah !

              Anyway thanks a lot for your feedback !!!
              (And sorry for the late reply)

                9 days later

                Hi @Fullitarko

                No problem! That's great you would like to write a post on this. Please send me an email to robert@bela.io and we can discuss in more details there. Looking forward to sharing this with the wider Bela community.

                Regarding selling a product with a Bela inside it, sure, you can do this without any problems. There's some more info on our website: https://bela.io/about#making-products-with-bela

                In terms of using Bela Mini for the Sousaphone, the CPU performance is exactly the same as the bigger Bela so will work no problem.

                We do offer quantity discounts if people are buying a larger amount from us at once. Typically these start when people are buying 10 or more boards but if you let us know what you have in mind we'd be happy to discuss over email. We could consider selling Minis without SD and cables for example.

                Cheers!