I have experimented with the keybed from the PSS A50, it conforms to the schematics. I have achieved to use it using 11 gpios and a 4067.
great little enclosure with keybed for 80€.
Sadly the original 4 battery compartiment is not enough voltage for the axo. I added a 6 battery compartiment that provides almost 10h autonomy.
Here’s my build, second prototype, going to redesign it a bit neater but for now it works fine, the idea is to use it for trying stuff out, so then I can build further designs.
Build using aluminium composite board, the kind used for sign making, fairly easy to work with, the brand name is Dibond but any ACM type stuff would do, I used threaded M3 pillars to hold it together.
I have one of my prototype enclosures for sale. More info here.
Outer measurements: 12,6 x 7,5 x 3,5 cm
Fits one Axoloti Core with the DIN MIDI PCB removed (see above link).
Top and bottom are wood, so you can drill holes for pots, switches, etc. Sides are black glossy acrylic. Holes are 3mm diameter.
Price is 30€ shipped inside Germany or the EU. Payment via PayPal Friends & Family. Pickup and cash payment possible in Cologne, Germany as well.
Hello everybody. Today I'm proud to present the Poli-Ax.
This creation is the culmination of the wisdom imparted on me by the many good people of this forum, and all over the internet, to help someone who went into this project without knowing what GPIO means, or what 3.3v logic is, or how MIDI is programmed (let alone understand C++ whatsoever). It was a project that was made on impulse and driven by a vision. So while it was built with my hands, I consider it a product of the world.
The name is a portmanteau of "Polivoks", the Soviet-era synthesizer, and Axoloti. The likeness to the Polivoks is only spiritual. I liked the rugged, impenetrable look of the device, and the aggressive character of its sound.
The enclosure is a gutted 4" speaker stage monitor that I got broken off of ebay for $3. The faceplate, logo, and sides are all 3d printed with a printer that I bought as a result of this project (hoping to maybe break even by offering some unrelated printing services with it 
).
12 of the 16 pots, and the Adafruit Trellis are attached to a Teensy 4.1 transmitting MIDI via UART. The bottom 4 pots, OLED, and PS2-extracted joystick are all connected directly to the Axoloti. The 4 pots are used to toggle between MIDI CC's in order to make 3 pots out of one. Once I'm more confident with programming, I may move the bottom pots to the Teensy to serve the same function but save resources.
Built into the side is a passive stereo mixer with two stereo outputs (not two mono). The Poli-Ax serves as an effects unit as well as a synth and sampler, so I'm routing all of my other devices into the mixer to the Poli-Ax, and using the other stereo out as a dry mix. The mixer isn't wired to the Axoloti at all, but I may wire one of the stereo pins to save plugging a cable from the side into the front, though I kinda like the modular-esque feel for the time being.
Setbacks that I encountered during the project:
- Crappy soldering iron
- Bought an entire pack of pots which didn't read from the middle pin. Bad batch perhaps. First time I've ever wired potentiometers so imagine my frustration in thinking it was something I was doing!
- What seemed like the most useful video for a "DIY passive mixer" on YouTube shows a completely incorrect diagram for how to put it together. Another case of me thinking it was something I'd done wrong 
Things I learned from this project
- Basic electronics and soldering skills
- Basic programming in the Arduino IDE and differences between microcontrollers
- Prototyping and product-design (not mass producing these, but the aesthetic is crucial)
- 3D modeling and 3D printing
There's a long way to go before calling this machine complete, but the biggest parts that once seemed monolothic and insurmountable are now behind me. Thanks once again. The Axoloti rules.
Yet another cardboard based synth.
This is an Harmonic synth with steppy waveforms reminiscent of the RMI harmonic synth.
That faderbank looks super interesting.. Where did you get it? . It immediately reminds me about the Buchla easel
How did you do the multiplexing?
greetings!
s
Hi servandisco
These are ordinary sliders with cardboard and Fimo... I use three 4067 for multiplexing.
I will add some objects in the community repository when they will be reliable.
My friend @steveo made me this for my birthday - Nintendo themed axoloti 
I love it! Controls/buttons nice and responsive.
Thanks for the screen objects, @SmashedTransistors
Finally found a use for Axo #3, which has been patiently waiting for about 2 years:
Now before anyone gets too excited... this IS for my modular but it ISN'T interacting with cv. I have a bitbox micro which has great midi implementation, so having Axo in the rack to act as a midi device and/or host is huge because I can easily plug in controllers/keyboard/ipad to control parameters or send sequences. I added the 4 encoders and LEDs to let me patch up extra CC control, but I also just discovered that the bitbox has enough input gain that I'm able to plug my guitar into Axo, then out to the BB to record samples on the fly so I currently have the controlling input gain and a couple parameters on my eternal favorite @TheSlowGrowth reverb.
I added leads and it's powered by 12v right off the euro busboard. Cool!
If you kept the MIDi section of the PCB, you can always make an extension module that links with one of the couple of CV to MIDI Eurorack modules out there. You could do all the wiring behind the panel too if you wanted to save HP space.
I bought a Doepfer A-192 for my Axo but use it more with my Nords nowadays. It gives you 16 CV ins over MIDI CC commands.
I am using the midi section of the board -- changed out the din jacks to 3.5mm. This lets it work with the 3.5 midi in on the bitbox. In this instance, using it for midi is way more powerful than using it for CV. I just added the preface before people started asking how I got it to send/receive modular levels. (because I didn't) haha 
I just made a new topic on my latest enclosure. Since the title of this post seems to fit my post I post a link here:
grts!
hey man, thanks for calling it beautiful hahaha.. but unfortunately, no, it has been dormant since about 2 years now. life and all, you know... it still is at the same, i'd say 90%, completion state, the axoloti part is working perfectly. i "only" need to make a final frontplate/enclosure, better internal wiring and decide whether/which analog effects i want to use after the axoloti part. since that was one of the issues, my implementation of the max11300 i am using for CV to control the analog side of the synth was a bit noisy. and then obviously a ton of finetuning/fixing, once the box is closed.
but yeah. couldn't find the energy to work on it the last - ouch - two years. maybe 2022.
will send you a dm..
Dronebox for a buddy, with HP/LP filter, a bunch of oscillator combinations that you can blend together, and LFOs that you can send to VCA, osc freq, filter freq, and the option to use the LFOs and filter to mangle amplitude/pitch/filter of an incoming signal and blend it with the drones (or not). Fun build!
