ElectroTechnique says that their Teensy based polyphonic synthesizer can be built for under 100 dollars including the PCB, front panel and all the components.
It’s an impressive looking machine at a remarkable price although you will need to source the rest of the components yourself. ElectroTechnique can supply you with a partial kit containing the front panel, the main PCB with SMD components already soldered, the IPS 80×160 display and a 3D printed standoff to mount the display. That’s all yours for $36 plus shipping. You’ll need to buy a Teensy 4.1, an Audio Board, pots, encoder, buttons, connectors and few other bits and pieces that are detailed in the build guide. There are also plans for building a suitable enclosure although it will work fine with just the front panel.
The Teensy firmware offers 12 voice polyphony with 2 oscillators per voice, individual LFOs and pitch envelopes, lots of pulse width modulation and noise generation. The state variable filter has its own envelope and LFO. You can stack the oscillators into dynamic or chord unison and there’s plenty of cross-modulation on offer. At the end of the chain is a stereo ensemble chorus effect. It comes with a bunch of presets and you can save and recall your own.
TSynth sounds pretty convincing – check out the video below, that’s a great demo and it looks pretty decent too! Trying to work out what the catch is? Nope, it’s just good and cheap at the same time.
ElectroTechnique is looking for help with distribution as they can’t seem to make enough to keep up with demand. Currently, you can buy them direct from their Tindie store and they ship directly from South Korea. Apparently, they appear in small batches so your best bet is to join the waiting list.