Open source hardware is not expensive, about $35 usd for a Rasberry Pi board, the major problem is software cost, so I think a new business model will come out and it has no power stage, so a TK board is still needed.

Btw, we just finished new engine sound simulation for TK, the result is over my expectation, will fine tune it and extend to 16/32 steps to see how it performances
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https://youtu.be/MV3pARCWvcM ps. sorry for the poor audio recording quality, my new camera, Canon 5D Mark III, seems need a external mic for better sound recording.