I'm thinking of making the 2A03 controllable via MIDI by using the tutorial found in these two blog post:

http://shiftmore.blogspot.se/2012/11...th-part-i.html
http://shiftmore.blogspot.se/2012/11...ynth-part.html

The schematics: http://1.bp.blogspot.com/-qGIid217Vp...no_spi_sch.png

Instead of an Arduino Uno I want to use the Teensy. The only obvious issue I see here is that the Teensy is using 3.3V rather than 5V. But according to some other posts I've read, the 2A03 will recognize 3.3V as high, so it shouldnt be a problem when sending instructions to it. And the digital pins on the Teensy are 5V tolerant, so that shouldn't be a problem either.

All the other things that need 5V supply can be connected to the Vin, right?

Are there any other issues I should be aware of?