[sdiy] Sample playback?

[Olivier Gillet]

Microcontroller + DAC + "SD-card from the dollar store" for probably
less than $10. You could reuse the code of this:
http://www.ladyada.net/make/waveshield/

Only caveat is the transfer speed of the SD card which would prevent
you from reaching very fast upsampling rates. But then, given your
constraints, you could as well store on the card and replay 5
different files, one for each replay speeds.