Hard-drive based media players aren't anything new, but hifi equipment actually built from old drives are somewhat rarer. At Hifiduino they're using an Arduino microprocessor to construct a DIY preamp ...

I was delighted when reader and DI contributor Jim Brannan proposed writing up his base-3 DAC design. Like Charlieplexing, his idea makes use of tristate outputs to wring more information from a pin ...