Small DAC With Balanced Outs

If USB is an option and you only need the DAC to have one input, then I'd go for the HRT Pro. Fabulous sound, balanced output, powered by USB, so even less cable/plug hassle. Check out the 6moons review. Although it is worth noting that the Pro was not run through a truly balanced set-up, the Esoteric pre isn't a fully balanced pre IIRC. So even in that review, the Pro may not have been heard at its best. But it is tiny, balances and a stunner of a performer. No one will even know it is there unless you tell them...

PS Audio Digital Link III or Bel Canto Dac 3 meet your criteria.

Scott Nixon DAC's are physically small as are some Audio Note and Audio Sector models. The Nixon and Audio Sector models are also available to the DIY crowd so the "box" can be constructed anyway you like.

Jeff

The Apogee MIni-Dac should fit the bill.

Channel islands Audio VDA2 is balanced out if used with the Harmonic Tech cable. It locks on when a signal is present otherwise is off. I use it with the VAC1 power supply.