Little Dot MKIII with lots of tubes:
For the HD600: Mullard EF95 driver tubes and Electro Harmonix 6H30Pi Gold Pin power tubes.
For the HD650: Voskhod 6J1P-EV driver tubes and Novosibirsk 6N6P-IR power tubes.
For the HD800: El Yugoslavia 6HM5 driver tubes and Novosibirsk 6N6P-I power tubes.
iPhone/iPad with Nuforce iDO (using DAC only through RCA out)
Laptop running Foobar2000 with Nuforce uDAC-2