not in any order of preference:
ibasso D10/D12 (you probably have to swap the opamps from stock to get the warmness)
rudistor linearossa W3
centrance DACport (takes usb input only. transportable, but not portable)
uber muzik Tiny Tube DAC (tube amp, needs power supply. transportable)
nuforce uDAC2 (usb powered, transportable)

'somewhat' out of your budget but i feel is totally worth the price: pico amp/dac.

there should/could be more that i have missed, but these are the ones that i can recall off the top of my head, prices should also be somewhere around your budge too. have fun auditioning them!

or to make things slightly easier, do you already have got any amp/dac in mind?

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Added on October 19, 2011, 1:22 pmoh ya, terrygls,

bring your reply to this thread: http://forum.lowyat.net/topic/1938025/+640

thanks!