Dragonball

Check out Maverick Audio D1 n D2 DACs

Value for money - allows OP AMP and tube upgrades

Plenty of reviews on the Internet. Costs < $350

Go to the shop on Sim Lim Square - sigma av service unit #03-16

They do a pretty decent job n reasonable. The guy at SLT sucks

I am currently using both Windows's n MAC for my entire audio n video collection

Best performance is to play through a USB based tube DAC

Currently using a Maverick Audio D1 n D2 tube output DAC. The former comes with a headphone tube amp output

Value for money - research yourself. Can contact me if you want more info