There's one for sale on Audiogon. According to the seller, the retail price is $1,899.00.   https://app.audiogon.com/listings/da-converters-teac-ud-503-dac-this-isnt-even-in-stores-yet-2015-08-30-digital-l2m-4c7

Hello,   I'm looking to buy something good for my Sennheiser HD600. My PC is my only source and currently the Headphones are connected to the onboard sound of my ASUS Z77 Sabertooth Mainboard, this is not optimal and I want to change it. I'm no expert and my knowledge is limited.   The new...