I currently have a Nuforce udac2 hooked up to a topping tp-21, Im using the Beyerdynamic DT 770 pro 250 ohm ,and the AKG K701 as my headphones. FLAC as source. Udac2 : http://www.amazon.com/NuForce-uDAC-2-Black-Digital-Converter/dp/B003Y5FRNS/ref=sr_1_1?s=electronics&ie=UTF8&qid=1358724103&sr=1-1&keywords=udac+2 Tp-21 : http://www.parts-express.com/pe/showdetl.cfm?partnumber=310-310 My question is if it is worth it to upgrade to a schiit modi/magni stack, or to just save up for a bifrost/asgard (year or so from now, college student). Or to just upgrade the DAC to a modi ? How much difference will I notice between the Modi and Udac2 ? I listen to a wide variety of music.