The Topping TP30 is both an external USB sound-card and high quality mini amplifier based on the popular Tripath 2024C chip. Ideal for multimedia (USB-DAC) sound applications, desktop speakers, background music, ceiling, or in-wall speakers.
I own one of the TP-30 amp/dacs. I originally purchased it to power a pair of dayton b652 bookshelf speakers. Well, the speakers did not sound good to me, so I purchased a pair of Pioneer BS22 lr bookshelf speakers. Now, I think they sound much better. But, the TP30 was not as powerful as I needed it to be. So, I am now using it in it's DAC capacity.
I own the following phones: Grado SR80, Sony MDR-V6 and Shure SE530 IEM's. All three sound fine to me being powered by the tp30. Much better then they sounded without external amplification in my opinion.
Please feel free to add to this, not only for the tp30, but the aforementioned phones as well.