The D2 is an extremely versatile player and should drive any type of phone well. I use it with the 325's (they're 32 ohms) and the two are well matched. I also use the Etymotic er4s, but these are 48ohm monitors, thus they needed an amp.
However, the detail of the Grado's coupled with the detail of the D2 wouldn't be everybody's cup of tea. I do find myself EQing the highs down a fair bit. Suffice-it-to-say this is not a warm combination. But, if you love crisp detail then this is a good choice. They have nice, tight detail in the lower frequencies too I might add.
Last edited by KMASCII; 06-08-2009 at 02:35 PM.