Suspecting the amp section of the Mojo was the bottleneck, I decided to put the mojo into line out and hooked it up to the Burson Soloist, a $1000 MSRP headphone amp. The bass is still better on the Play, but it appears the Soloist really helped the Mojo in opening up the soundstage, and improving the details. Now it's much harder to differentiate which sound is better. It sort of reminds me of when I compared the Mojo to the Conductor Air. Mojo with the Soloist makes the background notes and synth spark/shine/pop. The Play still produces the most lush vocals with all the same details. Just keep in mind Mojo is only competitive after a huge help from the soloist.