Hi,
We've been testing the Explorer 2 vs 1 on both PC's and MAC here today. We have tried various tracks and file formats (and a number of different headphones B&W, B&O, quick listen to Grado thanks Hector!)
Firstly, there is a marked difference between the Mk1 and Mk2, there is a lot more clarity in busy passages with the Explorer 2, and much better volume control!
We tested iTunes, Spotify Premium and Tidal. After speaking to MHQ you are better off leaving the settings default in the app (rather than trying the settings say in iTunes to 192/24) this way the Explorer 2 performs the up-sampling.
I picked an album available on all 3 to do a perform a direct comparison (Shostakovich Violin Concerto 1/Daniel Hope/BBCSO)
Spotify and iTunes both produce surprisingly good results with the Explorer 2, Tidal was superb - it seems that Tidal is a step ahead, although the interface can be a bit slow to respond.
We are testing more hi-res tracks using a MAC and PC with Jriver, will keep you posted.
Can't wait to test on MQA files in the very near future!
Thanks,
Justin