I have listened to the E7 EE extensively and tried it as a source with everything over the last few weeks. I listened to it extensively with my own Aroma Audio Jewel and Fugaku, and have heard it with a variety of other IEMs at CanJam including Forte Ears's Macbeth, UM's Nuit Etoile, PMG Audio's APX SE, and countless others.
One common thread united all these listening experiences. The E7 EE sounds unbelievably detailed, spacious, and natural, and this experience was mirrored whether listening to local files on the microSD card, via USB DAC mode, or even on Bluetooth.
This is the most detailed and analog Delta-Sigma chip-based DAP I have ever tried, and it features verious tuning profiles and user-customizable EQ profiles to further tailor the listening experience to the listener. This is all on top of Luxury & Precision's tuning expertise. The sound is never boring, instead creating a large sense of space and highlighting the vocals. This is the ideal DAP for anyone who craves the last ounce of enjoyment from vocal music.