Any improvement over USB?
I think my optical cable is long lost.
Careful here because apparently the Nexus 4 is a little bit picky. You might need a custom kernel even with the E18 (this is just especulation). Flav106 got the E17 working through USB Audio Recorder Pro (not the ideal solution though):
You might wanna wait till there is more information available with the E18.
EDIT: More info:
Initially the E18 draws negligible power. You might want to keep an eye on it better than E17.
So I have an E17/E9 setup right now. I have the LO bypass ticked up (so away from the words) and have been using the EQ settings on the E17 with the E9. I was wondering how I should tweak the volume overall cuz I have the overall macbook volume (which get's placed at max when the USB cable is in), the media player volume, the E17 volume, and the E9 volume. How should I setup all of this?
So it's better to use bypass mode?
I just received an E17 I ordered. Hooked it up to the usb of my macbook pro for listening to my Fidelio X1 and it's unlistenable, there's a lot of distortion. Is there some settings I need to change or is there a burn in period?
There shouldn't be any distortion. I use a PC, so I can't help you with your problem specifically, but I did have issues with my E17 if I left "USB Charge" ON while listening to it. I would get distortion every 10 to 15 minutes and had to reset either my web browser, media or game and reboot my E17 to get the sound back for another 10-15 minutes. Once I turned "USB Charge" OFF, the distortion problem went away.
Now I just charge overnight when the battery gets low.
It sounds like it could be something to do with the audio settings on your MBP. I've had experience with having a lower bit rate setting causing distortion when listening through my E17.