Originally Posted by Zorrofox
Thanks for the input Stan. I'm on a Mac but I don't really have the spare USB port I'd need to do it like that. Anyway, you're right. I still wouldn't be able to do it quick enough. There is a significant difference though. The sound from the E18 is definitely more relaxed and it also sounds a bit less in-the-head, if you know what I mean. To be honest I didn't really expect any audible difference at all which is why I've been taken aback. This is interesting.
I've managed to A/B some DACs on a Mac with a USB hub and switching between them using either Vox preferences, or Sound preferences in System Preferences (with a Fiio HS 2 [ http://www.head-fi.org/t/659603/introduction-about-hs2-headphone-signal-switcher ] to switch the output). It worked well enough to convince me that there was a lot less difference between the DACs than I had previously thought. I can't remember how I solved the volume matching problem but I don't recall that it was too difficult. Most likely I set the volume in Sound and used that to switch, which probably compromised each DACs optimum settings, but I obviously didn't feel that it was much of a problem at the time.
Mind you, I've noticed (like you, IIRC) that Vox is noticably warmer than any other music player on my Mac so I'm going to repeat the tests eventually....
BTW, in the end I still chose the ODAC, despite the differences being too small to detect reliably in A/B/Cing (I had 3 DACs to try). Somehow it felt more "satisfying" and less fatiguing when listening for longer spells than I tend to when A/Bing. Not scientific but good enough for me .