Was mobius in high-res when you did that? Have you tried listening with/without the jitterbug but not knowing if it was there? I put a ton of time into researching these things after that post you referenced was posted, and the main takeaway I found was that there was no effect on the signal coming from the DAC with the addition of a USB 'decrappifier' - anything the decrappifier can do, the DAC can do (and *should* do) - with the exception of really bad quality DACs. This seems to be corroborated by some DAC manufacturers saying that those devices are not needed with their DAC (but take with a grain of salt because PR reasons). The only reviews I could find that were positive of the decrappifiers were those that tended to have reviews that were more positive the more expensive something was. That's not to say there were shilling - I mean from a "if it's expensive it must be good" sort of perspective, so they listen more critically than before and thus hear more details and think it's because of the decrappifier. Any review I saw where it was double-blind (they didn't know if what they were listening to was with the device or not), couldn't find a difference.
THAT SAID: I only found results for "full-fledged" DACs and not for DACs inside a headphone, like mobius. It's possible that to save money, weight, space, dev time, etc, the mobius doesn't do any of that and thus would benefit from a decrappifier. That's why I was asking if you had tried it double-blind, so to speak.
