Hi
A couple of years ago, a little on the quiet we put out a little dongle called the Headspace. We being Sonneteer. YOu may have read about us between now and then in Stereophile about our amps phonostage and CD players. A couple of decades ago we also had a range called the Bard Wireless range which stirred a few things up back in the day.
Anyway we've gone miniature lately and the Sonneteer Headspace is the current thing. It's a dongle type gizmo that connects between source and headphones/headsets using a 3.5mm jack and we claim that it makes your headphones sound like loudspeakers. So far a lot (not to be confused with A LOT) of people have been using and liking, even loving it. Which is good and bad as our amps sold at $2000+ this thing is barely $35 so we only make pennies. But hey a lot of people are happy.
Love to hear from people who have an opinion on this kind of thing. Some call it a crossfeed. Though we think we've eliminated all the negatives a lot of these circuits have and we've not tagged it onto $1000 headphone amp (well not yet!) So you can try it for the price of a beer (ok maybe two) though in London you'll be lucky!
If the guys at Stereophile want to try a couple please ping me @haiderSonneteer on twitter or @Sonneteerhifi or through our normal emails/ through our site.
https://www.sonneteer.com/blog/sonneteer-headspace-reviews/?v=79cba1185463
Haider