JDS Labs, a small engineering shop near St. Louis, has released a new portable headphone amplifier for pre-order... The C5!
This should be one exceptional little portable amplifier. It has an incredibly low THD and very impressive channel balance at low volumes due to a new digital potentiometer volume control. Check out their blog for more info:
I grabbed one on pre-order, and I'll post a review once I have a good listen. They should start shipping around February 28th. :-)