I would strongly suggest the Chord Hugo which I can vouch works exceptionally well with the HD650, other than that you can look at the A200p from Beyerdynamic. Both are portable but the Hugo is stunning!
Oops sorry Pete321, I'm running the shop one with a vertere too lol. if you want to borrow it your welcome. Not sure on the epiphany miniature as not heard it.
Regards
It has a digital coaxial or USB input, if you need a pre amplifier then that's the Invicta or Invicta Mirus. This little unit sounds in my ears better than the mytek and teac ud501 well worth another 85 over that.
Resonessence have just released their next Concero product in the form of a stunning little DSD capable USB headphone amplifier. This new Headphone Amp uses ESS's latest ES9018-2M chip and offers 2 default filters for user preference. More will be added soon. Featuring a 6.3mm output and 3.5...
Merdian Audio have just announced the Director DAC which follows on from the success of the Explorer. Offering more flexibility with the added extra inputs such as toslink and coaxial the Director also adds Meridians advanced upsampling and apodizing filter which the explorer didn't have.
Seems there is a slight delay on the Blue at the moment but all the other coulours seem to be readily available. Sound wise I prefer these to the B&W P3.
A high quality DAC can really make a massive difference to the Sonos, you could look at the Arcam Sonlink for a "budget" DAC that would make a difference or maybe the Resonessence Concero.
Regards
The TEAC-UD501 is neutral to warm sounding. The balance of sound is excellent and I highly recommend it. The other DAC to look at if you want a very open, detailed, fast and clean sound that sounds more analogue than many DACs I have heard you may want to look at the Concero DSD...