Good morning (depending on your location).
The purpose of this post is to attain some insights into some really good headphone-amps/DAC for the Sennheiser 650 (that are not too big and can be used more as a mobile headphone-amp/DAC).
NOTE: Upon my initial research, I found some headphone-amps that are too bulky or designed for a desktop with tubes that can easily break with constant moving from one location to the next. Also, I don’t have a brand preference because of my need to attain a headphone-amp that is also DAC compatible – so I can hear sound properly as I link the headphone Amp/DAC with my Sennheiser 650 to a UAD Apollo Duo audio interface for mobile mixing/mastering on-the-go.
Upon a simple Google search, I found a couple of DAC headphone amps below:
Schiit (I have no model specific)
DragonFly Red
But I’m not quite sure of the quality and compatibility with the Sennheiser 650, being that this is my first time purchasing a headphone-amp/DAC and I want to make the correct purchase decision the first time around (so, any really good headphone-amp/DAC at any price point will suffice).
I hope the information I provided can provide good enough details to foster a good option about a decent headphone-amp that is DAC compatible to properly power the Sennheiser 650 through the UAD Apollo Duo audio interface.