With the HD650 you could match it with an OTL tube headphone amp.
Woo Audio WA2. Feliks Elise.
With solid state you are listening to music. With tubes you are enjoying music.
Advice needed for upgrade path
I need some advice on how to proceed with a HP system upgrade. It's for a second home, a condo, where a good 2-channel speaker system just isn't practical. In 5 years or so my wife and I will downsize and the condo HP system will then be it for critical listening. I currently have a set of HD650s. For the interim I could simply buy a used Naim Uniti Atom HE and enjoy that with the Senn's until the dreaded downsizing. Or I could start to put together a HP system for critical listening. How to start, though? Maybe get the Naim and a couple of mid-priced used cans from TMR. Take my time listening to a few different brands like Audeze, ZMF and Meze. I've visited the HP room at Axpona the last two years but just did not find that setting helpful. And then there are amps, days and streamers. My head hurts at the options. Suggestions? Thanks.