Sure, but keep in mind I’m pretty deep in this hobby XD
At home, I use a Sennheiser HDV 820 for all my headphones. Very dynamic and really good with any style of headphone signature I’ve thrown at it, and more than plenty powerful enough that I don’t hit any limits with regards to headroom. This means, as an amp/DAC, it basically brings out the full performance of most headphones (unless I want to buy a super super high end DAC) while being neutral enough that I can actually get a great feel for the headphone’s “natural” response.
On the go, there’s something really exciting and addicting about the HD 650 paired with my FiiO X7 (first generation) DAP with an AM2A amp module. I often let people try out the HD 650 with the headphone jack in their phone, and that is enough for people to lose their earginity. The response is usually “Wow, this is so different from $300 Beats/$30 Sony,” but then I make them try the same song on my X7, and that’s when I know I won’t get back the headphones for a few minutes :D
The HD 650 generally sounds detailed but dull and “flat” like a soda without the fizz on most smartphones, same with cheap amps with about as much output power as smartphones. The phones usually fair better than laptops and most desktop computer headphone jacks too. They respond best to amps that are a bit punchy with good dynamics between loud and soft, but essentially they’re not picky once you have a powerful enough amp. I like my HD 650 on my Cavalli Liquid Carbon, PS Audio Sprout II, Creative Sound Blaster X7, Yamaha home theater receiver, Chord Mojo... the list goes on and on. For the price and convenience, I was even impressed with the little Bluewave GET (recently on Massdrop), which sounded better than my iPhone 6S’s headphone jack despite being a little Bluetooth receiver/DAC/Amp about the size of a BiC lighter.
I used to be into tubes and a good tube amp can have great synergy (there’s that word!) with the HD 650. I’ve read really positive reports of pairing with tube amps from Garage1217, Crack, Schiit, Donald North Audio, Glenn audio... and the list goes on and on. I had a custom single-ended-triode tube hybrid that sounded amazing (and less microphonic) with Russian tubes, but I got annoyed with rolling tubes, changing the bias, interference from WiFi and cellphones, and just in general they’re a bit fussy. The magic is there in nice tube amps, but it’s also in good Solid State amps.