[BaboonGuy]

Sell everything and get JH-13, which by all accounts still sounds really great unamped. And then it will scale well with any amp you get in the future. Gogogogogo! They didn't call it a game-changer for nothing.

 

[Ypoknons]

I can't answer that question for you. The question is: are you unhappy with your K701 and other headphones? If yes, maybe HD650 will fix your problems. If you're fine with them, get that DAC/Amp.

 

[Superpredator]

I'm not going to vote, but I'd rather have an HD650 + Darkvoice 336/332 variant than a K701 + M^3. And I like the K701 quite a bit. IMO an HD650 or HD600 make a much better starter set of phones because there are so many entry-level amps voiced for them it'd be hard to get a truly bad combination. I listened to around ten amps before I settled on one I was truly happy with for K701 listening. With the HD650 it took me only two or three.

If you're interested, I reviewed the K701 with a few amps (including the M^3) here. I'm sure there are tons of other reviews here, though research can be a little difficult for very popular headphones.