Massdrop edition of Sennheiser 660S headphones?

Anyone else interested in the 660S? I want a pair of open back headphones for use with my iPhone 7 but I’m hesitant to pick up the 6xx’s as their impedance is 300 ohms. Anyone maybe have experience with the same thing? Is the listening volume actually adequate?

May 28, 2018
" Anyone else interested in the 660S? " - Nope
Just posted up a review of the 660S yesterday;
Tells you my impressions of the 660S....maybe it will give you some help. The 58X driver is slightly smaller than the drivers in the 660S. They are improved by amping. A nice portable amp would be a good thing for these.
May 21, 2018
I’d try the 58x. Not too expensive and could be close to what you want.
May 23, 2018
yeah I’m pretty excited to empty my wallet for the sake of excellent audio quality lol
May 24, 2018
🦋 Wallet friend for you
The 660's were a recent release... you won't see a cheaper version for quite some time. If you want the 660's better off waiting on a sale than a collaboration. If they tank from a sales perspective you might see a greater possibility.
May 23, 2018
I own the HD6XX, they do not sound loud enought or "good" when plugged directly to any phone I've tested so far. BUT you can get a cheap small USB DAC/amp like the Zuperdac or Hifime Sabre 9018, plug it to your phone with an OTG adaptor and you're ready to go. Plus, you can also plug the DAC/amp to any PC/tablet/whatever and it'll work too, so you get both portability and desktop listening. And if you eventually decide to upgrade to a dedicated amp, you can always use the DAC/amp just as a DAC to feed the amp, it won't be the best DAC but it'll probably be much better than the average embedded headphone out on most devices.
V20 drives them with no issues IMO. Not my preferred chain as the 6.3mm to 3.5mm adapter I use won't work with my case of choice and I don't use mine in a portable capacity. The Cayin does a better job but that amp is the same price as the V20.