Well, that’s a bummer. I’ve been having so much trouble with play/wiggle in the Lightning port that I had been counting on USB-C to address on my next phone. I was hoping I’d be able to focus on something other than the data cable…I should have known better. Thanks for the heads up!
Meanwhile, getting ready for some quality time tonight with the W4 and the IEMs… 
Hello everyone! I m new into hifi and I have 2 questions for now. 1. Can the Luxury & Precision W4 drive the HIFIMAN Edition XV ? 2. What specs should I read/search for to answer this kind of questions myself? lol
I don’t know, but would guess it would be fine in balanced mode.
Anything that is driven by usb power from a limited source or supply will have similar limitations. Some modern devices may be able to draw a bit more power if the usb can deliver it.
Portable devices that have an internal battery may have more power and heavy devices that plug into wall power won’t be as limited.
Someone please point to @Torq’s table of power requirements.
Sometimes you need to balance your requirements between performance and portability.
Yes, with headroom to spare.
You need to know the impedance and sensitivity of the headphone. That’ll let you calculate what’s needed to drive it in terms of voltage, amperage and power (wattage).
And then the power output of the amp or DAC/amp into the closest impedance specified to that of your headphones. Allow 20 dB of headroom for musical peaks.
All of this means you’re going to need to understand Ohm’s law, the Decibel scale (logarithmic), and do a little math.
I should add that, per this post, that tool will probably go offline when it comes time to renew the domain. That’s several months away, but after that it’ll be offline.
You can, of course, download the desktop version* and use it locally, or you can pull the source and you update the data files for it (there was never enough data involved to require an actual database, so it’s all just in JSON files) and then rebuild the package, if you want to add other amps, DAC/amp or headphones - since the W4 is not in the current data set.
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*There’s a pre-built, signed and notarized, macOS build there - if you want it for Linux or Windows you’ll need to run an appropriate build yourself.