works great and very convenient
Arrival and Setup:
I bought the ES100 so that I could use my IEMs more easily with my iPad Pro. I've got USB-C DAC cables, but this seemed simpler and the price was good. It arrives in a small box with foam packing and a short charging cable (microUSB) which is perfect. I charged it before use and the light went from red to green in about 20 mins (figured that meant it was fully charged. I read the quick start guide - pretty useless. Doesn't even tell you how to pair so I had to search that out on the web. Basically once you turn it on, if it hasn't been paired previously, it will go into pairing mode (the green light is blinking). Straightforward pairing from my iPad on bluetooth.
I inserted my IMR Rah with a 2.5mm jack; it took a bit of pressure but went in fine. The Rah is normally connected to balanced output from Cavalli tube hybrid playing variety of sources from HD music to Spotify. Mostly classical and vocal. The ES100 DAC isn't bad; I had no problems listening with it, just not as open or detailed as from the Cavalli. Not complaining; I was perfectly happy listening to music using the ES100 for an afternoon. Seems to be a bit of burn-in required, as the sound seems to improve, but that could just be me getting used to it :-)
The quick start guide needs a link to the full manual online. Otherwise what the colours and blinking lights mean is a bit difficult to decipher.
Clip is useful but isn't tight enough - moves as I use it.
I think I ran out of power after a few hours (wasn't measuring) and plugged the ES100 into a powerbank. Bluetooth and music went intermittent after that. Lights would flash (no idea what they mean) and I would lose music, then it comes back on. Gave up and just let it charge.
Different (not better; not worse) than using a variety of USB-C DAC cables and adaptors (I've got a bunch of those) to the same IEMs. Will likely try them with other IEMs and maybe even fullsize headphones later. But it does what it's supposed to do, and I like them.
Would recommend to a friend.