Woo Audio WA8 Eclipse
Until recently, one of the most daring things I'd seen on an amp was the large block of glass atop Woo Audio's WA7 Fireflies. The amp, a simple, yet good-sounding transformer-coupled tube amp performed, I reckon, above it's $999 price (ignoring the DAC), and gives an IKEA-like style to the world of headphone amps. That was until Jack Wu decided he was going to make a portable version, the WA8 Elipse.
Let's get the major bits out of the way first: It weighs 1.09 kg or 2.4 lbs. This is purely crazy. The weight isn't just from the battery, it's actually mostly from the case and the two transformers, as the WA8 is not a hybrid. Transistors weigh only a few grams. Transformers weigh a few hundred. But Jack is a purist, and possibly all the better for it. The next thing is the battery life: 4 hours. At least you have 5 LEDs on the side to let you know roughly how much you have left. Once only one light is showing, you have about 10 minutes before the amp will shut itself off.
That makes the amp transportable rather than portable in the most common sense. If you're going to take it to work to listen all day, you'll be charging it at lunch time. You can just leave it plugged in, however, which works just fine. To that end, the WA8 comes by default with a Pelican case, and optionally with a sturdy leather case.
On the positive side is the USB DAC. Powered by the internal battery, and not the USB bus, it uses an ES9018K2M and officially works with PCM music only, but unofficially will work with up to DSD128, if you have a good enough source for it. Since my days of owning the original WA7, where the inbuilt DAC was about on par with the original Audioquest Dragonfly, both the WA7's DAC has been upgraded and Jack delayed the WA8 to get proper performance from the one in the WA8. I was expecting to give the DAC some brief use then switch to either my Schiit Yggdrasil or Chord Mojo, but I was surprised to find myself using it, direct from my computer (rather than via a USB re-clocker like the Schiit Wyrd) and completely satisfied.