Disclaimer: I met up with Jack Wu at High End in Munich just last month and at the end of the show he allowed us to take one of the units that were present at the show with us for review. Big thanks!
It wasn’t that long ago that I featured the gorgeous WA2 in our Picture Post series and during my stay in San Francisco I fell in love again when my friend was so kind to get his WA22 out of storage and unbox it for me. I obviously have a love-hate relationship with Woo Audio, it’s actually more of a love relationship as I like almost all of their amps. Almost, except for one: the WA7 Fireflies. It just doesn’t do “it” for me but so many other it does. Must be me.
According to Woo Audio, the WA8 is the world’s first battery-operated vacuum tube amplifier with DAC. I guess it all depends on how you look at things but some of Woo’s colleagues don’t really agree with that statement. Do I care if it’s the first or the sixth amp? Not really, I care more about how it sounds and I wouldn’t worry about who was first.
The Woo WA8 is a transportable DAC and amplifier combo that delivers a desktop quality sound. While we’ve said that before, I have to admit that the WA8 is doing so on a whole other level. If you would let ten people listen to the WA8 without telling them it was a small transportable tube amp(/dac), at least eight would think it was a full sized desktop unit. And a good one for that matter. Also one that powers anything in my collection, from the dynamics to the orthos, 8 to 600Ohm, IEMs or full sized headphones: everything goes just as good and just as easily. Woo calls it: “The most compact high power all-tube amp”. The WA8 however isn’t a portable unit but Woo never claimed so and they even advise against using it in closed bags and back packs. With its 1.1kg it’s a bit heavy for on the go anyway.
The DAC inside the WA8 only accepts USB(2.0) but it does so all the way up to 24bit/384kHz. Before I saw the specs of the WA8 I was afraid the DAC-chip wouldn’t be the best but I was very happy to see Woo chose the ESS Sabre ES9018K2M, a very popular and top quality chip I happen to like. In order for it to work you have to install a special driver on Windows operated pcs, but getting it to work in Foobar2000 over ASIO was extremely easy. The USB receiving chipset in the WA8 is the XMOS xCore. While the WA8 officially doesn’t support DSD, I have managed to get DSD working over DoP
Next to that the WA8 has one 3.5mm (1/8″) analog input that of course bypasses the WA8’s DAC circuit (the line-in has priority over the USB-in). The WA8’ amplifier uses one matched pair of 6S31B and one 6021 subminiature tubes. (Just like the ALO CM but more on that later). You can either choose to run on two or all three tubes. It’s a sort of gain switch but it has quite the impact on the sound as well. Most of these miniature tubes are calculated to have a 10.000 hour lifespan but Woo rates them at 5.000h of life. Unlike the CDM where tube rolling is extremely easy, the tubes in the WA8 are harder to replace. The tube compartment can be replaced when one of your tubes pops, but you have to buy a new module from Woo Audio and they’ll send it to you together with the “how to” manual.
Battery wise the WA8 uses a Rechargeable 3400mAh Lithium-ion battery but that won’t give you more than 3 to max 4 hours of playtime. I know this isn’t a lot but again, this shouldn’t be used as a portable unit. Mine is plugged it most of the time. When charging the unit while it’s in use, the casing gets very hot, it is a Class A amp (Transformer coupled) after all. Some people were complaining about the ALO CDM running hot, but the Eclipse unfortunately gets just as hot. The Eclipse operates via external DC power or “off-the-grid” battery operation. Advanced technology provides steady and pristine power to the vacuum tubes and the DAC. So even when the WA8 is charging, the power is drawn from the batteries for “cleaner” power.
The eclipse comes delivered with a 12.6v premium quick battery charger, a USB 2.0 cable and a Pelican carrying case with custom foam inserts to provide maximum protection. I love the case and it protects the gorgeous WA8 on my daily trip to work and back home like no other. (water-resistant, crush-proof and dust-proof)
The normal Woo Audio WA8 goes for $1799
Looks & Build
We all know Woo makes gorgeous amplifiers and their build quality is one of the very best. I haven’t seen a single Woo amp that wasn’t perfect. In fact one batch of WA8’s was only very recently postponed as Woo didn’t consider the cases to be up to their level. Bad news for the waiting clients but I fully admire Woo for doing that.
My review unit has been used during several shows and it has a light scratch on the back but apart from that it’s perfect. Every connector, seem or switch on the WA8 fits perfectly and the volume button is so very smooth to turn. On the front of the unit on the left side you’ll find the battery level indicator (5 mini LEDs) but the most attention is drawn to the three tubes that are safely stored away behind a 5cm wide glass compartment on the right. On the right side of the unit you’ll find one 3.5mm SE headphone output and a 6.3mm output. No there’s no balanced. On the left side of the unit you’ll find the power switch, the USB input and the analogue input. On top you have the selector and the ventilation for the tubes. On the back of the unit there’s nothing to see and on the bottom there are two thin rubberish feet so that the case won’t scratch the table. Or is it the other way around?
I mentioned before that the Eclipse is heavy and it really is compared to the portable gear you’re used to. But as you shouldn’t see this as a portable unit but a transportable one, the weight actually is quite ok. I take it home with me each day after work and sure my bag is a little heavier (1.1kg) but it doesn’t bother me one bit. Even while doing it daily, taking the WA8 out of its sleeping place is magical. The unit just oozes quality, the case feels smooth and turning volume button is a pure pleasure. Precise and smooth, just how I like it.
There are a few things I want to point out before you start using your WA8. When you power the WA8 on and off there will be a pop, it’s that simple. The loudness of the pop will depend on the headphone connected and the volume it is set at. I fully advise removing your headphone before you turn it off and after you turn it on. Drivers are safe, ears are safe. All is good. Before you plug your headphone in or out you also have to make sure the volume is set to zero. And before you switch from two to three tubes or back, you must turn off the unit as the circuit needs to reset. I’m repeating this because there are people who obviously didn’t do all that and then complain afterwards. So be warned.
Sound, on page two, after the click
All-tube design (not hybrid)
Class-A, Single-ended Triode transformer-coupled
Tubes 6S31B x2, 6021 x1
Selectable two- or three-tube operation
In-house Nickel core, OCC Single Crystal Copper output transformer
Frequency response: 20Hz – 30kHz, -3dB
Max headphone output 350mW
ESS SABRE Reference DAC (ES9018K2M)
XMOS xCORE-AUDIO asynchronous USB compatible with Mac, PC, Android and iOS devices
Hi-res music playback up to 24-bit/384kHz
USB (Type-B) digital input, and 1/8″ (3.5mm) analog input
1/4” (6.3mm) and 1/8” (3.5mm) headphone outputs (8-600 Ohms)
Up to 4 hours of battery playtime, 3400mAh rechargeable Lithium-ion battery
Five LED battery indicators
CNC-milled aluminum enclosure, available in anodized black, space gray, and gold
Dimension 6.69″ (L) x 3.6″ (W) x 1.69″ (D) / 170mm (L) x 92mm (W) x 43mm (D)
Weight (amp) 2.4lbs / 1.09kg
250mW @32Ω 350mW @50Ω 180mW @120Ω 120mW @300Ω 80mW @600Ω (3-tube operation)
Sound, on page two, after the click