A little over a month ago, I contacted Jack Wu and asked him I would be able to audition one of his amps. I was happy to find out that he actually had a demonstration Woo Audio 5 that he’d be willing to ship to me. You don’t need to be around head-fi’s forums for more than a day to know that Woo Audio is one of the most beloved companies of tube headphone amps. And yet up until this point, I had never owned a Woo Audio amp. Aside from the adoration, I’m very appreciative of their clean and user friendly website. I’ve always thought (though from a far) that the looks of the amp line were a step above most brands without being flashy. But meanwhile I had never heard any of Woo Audio’s amplifiers on my home rig. So yes, I was extremely excited and eager to get the amp into my home.
I will name the high quality amps which I have spent a lot of time with in my home for a point of reference:
TTVJ Millett 307a
Single Power SDS XLR (I owned it for a very brief time and I was one of the unlucky ones who sent the amp back for repair and never heard it again)
SOURCE: MSB Platinum DAC III
Keep in mind that each amp listed above has tremendous strengths and reason for praise. Also keep in mind that each amp listed above is a tube amp. So where does that leave the Woo Audio 5?
For me, the Woo Audio 5 is the best buy in the market of high end tube headphone amplifiers. It can power any headphone and it can power any headphone well. It has a beautiful lush sound but it is exceptionally detailed without being harsh in the treble region. This (not LE) version also functions as speaker amp (an attribute which I have not yet tested). The version I was loaned is a stock version with Teflon tube sockets and I have been using the stock tubes except for the preferred Sofia Electric 300b tubes.
What I noticed instantaneously after powering the amplifier was that the mids (and particularly the upper mids) were presented in such a way that was extremely beneficial to many of the flagships released in present times (ie Sennheiser HD800 and Beyerdynamic T1. Specifically, the mids had great depth and a feeling I would call round and extended openness. Now that is just a self-invented expression which if I were to clarify I would say imagine the bass to be rock you throw in a body of water. The ripples of this action can distort very quickly if there is any sort of current or activity. With the Woo it felt that midrange was extremely open and well connected to the bass, even more so than most amps. The treble region was exactly as I had wanted it. On the scale between extremely bright and extremely warm, the treble was slightly closer to the warm side. This is an attribute I think serves an amp which has an openly and eve midrange. Sometimes I have found amps add a tad extra treble to clean up the clutter of the bass and mids. This is clearly not necessary with the Woo Audio 5. While I would call the amp warm, it is not slow, but rather rich and beautiful. The amp is dead quiet when matched with the appropriate impedance level to each headphone. The HE-6 is unbelievable out of this amp! The K1000….a sinch for this amp. But what really blew me away were the HD800 and T1s out of this amp. They were beautifully lush and not harsh as they can often sound on a different system.
No review is complete without some criticisms, but let me tell you there really aren’t that many and none are substantial enough to not call this a top contender.
One thing I think would really benefit the amp would be to have balanced ins added to the back panel and a way to use the 4 pin jack for any headphone per the user’s choice. Conversely, I do prefer the HD800 in SE mode (for most music) over the 307a in balanced mode! The 307a has long been my favorite amp, and with many headphones, it still has this title for me. But the HD800 with the Woo was on the level of just about any system I’ve heard.
In terms of sound quality, I have nearly nothing critical to suggest. If I were to nitpick it would be that with some headphones I preferred a more spread-out soundstage presentation. But in its own way, this is not at all a criticism. The Woo’s soundstage is very unique and very rounded. For T1, HD800 and K701 (headphones which already suggest what some would call a over-compensative soundstage) the Woo’s well defined center and rounded soundstage was my preference. I found the HE-6 to have a perfect tonal balance on the Woo Audio 5, but I preferred what I perceived as a wider spread of sound on the 307a for this headphone. I also primarily use this headphone for classical which could add to this preference.
I’m sure some will ask me to compare the other amps I’ve had time with to the Woo, but I will (for now) continue to focus solely on the 307a since it was the only amp I had side by side. As I’ve said there are some headphones I prefer on the Woo, and some that I prefer on 307a. Which is a better amp all the way round? I do not know how to answer this because it depends what headphone you are running. The 307a (which I am using for comparison because it’s the only amp I’ve had in my possession while listening to the Woo) has a more expansive soundstage and an even quicker transient response. But unlike the Woo, it doesn’t have quite the intimate feel or the close-up immediacy of the Woo’s midrange. Both amps do different things extremely well. Keep in mind also, that the 307a has balanced inputs and outputs and that is a feature, which separates it from the Woo. Simultaneously, an amp which is single ended and better suited to my/your personal tastes of a headphone’s needs will do better than a balanced amp which is not suited to a headphone’s signature.
If you’re like me, you feel that many flagships to debut recently in the dynamic-headphone category are bright and need to be tamed by an amp that presents a euphonic sound instead of neutral sound. For me the Woo is a euphonic audio component. It is exactly what I was looking for at a wonderful price.
While this amp has been around for a while, it is new to me and I can only say that it does what it does exceptionally well and for me, I consider that a bargain!
And the best compliment I can give the amp is that I have purchased it.