Reviewing Process

Build Quality: Draw

Sound Quality: WA7 with Electro Harmonix tubes

Conclusion

Build quality, clean neutral leaning sound with stock tubes, high quality DAC, compact size, versatility due to tube rolling, plenty of power.Heavy, tubes eventually burn out, warm-up time.$1,100 with upgraded tubesI’ve spent a lot of time with the WA7 with a myriad of headphones from the Koss PortaPro to the Sennheiser HD650 while comparing the WA7 to the Oppo HA-1. The comparisons are done using AB testing that’s sighted as well as volume matched by ear. Those who prefer a more rigorous ABX process should look elsewhere. The views held here are nothing more than opinions that I hold based on my experiences.I would like to thank Woo Audio for the loaner for review!I could wax poetically for a few paragraphs about the beautifully crafted aluminum chassis which is stunningly accented by a glass tube protector. I could write for a page about how each input, switch and knob feels secure and is carefully placed to please aesthetically. I could even write about how beautiful the tubes look with the lights off, glistening through the glass with a soft orange glow.I won’t do that though, I am going to cut the crap and state that the WA7 is a $1,000 product that feels like a $1,000 product. The knobs move cleanly with no unnecessary resistance or looseness, the jacks hold the inputs securely and orange glow of the tubes is very eye catching. The WA7’s construction is just as high-quality as the Oppo HA-1, which I consider to be a compliment in every regard. Neither the HA-1 nor the WA7 wins out here, both are built to high standards and are seemingly built to last. Considering that Oppo is a much larger company than Woo Audio, I mean that in the highest regards.I want to note that the WA7 takes up significantly less space than the HA-1, roughly 1/4th less desktop space, though the WA7 takes up more vertical space.I’ve had the WA7 for approximately a month now and I have demoed the unit with a myriad of headphones including the Audio Technica W1000x, the Koss Porta Pro and the Sennheiser HD650. Initially I had planned to have a section for each headphone regarding the qualities of the amps for each, but time and time again I came to the same conclusions. Below are my thoughts on the WA7 in comparison to the Oppo HA-1.I’ve been somewhat of a skeptic in years past about the difference an amp can make when driving headphones. Because of this I’ve gravitated towards neutral solid state amps and have found myself rather happy with the Oppo HA-1. Not only does it offer an abundance of features, but it outputs a solid amount of power cleanly. I had been completely satisfied with the unit until I heard the Woo Audio WA7.The WA7 is a beautiful piece of machinery that, with stock tubes, I find, outputs a slightly cleaner and more controlled sound than the HA-1. This was much to my surprise, but time and time again, with the same tracks back and forth, I’ve found that I find the WA7 offers better control in the lower frequencies, slightly better instrument separation and a slightly brighter and more energetic edge to it. From the HD650 to the W1000x I have to say that in my AB tests I have preferred the WA7 time and time again.Going back and forth comparing the HA-1 to the WA7 with stock tubes was hard sometimes, at times I struggled to find any difference in all honesty. The differences are nuanced, but noticeable. Then I tried the upgraded Electro Harmonix tubes and the nuances were a bit more fleshed out.Compared to the HA-1 I found that the Electro Harmonix tubes improved the margin of difference between the WA7 and HA-1 a bit more than with the stock tubes, making the differences more noticeable with every headphone I demod with it. In comparison to the HA-1, I feel that the Electro Harmonix tubes offer better clarity, control in the lower regions and a slightly brighter edge, much like stock tubes but with the differences a bit more noticeable. I can’t directly compare the tubes but I feel that, in my listening, that the Electro Harmonix tubes were a worthy upgrade as they further highlighted the differences between the two amps.The Woo Audio WA7 has greatly impressed me. Not only has it changed my views as to what a tube amp can accomplish, it has shown me the differences that a different tube can make in the overall sound of the amplifier. In comparison to the Oppo HA-1 I find it hard to recommend one over the other. On one hand the Oppo HA-1 offers more features than the WA7, and on the other hand I feel that the WA7 offers a better sonic experience.At the end of the day I find myself wanting to listen to my headphones through the WA7 more than the HA-1. The WA7 has sounded exceptional with every headphone that I’ve plugged into it from low impedance headphones to high impedance headphones. The WA7 is a beautiful piece of machinery that should not be overlooked by those wanting a high-quality tube amp that works with low impedance headphones as well as it works with high impedance headphones.Come see the full photo set here