Technology & Appearance
The KWA 100 is ModWright’s entry-level power amplifier. It is a 100 watt @ 8ohm stereo power amplifier, employing a fully discrete, single voltage gain stage circuit that ModWright calls a “Solid State Music Stage” (developed by Alan Kimmel), along with a Mosfet output stage. The design objective for the amplifier was to combine the strengths of both tube and solid stage amplifier designs. According to ModWright, the solid state music stage produces, “3-D sound-staging, holographic imaging, and a beautiful midrange of tubes, combined with sparkling highs, low distortion, bass resolution, and control of solid state.”

Other key features of the KWA 100 amplifier include a high-low bias switch; true balanced floating inputs accepting balanced and unbalanced input connections; a regulated power supply for the input stage; oversized heat sinks; and Class A-B operation, with the first watts of power produced in pure Class A. The KWA 100 also employs no global feedback, is direct-coupled and fully differential. ModWright also proudly states that the KWA 100 is designed and handmade in the USA.

With dimensions of 17” (w) x 17” (d) x 6” (h) the amplifier is not small, but for an amplifier of its size it isn’t tremendously heavy, weighing in at only 47 pounds when fully packed. The review sample came in a newly available, non-glossy black finish, with a prominent ModWright Logo, and engraved company name and model number. The logo lights up with a medium blue hue when the amplifier is powered on.

Performance
The KWA amplifier arrived in mid-December 2010. After a few weeks of non-critical playback, my evaluative listening sessions ended up taking place during the winter holiday. Normally I begin critical listening sessions with the same musical selections, often in the same order. However, having added a few new pieces of vinyl to my collection over the holidays, I began the ModWright KWA 100 amplifier evaluation by listening to some freshly opened records.

First up was Blowing in the Wind, from The Freewheelin’ Bob Dylan; part of Dylan’s recently released The Original Mono Recordings box set. Regular readers of TIE may recall previous references to a Bob Dylan SACD Box Set that was produced a few years back. I’m a big fan of Dylan, and find the work that’s been done re-mastering his recordings over the last decade to be exceptional.

Blowing in the Wind is a gentle and melodic track with just a touch of aggression in both the guitar playing and the harmonica. With the KWA 100 at the core of my system, the new vinyl version came through crystal clear with the intricacies of these new records shining through. Dynamics were strong, the voice and guitar were clear, and the harmonica possessed just the right amount of bite.

After listening to the rest of the songs on side one of The Freewheelin’ Bob Dylan, I jumped between various cuts from the seven other albums in the box set. With all the Dylan records my reaction was consistent; there was an open presentation, coherence, dynamics and a lovely degree of warmth. The ModWright amp brought out the best in this set of records and it was a thoroughly enjoyable first listen.

I followed the Dylan albums with three more newly opened records – Tom Waits’ Mule Variations, The Arcade Fire’s Neon Bible and Nick Drake’s Five Leaves Left. While Drake shares folk similarities with the early Dylan tracks, both the Waits and Arcade Fire albums take you in totally different directions. You know you’re in a different sonic world when Big in Japan, the first cut on Mule Variations kicks in. Its strong dynamics, led by a driving baseline and heavily distorted guitar & voice, should definitely shake the room. In this regard the KWA pushed my ATC SCM 40 loudspeakers pretty hard. But by the time you get to Hold On, the third cut on side one, the room settles down, and you’re left with a gentle bass line and glistening guitar that surrounds a now soulful Waits.

Arcade Fire’s Neon Bible is an aggressive and dark album that never really lets the listener settle in. Its complexity is perfectly exemplified in the final track, My Body is a Cage. While this tune starts gently enough with voice, distant percussion and organ, it willfully builds into a driving, aggressive mixture of symphonic percussion, swirling organ and driving guitar that pushes vocalist Win Butler’s intensity higher and higher. The KWA handled all of these changes well. There was no sense of dynamic compression; the sound in the room built smoothly with the song.

After all the new records had been spun I went back to my old familiar tricks. I brought out a collection of CD tracks I’ve accumulated over the years, all songs that I find to be simultaneously enjoyable and critically revealing, and which collectively offer a cross section of musical genres: folk, rock, blues, jazz, and classical,

Now back in familiar territory I stared to really see what the ModWright was doing well. A real standout from the listening session was a 1995 recording of The Foggy Dew, performed by The Chieftains featuring Sinéad O’Connor, from their album The Long Black Veil. O’Connor gives a stirring performance on a beautifully produced track. A good hi-fi system transports you right into the recording booth with her. With the ModWright it all clicked – dynamics, clarity, space and warmth were all evident.

After a few days of intense listening I developed a fondness for the KWA100. There’s a lovely coherence in this amplifier’s sonic signature. Perhaps it’s related to a well-designed match with Dan’s LS 36.5 pre-amplifier, but I really got the sense that the music holds together. High piano notes are clear with an excellent amount of sustain; bass notes are deep while remaining tight. The midrange is a tad forward in presentation, bringing the music out into the room rather than letting it set back behind the speakers, but that attribute can also be described as revealing, bringing you closer to the center of the song where the meat of the music often exists. Voice, guitar, and piano: these instruments all really shone during my time with the KWA 100.

I had one curious thing happen during my sessions that I think is relevant to point out. The KWA 100 includes a bias switch on the back, with the option to toggle between high bias and low bias. The manual states that the amplifier will operate best in high bias mode, but that it will also draw more power while producing more heat energy. Following its instructions, I started out in high bias mode, but during a second listening session I switched to low bias. Contrary to the manual’s suggestion, I preferred the overall sound with the low bias setting. High frequency detail dropped down a bit, but there was an added warmth and fullness to the music that I found both more pleasing and more accurate. My recommendation after some additional research is to try both settings. With any configuration of hi-fi electronics there are synergies to be found, and for my system, with the KWA 100 driving a very revealing pair of ATC speakers, I preferred the low bias option.

Synopsis and Commentary
I’ve always enjoyed Dan Wright and I have a lot of time for his work in Hi-Fi. That might read like a bias, but in this case the horse definitely came before the cart; I was drawn to the designer and his company after time with the equipment. Like their SWL 9.0 pre-amplifier, ModWright’s KWA 100 power amplifier offers exceptional value to the audio enthusiast, and represents an affordable entry into true high-end audio. ModWright is currently developing a new integrated amplifier to round out their line up, and they have also recently released a new LS 100 tube pre-amplifier, which I would anticipate being an excellent match for the KWA 100 amp. Whether paired with a ModWright amplifier or added to a system alone, the KWA amplifier is highly recommended, without hesitation. 3.5/4 Stars