Hi guys, the KWA 150 power amp is, as some of you know, our newest product and first amplifier to be born from the ModWright stables... The design is pure solid-state, featuring the brilliant and proprietary
Solid State Music StageTM by Alan Kimmel.
The amp was designed with the intent of satisfying both SS and tube amp lovers. The goal was to provide the power, control, extension, detail and bass extension of good SS designs, combined with the 3-D soundstaging, natural midrange and 'live' and natural sound of music that tubes produce so well.
We found that the key to the overall sonic character of the amp was in the input stage. Alan's design here is brilliant and I believe that it DOES provide the strengths of both SS and tube designs. Combined with a high-quality tube-preamp, I feel that the amp provides an incredible, natural and 'live' presentation of any musical event.
I will follow with basic technical specs and then share the first feedback and testimonials from our customers:
Power Ratings:
> 150W into 6 ohms (stereo).
225W into 4 ohms (stereo).
450W into 8 ohms (bridged mono).
650W into 4 ohms (bridged mono).
Bandwidth: 10Hz - 220Khz
Class A/B design with first watts in pure Class A with VERY smooth transition to Class A/B operation.
Design topology:
Mosfet input and BJT output.
Fully balanced/differential.
RCA and XLR inputs, transformer coupled to fully differential input stage,
> 200,000uf total power supply capacitance.
Use of MWI custom capacitors for critical power supply bypasses.
Fully direct-coupled design throughout.
Zero global negative feedback.
TSPTM - Total Silent Protection circuitry:DC input protection, output short-circuit protection and speaker protection, all achieved completely outside of the signal path!
High/Low Bias settings. Best sonics in High Bias. Coolest operation in Low Bias.
This design has been several years in the works and made its first appearance at RMAF 2008.
It also debuted at CES 2009 as bridged monos, driving the FANTASTIC
www.audiomachina.com 'Maestros'.
We are now in production and are working hard to fill pre-orders accounting for over 2/3 of the first production run. We are shipping to domestic dealers and Distributors all over the world. A unit is current in the hands of a reviewer in HK, another reviewer in Australia and we are shipping to Poland, Greece, Singapore, New Zealand, France and others. Reviews are in the works with Dagogo, 6Moons.com and Positive Feedback On-line, just in the U.S. The KWA 150 will be featured on the cover of HiFi Review HK next month I believe.
Some of you are patiently waiting for amps from your dealer/distributor and I apologize for the wait, but each unit is carefully built, tested and evaluated by hand, in the U.S.A. This is by far the most complex and rewarding product that we have designed or produced to date.
Following is some of the first feedback/testimonials that we have received from our customers:
I have never ever heard the level of inner detail, resolution, speed and dynamic impact that this amp is delivering before in my system. At low volumes the sound is so full, so detailed that there is no reason to even crank it up. Simply amazing! - I. Osuagwu, USA, 2.01.09
While I am not a reviewer, I am lucky enough to be one of the first owners of a ModWright Instruments KWA 150. My KWA 150 is being used in stereo mode and driving the mid and ribbon tweeter portions of a pair of Magnepan 3.6/R’s. A pair of Bryston 7B SST’s are driving the bass panels. Pre-amplification is performed by Dan’s SWL9.0SE 'Signature Edition', and my source is a Denon DVD-5900 with tube PS 9.0 modified by Dan several years ago. Five of the 5.1 channels (not the .1) were modified in this universal player, so it is quite unique. A Marchand 2-way electronic crossover separates the frequencies at 280Hz for HP and LP using 24dB slopes. A Velodyne DD-12 (soon to be replaced by a DD-15 in a few days) takes care of sub duties below 40Hz. Power conditioning by Running Springs Audio.
The amplifier’s construction, fit and finish are second to none. The light blue glows emanating from the MW logo power button and top plate add an elegant touch to the overall appearance.
Good clean power is what this amplifier is all about. Just as another reviewer stated, the resolution and detail of this amplifier is incredible. I hear every subtle finger / lip movement and breath. Dynamics and transients are mind blowing. Everything has such natural timbre, and instruments are reproduced with perfect attack and decay. Even with the most complex passages, the KWA 150 has the ability to keep each and every instrument separate while exhibiting perfect control. Every instrument and voice has a well-defined point of origin and excellent dispersion giving a sense of a natural openness and airiness as if the performer or instrument was right there in front of you. The eerie quietness of this amp allows for the details of any selection to be clearly heard.
In my system, the Maggie 3.6/R’s now have limitless borders, as soundstage depth is clearly apparent, and instruments extend way beyond the edges of the speakers. The incredible thing is that the KWA 150 does this with a sense of ease and is able to put out more without strain if needed. While low level volume with this amp is stunning, increasing the volume gives you an even greater sense of “being there.” My wife stated, “It sounds like we’re at the performance.” I have never experienced this with other amps that I’ve owned.
As Dan has stated, this amp gives you the qualities of a tube amp but with SS slam. I completely agree. I am now left breathless and stunned with the music produced from my system and constantly look forward to another toe tapping session. This amp is definitely one of the components that I would hold onto if I had to sell everything else and start fresh in building a new system. If every Maggie planar and electrostatic speaker owner could hear this amp, then they will definitely enjoy their speakers all the more.
Bravo and Congrats. My hats off to both Alan and Dan for producing this work of art and releasing a product with such excellent quality that performs at this high level. It’s even more incredible to offer this amp at its price point, as I would happily pay much more for it. K. Moy - 2.08.09
I am a dyed-in-the-wool tube guy. I bought the KWA-150 as a backup amp that could break in some speakers and for use in a second system I am putting together. Based on the reviews, I figured it would be a good-sounding piece of gear, but never capable of replacing my tube amps. I was completely wrong. This is a lot more than a good amp- it is a great amp. The midrange is excellent, it has firm control of the bass, and the microdynamics are amazing. Whatever it lacks in "tubey-ness", which is not much, it more than makes up for with its other virtues. I may never become a fan of solid state gear, but I am a strong believer in the KWA-150. J. Blackburn - 2.19.2010 I want to thank all of you who support ModWright Instruments and our effort to produce the highest quality AND highest value Audio Equipment for the ultimate enjoyment of music.
Sincerely,
Dan W.