By Mark Farmer
Amplifier technology has come a long way from the days of Woodstock and using big home amps to power live sound reinforcement systems. Anymore, there is a fight to see which amplifier company can manufacture the best sounding, lightest weight, lowest noise, most features for your purchasing dollar. Crown has been right in the ball game with their own key advancements with the IQ system and offsetting power (wattage) on sides of an amplifier (24x6 and 36x12), or the monster of amps the Crown 10,000. With this in mind, Crown once again set out to surpass others in the forefront of amplifier science and designed the newest in the Crown line, the K2.
Features
The K2 is a very advanced amp in many ways. Foremost this amp has no fan, yes that is correct, no fan. With no fan and a sealed enclosure there is also no need for filters (or cleaning) which also means less damage on the internal electronics and less noise. In the creation of the K2, Crown invented BCA™ which stands for Balanced Current Amplifier, producing one-tenth of the heat most amplifiers produce and twice the output energy of conventional switching amps. The circuitry used in BCA™ allows for higher temperature levels and higher wattage without damaging components. Crown cast the front panel and case out of aluminum to help dissipate the small amount of heat produced. According to the handy manual, in a worse case scenario the amp will produce the heat of two 100 watt light bulbs. Even if this amp did get hot and begin to go thermal the TLC or Thermal Level Control would begin to bring down the output of the amp until either the input is reduced or something was done about air circulation. A pair of red LED’s are provided on the front to alert the user of the amp going into TLC. Also, the greater into TLC the K2 transcends, the brighter the LED’s become. Other protection devices are a slow “soft start” turn on, subsonic filters set below 8Hz and above 30kHz, external 20-amp fuse, DC protection, and even protection from shorted outputs.
So what about power, can it keep up with the competitor, indeed it does, rated to deliver 1250 watts per channel into a two ohm load, 800 watts for 4 ohms, and 475 watts at 8 ohms. These measurements were done with 1kHz and both channels driven receiving a total harmonic distortion of only 0.1% or less. On the bench, signal to noise was very clean with measurements of greater than 100dB below rated power. Damping factors greater than 3,000 between 10Hz and 400Hz, is of the finest I have ever seen on any amp. Frequency response also measures up to the other standards of the K2 embracing the entire spectrum from 20Hz to 20kHz at plus or minus 25dB.
The sensitivity switch, now external, on the rear provides either 1.4 volt or a fixed voltage gain of 26dB.
Weighing in at a mere 38 pounds and fitting into a 19 inch rack space (2 rack spaces) this K2 is also nicely balanced with the majority of the weight on the front rack ears. Setting the amp apart visibly, is the beautifully designed rounded out front panel.
The main power switch (new rocker type), Level 1 and 2 controls, a enable LED, and four pairs of LED’s are recessed into an area on the right with the giant lexan Crown K2 logo on the left.
The three other pairs of independent LED’s watch over signal input (green), the IOC or Input/Output Comparator sensors (yellow) which keep a close eye on distortion by turning on way before distortion is audible. A complicated circuit that analyzes the existent waveforms of the inputs and outputs. And for the first time in 50 years, Crown has included Clip LED’s (orange) to the K2 line for keeping an even closer eye on the amplifier and its status.
In the rear of the K2, Crown has added a few items and not incorporated other ones. Left out of the new amp design is the availability for Crown's slide in devices (cards) like the IQ (computer control), PIP (Programmable Input
Processor). Moved from within the rear of the amp to the outside is the sensitivity switch. The sensitivity switch has been moved from within the rear to the external panel for easier accessibility. One of the best inventive additions ever to an amplifier is the “Y” Input switch, which couples both left and right XLR/1/4” balanced inputs together. In comparison to the Crown Macro Tech series of amps the K2 inputs have been moved far left, the power cable to the center, and the handy five-way binding post outputs kept on the right. The Bridge Output switch is centered up between the XLR inputs next to the “Y” Input switch. Some of most outstanding amp wiring, layouts, diagrams, explanations, and drawings are included inside the best amplifier manual I have ever seen.
In Use
When I took the Crown K2 out of the box, for my burn in period, I set it out in plain sight at a corporate event I was set to provide sound reinforcement for. During set up I noticed a few of the audio visual company employees had gathered around the K2 looking at it with intrigue. I thought, what a great start for reviewing a product that not only attracts crowds but amplifies speakers too. Fortunately I have become very familiar with the Crown line over the years and know the limits and durability of the Crown name.
With this, I set out to test the full range sonic qualities of the K2 verses the Macro Tech Series of amps. I split the amp power on each side of the room with the K2 and a Macro 2400. Each amp channel, powered two pairs of speakers per side, completely separating four speakers hung on each side of the room on different amplifiers. Each speaker was passively crossed over between a 12” midrange/woofer and a 1” horn driver. My first listening involved no equalization with familiar compact discs played at a moderate volume. Some of the definite differences, at first listen, between the two different amplifier types was volume on the K2 side also was a louder, more articulate, and dynamic sounding. I took some time to equalize both sides of the room with a microphone and more familiar music. With a vocal mic in front of the speakers, the sound seemed to exit the cabinet like lightning compared to the K2 powered speakers compared to the Macro Tech side. The horn response was more translucent and the bass response sounding more controlled and harder hitting. This type of bass would be ideal for keeping large low frequency subwoofers in check.
Regarding heat, I left the signal hammering the K2 on for the afternoon, the K2 top was warm to the touch. With more of the K2 amplifiers in a rack, external fans would be needed, especially during the summer in the elements
Summary
Crown has definitely out done themselves creating a new radical looking amp that sounds as superb as it looks. With this new technology, hopefully we can expect Crown to build on the K2 lineup in the future, keeping other major amp manufacturing companies on their toes competing with the fan-less design.
Once again, the pristine highs, dynamic lows of this amp, superb construction, power output, and monitoring LED’s, all make this an amplifier that will set a new standard in amp design and distinction. With a retail price of only $1795.00, let your speakers have this amp for the sound they need.

Mark Farmer is a live sound engineer for Live Technologies in Columbus, Ohio and a regular contributor to Pro Audio Review. Mark can be reached via the Internet at: mixthat@columbus.rr.com

Product Points
Crown K2 Amplifier

PLUS
+Crown quality of design and construction
+Recessed gain knobs, monitor LED’s,
and power switch
+No fan, no filter, no cleaning, no noise
+studio reference sound
MINUS
- No Crown card slots
-AC cord in the middle
of the rear panel (I’m nitpicking here)