Ouch!
Sydney Morning Herald
Monday July 10, 2000
One look at the price should tell you that this is no ordinary amplifier. Sharp's new SM-SX100 costs more than many new cars and, with a one-year guarantee, doesn't even offer the same level of warranty protection. The reason? This is at the cutting edge of audio technology - one of the first high-power digital amplifiers capable of reproducing the entire audio spectrum, from 20 Hertz (Hz) to 20 kilohertz (kHz).
Digital amplifiers have been available for several years but have been able to amplify only low bass frequencies, between 20 and 200Hz, so the SM-SX100 represents a real breakthrough for Sharp Corporation. The operating principle is fairly straightforward. A conventional amplifier takes the half-volt or so of analog output from your CD player and uses it to modulate a much higher voltage, creating a wave form that, although it alternates between about plus or minus 20 volts, is otherwise an exact analog of the input signal.
In this Sharp digital amplifier, the analog voltage from the CD player is converted to a simple digital code, or bitstream, consisting of only zeros and ones. Because the digital code is so basic, 2.8 million zeros and ones are required to describe just a single second's worth of sound. This bitstream then directly controls a voltage source that in turn provides power to your loudspeakers. Digital amplifiers are capable of generating less background noise than conventional amplifiers, produce much less heat, and can be made virtually indestructible.
Sharp has spared no expense in the SM-SX100's design. The chassis is a futuristic combination of stainless steel and black plastic and all electrical inputs and outputs are gold plated. Both optical input standards (Toslink and ST Line) are fitted, as is a Direct Stream Digital (DSD) input, to accommodate the digital output from a Super-Audio CD player. There are also balanced inputs to suit high-end audio CD players. Speaker output terminals are state-of-the-art WBT types, set up for bi-wiring. The rotary volume control has no markings. Instead, an LED display shows volume level as a number between 0 and 128. Although the SM-SX100 has seven inputs, it lacks both a record/play loop and a phono input, so if you want to use a CD recorder or a turntable you'll need to connect additional equipment.
The sound of the SM-SX100 shows the significance of Sharp's achievement. First, because it's digital, it's impossible to overdrive. This amplifier sounds as clean at its maximum output power of 100 watts per channel as it does when idling at a few milliwatts. The separation between left and right channels is also excellent - superior to analog stereo amplifiers using conventional circuitry. Neither hiss nor hum is audible, even at high volume levels, and the amplifier always runs cool to the touch.
The beauty of digital technology is that it's not inherently expensive, which means the cost of manufacturing can fall very swiftly. Now that wide-band digital amplifiers are finally available, it's only a matter of time before they become affordable.
INFOFILE
Sharp SM-SX100 Digital Amplifier
Price: $25,000
Distributor: Sharp Corporation
1 Huntingwood Drive, Huntingwood, NSW, 2148
(02) 9830 4600
customercare@sharp.net.au
www.sharp.net.au
© 2000 Sydney Morning Herald