International CES -
Inside the Chassis of CES
David Ranada
January 2002
Panasonic SA-XR10 |
Keeping it Real
To me so far -- and I've only seen a small fraction of the exhibits -- this year's
Consumer Electronics Show has been one mainly of trends and imminent breakthroughs.
Only a few actual, available products have piqued my engineering interest compared
to the number of product prototypes and promising and truly exciting near-future
technologies I've seen. One of the more intriguing and real, available-for-purchase
products I've come across was the Panasonic SA-XR10 ($599, July). Compared to
everything else that was happening in the truly massive Panasonic booth, this
device, a multichannel receiver, was little heralded. It didn't even merit a picture
in the Panasonic press kit CD-ROM (I took our picture). But its rated 5 x 100
watts per channel power output from an enclosure little bigger than a laptop computer
was surprising. This was possible due to its use of extremely electrically efficient
"1-bit" digital amplifiers (controlled by Texas Instruments chips),
which enable high output power ratings with neither a bulky and heavy power supply
nor with massive and expensive heat sinks. One-bit amplifier technology seems
to be taking off in Japan, where an industry consortium has been formed to promote
its use. We are at the beginning stages of a one-bit onslaught.
Yamaha 1-bit power amplifier prototype |
Yamaha was showing a prototype of a one-bit power amplifier and Sharp was again
exhibiting its one-bit technology that's now a couple of years old. Sharp's twist
this time was that they were feeding, through a proprietary and copy-protected
interface, one-bit data from an SACD player directly into their amps. The SACD
data didn't drive the speakers directly, however, but had to be converted to the
Sharp output-modulation scheme first. I was amused -- and annoyed -- by the presenter
in Sharp's booth who restated the old canard that the 1-bit resampling rates employed
(5.6 MHz, 128 times the CD sampling rate) ensure a more accurate reproduction
of the signal (which, on the contrary, is limited by the original sampling rate).
His talk of "limitless fidelity" was definitely overstating the case
as was his showing of the now-standard -- and thoroughly misleading -- waveform
graph showing how many more "data" points are handled by the high sampling
rate. Someday I'll take such cant up in my column.
