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The Pace-Car from Empirical Audio changes user-friendly mid-fi sources such as Squeezebox, Sonos and AirPort Express
into world-class digital sources. It allows the audiophile to use the playback software and user interface they like
without sacrificing any sound quality. The Pace-Car can be configured to work with practically ANY digital source.
The Pace-Car does not modify the digital data in any way. What it does is reduce the jitter in the timing to inaudible
levels. Jitter is a phenomenon that has plagued digital audio and CD playback from its inception. It is similar to
"wow and flutter" that occurs with LP turntables. Jitter is a frequency modulation of the music waveform caused by
inaccuracies in the timing, or "clocks". Jitter is typically caused by inaccuracies in the master system clock, but
more jitter can be added as the signal passes through buffers, dividers and even cables. Jitter is even introduced when
the signal is converted to S/PDIF to be transmitted on a coax. The optical conversion of Toslink introduces even more
What the Pace-Car does to minimize this jitter (you can never completely eliminate it), is buffer the data in a FIFO
(First-in, First-out) buffer memory and then clock it out using an ultra-stable clock with a minimum number of low
jitter dividers and buffers. The incoming data jitter does not matter with the Pace-Car. It only needs to store the
data in the FIFO memory. The timing information is discarded. Then new timing is created at the FIFO output. The
output is totally electrically and timing-domain isolated from the input stream. The result is inaudible levels of
jitter on the output.
What you will hear is unprecedented clarity, dynamics and 3-D imaging. This is what is sounds like when the
high-frequency jitter modulation is gone. Even the most expensive CD players have significant audible jitter on the
digital outputs. The Pace-Car can even be configured to work with these.