ADC1 Instruction Manual Page 19
Is it possible to eliminate all of the effects of jitter in an entire digital audio system? Interface jitter will accumulate throughout
even the most carefully designed digital audio
system. Fortunately, interface jitter can only
degrade digital audio if it affects the sampling
circuit in an analog-to-digital or analog-to-
digital converter. Any attempt to cure jitter
outside of an ADC or DAC will prove
expensive and, at best, will only partially
reduce jitter-induced artifacts. Dedicated
clock signals (word clock, and super clock,
etc.) are often distributed to A/D converters
and D/A converters in an attempt to reduce
jitter. Again, these are only partial solutions
because jitter even accumulates in these
clock distribution systems. Furthermore, a
poor quality master clock generator can
degrade the performance of the entire system
(if converter performance is dependent upon
reference clock quality. Jitter free ADCs and
DACs are the only true insurance against the
ill effects of jitter. UltraLock converters are
jitter immune under all operating conditions
(they will never add audible jitter induced
artifacts to an audio signal).
What UltraLock converters cannot do UltraLock converters cannot undo damage
that has already been done. If an ADC with a
jitter problem was used to create a digital
audio signal, then there is nothing that can be
done to remove the damage. Jitter-induced
sidebands are extremely complex and cannot
be removed with any existing audio device. It
is therefore important to attack jitter at both
ends of the audio chain. The ADC1 is a great
start, as it will allow accurate assessment of
various A/D converters. It is impossible to
evaluate ADC performance without a good
DAC. The consistent performance delivered by
the ADC1 eliminates one major variable:
jitter.