Uv22 Caveats - Apogee AD-1000 Operating Manual

"[The Apogee UV22] rounds out the rough edges of digital. I put material through the UV22 at below –60
dB and you could clearly hear the low-level information. It was much smoother and much more intact".
"The low-level stuff was really nice and smooth."
"The signal with the UV22 was a lot clearer than without."
"The Apogee UV22 is an excellent way to utilize 20-bit A/D conversion and 20-bit signal processing. It
allows you to capture the improvements of 20-bit even on 16-bit formats. Most importantly, it is very musical
sounding; it doesn't change the tonal balance. With the UV22 the 16-bit output sounds very close to the 20-bit
source.
"It's simple to use and sounds great. Bravo!"
"When a 20-bit signal is processed by the UV22, the result is essentially the same as the 20-bit original, and
cleaner than Turbo Bit Mapping".
UV22 Process Caveats
UV22 Encoding is expected to be the final step in the signal chain before the CD mastering device such as the
Sony 1630, etc. No additional process of any kind should be performed on the UV22 processed data or the ben-
efits may be compromised. Other points in the signal chain are possible, but some care must be taken when
applying the process.
Because of the addition of the UV22 signal, it is not recommended to use the UV22 process more than once or
twice on a signal. Multiple passes through the UV22 process could degrade the noise floor of the system in the
upper frequencies.
Experimentation with the Normal and Low settings is recommended for multiple passes. In the Normal mode,
the process has been optimized to capture the greatest amount of detail from the high resolution digital input.
The Normal mode has the added benefit of smoothing out the non-linearity in almost any DAC. Even with 16-
bit sources, the UV22 process gives notably better results on inexpensive DACs. By using the Low setting, less
of the detail is captured. The Low setting maintains respectable performance with a reduction in the UV22
"Energy Clump" of 6 dB. The reduction in energy could be desirable when multiple passes on a signal are per-
formed.
Recordings to be used in a Sample or Sound Effects Disc can be encoded if only pitch shifting upward is to be
used. Pitch shifting downward on processed signals could make the UV22 Energy Clump audible.
At this time we do not recommend UV22 processing on signals that are destined for compression systems such
as the Sony MiniDisc format. The UV22 Process encodes so much detail that it is possible that the compression
algorithms could have adverse effects on UV22 processed material. For this reason, the intricate information
captured by the UV22 process would complicate the lives of MD compression systems. We have not done
extensive listening tests on this yet, but do advise caution. This caveat is not only true for the UV22 process but
for "noise- shaping" systems such as Sony's Super Bit Mapping.
AD-1000 Operating Manual
"UV22 rounds out the rough edges of digital"
—Stephen Marcussen, Precision Mastering, Hollywood
Page 49
—Scott Hull, Masterdisk Corporation, New York
—John Newton, Sound Mirror, Jamaica Plain, MA