Universal Audio UAD Plug-Ins ver.7.5 - Manual (Page 28)

UAD Powered Plug-Ins Manual - 28 - Chapter 2: Ampex ATR-102
Cal Level Cal Level automatically sets tape calibration/fluxivity. The Cal Level
setting takes care of the setup one would need to make under equiv-
alent hardware operation, and sets the reference tape/flux level with-
out disturbing the (unity) gain of the plug-in.
To select the Cal Level, click the CAL button to cycle through the avail-
able levels, or click directly on the calibration value label. The active
Cal Level is highlighted in yellow. The default value is +6 dB.
Because Cal Level affects the operating levels in the plug-in, it can be used to
compensate for overly high (or low) levels at the input of the plug-in. For ex-
ample, if the input is too hot, lowering the Cal Level will reduce the signal level
without changing
Record , which can affect the tape saturation characteristics.
Note: The noise floor is affected by the Cal Level when Noise Enable
( page 33 ) is active.
As tape formulas advanced, their output level increased, thus lowering rela-
tive noise floor. Under normal use, the machine would be calibrated to the
tape’s output level. However, sometimes the machine is under-calibrated to
leave more headroom for a broader sweet spot or to prevent electronics from
clipping. Therefore, one can “go traditional” and calibrate to the recom-
mended levels (
Table 1 ), or select a non-corresponding calibration setting.
As an example, if 456 is the selected Tape Type and when Cal is set at +6
(6 dB higher than the NAB tape standard), the reference flux level is 355
nWb/m (nanoweber per meter) and is 10 dB below the point where THD
reaches 3% (referred to as the maximum operating level). Therefore, with a
1 kHz test tone at –12 dBFS sent to the plug-in, with Tape Type set to 456, Cal
set to +6, and Auto Cal enabled, output levels of the plug-in will match the in-
put level and fluxivity on the tape will be 355 nWb/m.
The tape manufacturer’s recommended calibration settings for each Tape
Type are shown in
Table 1 .
Table 1. Tape Manufacturer’s Recommended Calibration Levels
Tape Type Calibration Flux Level
111 +0 dB 177 nWb/m
35-90 +3 dB 251 nWb/m
250 +3 dB 251 nWb/m