Bypass Switch and LED
: This switch activates a hard-wire relay bypass system, which allows the
audio signal to pass through the compressor directly from input to output, even when the 160S is
turned off. That is to say that the XLR Pin 2 at the input connector is directly connected to the XLR
Pin 2 at the output connector, and the XLR Pin 3 at the input connector is directly connected to the
XLR Pin 3 at the output connector. When the 160S is in
BYPASS
mode the LED directly above the
Bypass
switch is lit.
Note
:
Bypass mode can be very useful for applications such as
A-B
comparisons, comparing processed signal with
un-processed signal.
Output Gain Control
: This control adjusts the amount of gain in the 160S’s output amplifier stage. The
signal can be attenuated or boosted by a full 20dB relative to a “0” center setting, representing unity
gain. This control is independent of the threshold or compression ratio settings. Because 20dB of gain
can be added at the 160S output, it is possible to cause clipping even when the input level is with-
in the specified range. When the compression ratio is set at a low number, extreme clockwise rota-
tion of the
Output Gain
control could cause the 160S output stage to clip audio program peaks.
Therefore, for normal operation we suggest setting the
Output Gain
control to “0dB” (12 o’clock
position) as a starting postion. Where the circuit fed by the 160S has a high input sensitivity, lower-
ing the output gain setting can avoid the need for an attenuation pad in subsequent equipment.
Pe ak LED
: This LED is located to the left of the
VU Meter
. It is set to light when the signal level at
the output level r27dBu. This represents a headroom measurement of approximately 3dB
before hard clipping will occur, due to the maximum output level of the 160S (+30dBu).
VU Meter
: The custom designed analog meter is made to serve 3 different functions: first, it measures
the amount of input signal presented at the input connector corresponding to its channel. Second, it
measures the output signal at the output connector, after all processing has taken place, including
output gain. Third, it shows the amount of gain reduction being induced into the input signal, mea-
sured after both the compressor settings and limiter settings. Note that the meter, in
INPUT
and
OUT
-
PUT
mode, measures accurately from -30dB to +6dB. There is 17dB between the upper end of the
meter, and the setting at which the
Peak
LED lights. Be aware that while the occasional “pegging”
of the meter will likely not effect the internal dynamics of the 160S, due to its unheard-of dynamic
range (123dB), it is possible that the output signal from the 160S could cause distortion in subsequent
gear, if the output signal stays above the +6dB marking on the meter for an extended period of time.
The dynamic range of the 160S is meant to provide an
extremely
low noise floor at optimum oper-
ating level (“0”dB, which is +4dBu), and to provide protection for the occasional excursion above
the nominal operating range. It was not meant to provide continuous operation in the 17dB of “no-
man’s-land” between the upper end of the analog meter and the setting of the
Peak
LED.
In G
AIN
R
EDUCTION
mode, the meter moves to indicate the amount of gain reduction, in dB, the com-
pressor/limiter settings are imposing on the output signal. When first activated, the meter’s needle
will jump to the “0” mark of the lower scale on the meter (only if there is no gain reduction hap-
pening), indicating “zero gain reduction”, and will move to the left indicating the amount of gain
reduction in the signal level, up to a maximum of 30dB of gain reduction.
13
controls
160S
Operating
