Specifications

Model 9762 – Dual Combo Owners Manual
5.3 Gain Blocks and Metering
The 9762 provides up to 75 dB maximum gain using a dual gain block
type design. Gain is selectable from –20 dB to -75 dB in 5 dB
increments via the twelve position rotary switch. At higher gain settings
(above -50 dB), a second gain block is inserted into the signal path for
additional gain and increased headroom. The input signal stages are
designed for maximum headroom throughout the audio path at any gain
setting.
The SP (signal present) and OL (overload) LED’s provide input stage
signal monitoring. In normal use the OL should not light to prevent signal
distortion. The signal quality degrades rather quickly once the OL
threshold is reached. The SP and OL LED’s monitor channel activity and
clipping for the signal source currently selected by the DI switch.
The five LED VU meter monitors the master output level from the line
amplifier stage. The first LED lights at –10 dBu with subsequent steps at
–5 dBu, 0 dBu, +3 dBu and +6 dBu. The master LEVEL control is used to
trim the output level using the VU meter as a level reference.
5.4 Line Amplifier Stage
The line amplifier stage input level is controlled by the master LEVEL
control. The LEVEL control acts as a channel fader to trim the line
amplifier output as needed. In general, the LEVEL control should be set
to the maximum position (fully CW) and the input GAIN control is then
adjusted to obtain the desired output signal level. If the output signal is
slightly “hot”, use the LEVEL control to trim the output level back to
obtain the desired output signal level.
In situations where distortion or warmth is desired, the input GAIN setting
may be set “hot” and the output LEVEL control is used to trim the output
back to a suitable level. Use care with this technique to avoid overdriving
the input stage excessively as the signal becomes very ugly sounding at
extremes. Also, keep in mind the line amplifier stage is capable of
delivering very large output level swings (around 40V peak-to-peak!);
excessive signal levels may potentially damage the input stages of gear
being driven by the 9762.
The rear panel unbalanced ¼” line outputs are driven directly from the
line amplifier stage and bypass the output transformer completely. The
balanced XLR output connectors are generally preferred as these may
be used in balanced or unbalanced wiring configurations (refer to Section
4.2). However, the unbalanced connectors provide other options for
interfacing with various types of equipment and gear. Recall that cable
lengths should be kept to a minimum with unbalanced signals and proper
grounding must be paid attention to.
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