Specifications

page 21
Studio Reference I & II Professional Studio Amplifiers
Operation Manual
4 Advanced Features
and Options
Figure 4.4 Input Sensitivity and Ground Lift Switches
4.4.3 Ground Lift Switch
The ground lift switch located on the back panel can
provide isolation between the phone jack input
grounds and the AC (chassis) ground. It does not
affect the PIP module’s input connectors. Slide the
switch to the left to isolate or “lift” the grounds.
Note: The noninverted and inverted signal lines for
the PIP module are connected in parallel with the
corresponding lines of the phone jack inputs. The
input signal grounds are not paralleled. Specifically,
XLR pins 2 and 3 are connected in parallel with the
tip and ring of the corresponding phone jack. How-
ever, pin 1 of the XLR is not connected in parallel
with the sleeve of the phone jack. This makes it pos-
sible for a PIP module to handle its own signal
grounds independently.
The amplifier’s circuit breaker protects the power
supplies from overload. The breaker’s reset switch is
located on the back panel. Facing the back panel,
move the reset switch the left to disconnect power to
the power supplies, or to the right to reconnect
power. If the circuit breaker trips, the front panel
enable indicator will turn off. If this occurs, turn off
the enable switch, flip the reset switch to the right
(on), and then turn the enable switch back on. If it
trips again or the amplifier does not operate prop-
erly, contact an authorized service center or Crown’s
Technical Support Group.
4.4.4 Input Sensitivity Switch
The input sensitivity switch is located inside the
amplifier’s PIP compartment. It is factory-set to a
fixed voltage gain of 26 dB. For standard 1 kHz
power into 8 ohms, this is equivalent to an input
sensitivity of 4.0 volts for the Studio Reference I and
2.7 volts for the Studio Reference II. If needed, it can
be switched to a sensitivity of 0.775 or 1.4 volts.
Here is the procedure:
1. Turn off the amplifier and disconnect the power
cord from the receptacle.
2. Remove the PIP module.
3. Locate the access hole for the sensitivity switch
inside the chassis opening (see Figure 4.4).
4. Set the switch to the desired position noted on
the access hole label.
5. Replace the PIP module and restore power.
4.5 PIP Modules
Versatile PIP (Programmable Input Processor) and
PIP2 modules provide flexible expansion features
that can be added to customize the amplifier. The
modules plug into the connector inside the back
panel of the amplifier. The modules are available
with features ranging from error-driven compres-
sors/limiters to crossovers to IQ
®
control. Visit the
Crown website at www.crownaudio.com, or contact
Crown Customer Service, for descriptions of avail-
able PIP and PIP2 modules.