How to Guide
4 Russound P75 Installation Manual
Introduction
The Russound P75 is a 2-channel dual source power amplier with auto-
source switching. It features two audio line inputs with a loop out to another
zone, receiver, or device from the Line 2 source.
The P75 amplier is rated at 75 watts per channel into 4 ohms, and 60 watts
into 8 ohms. With the Stereo/Bridge Mono switch in Bridge Mono position,
both amplier channels are combined for a higher powered mono output. In
Bridge mode the P75 is rated at 160 watts of power into a single 8 ohm load.
Each amplier output channel incorporates robust protection circuitry for
reliability and safety.
Thermal Protection
P75 ampliers is designed with special circuitry to safeguard the amplier
under a thermal overload condition. Thermal protection mode will only engage
when the unit has been run at high volume for extended periods of time
without adequate ventilation and/or when speaker impedances are below the
minimum levels for the amplier. In thermal protection mode the amplier will
automatically stop output. If this fault occurs, turn o the amplier, and check
that the speaker impedance rating is above the minimum rating. Also check for
adequate ventilation around the amplier and make adjustments if necessary.
Once the unit has cooled to safe operating temperatures, the amplier may be
powered back on.
Protection Circuitry
Special circuitry has been designed into the amplier to safeguard under a
short-circuit condition. A faulty speaker can also cause a short circuit condition.
If this fault condition occurs, turn o the amplier and check speakers for short
circuit conditions when appropriate.
Installation
The P75 amplier can be placed on a shelf in an equipment rack, or on a table
or cabinet. Be sure to follow the required clearances shown on page 3 to allow
for ventilation and heat dissipation.
PRODUCT OVERVIEW
Front Panel Controls
On the front panel of the P75 amplier are the power button plus speaker
selector, a master balance and a master volume adjustment.
Power - the front panel switch will manually switch the power on or o.
Power LED indicator - RED = ON, AMBER = Standby,
No Light = Protection Mode
Speaker selector - select speaker pair A (main) or speaker pair B (auxiliary) for
audio output. You can use speakers A and B together, as long as the speakers
are at a minimum 8-ohm impedance.
Balance - adjust speaker output balance between right and left channels. The
default setting is at center.
Volume - adjust the speaker output volume. If using Bridged mode, set the
volume at minimum, then adjust to the desired level.
Unswitched Outlet
The P75 amplier has a built-in outlet on the back panel. This 120 VAC outlet
provides 400W unswitched power for a device such as a small powered
subwoofer. This switch provides power as long as the P75 is plugged into an
outlet, whether or not the unit itself is powered on.
Manual / Auto On
The P75 amplier can be turned on manually or automatically by setting a
switch on the back panel. For manual power on or o, press the Power button
on the front panel. For automatic power on, set the rear switch to Auto On, and
place the front panel power button in the "On" position. When music is sensed
on either input RCA connector, the amplier's signal sensing sends a command
for it to power on. Once the signal ends, the amplier turns o.
Speaker Cable
When connecting speakers to the P75 amplier, use a minimum 16 gauge and
maximum 12 gauge stranded copper cable. Avoid leaving stray strands and
keep polarity consistent.