Dual Source Power Amplifier: The Russound P125 is a two-channel, dual
source power amplifier with auto-source switching. It features Primary and
Secondary audio line inputs with a loop out to another zone, receiver, or device
from the secondary source. A speaker-level input can be connected and assigned
as either the primary or secondary source. This amplifier can be used for power
upgrades in zones for large speaker selector or volume control systems.
Stereo or Bridged Amplification: The P125 is rated at 125 watts per
channel into 4-ohms, and 80 watts into 8-ohms. With the Stereo/Bridge Mono
switch in the Bridge Mono position, both amplifier channels are combined for a
higher powered mono output. In Bridge mode the P125 is rated at 250 watts of
power into a single 8-ohm load.
Dual Source w/ Auto-Switching: The P125 has
dual source capability. If two sources are used, connect the source you want to
take temporary priority to the Primary input and the other constant source to
the Secondary input. Whenever the primary source becomes active, that signal
will take priority over the distributed audio signal on the secondary line. The
signal is still active on the secondary line but will not be heard, and once the
primary audio signal is muted or turned off the amplifier will automatically
switch back to the secondary audio signal. You can adjust the delay time(3s-15s)
to determine the length of time it takes to switch back to the secondary signal.
Front-Panel & Rear-Panel Controls: On the front-panel of the
P125 are Power, Speaker A/B, Volume, and Tone controls. On the rear-panel are
Stereo/Bridge, and Auto/Trigger/Normal controls.
- Power On/Off +Auto On: The P125 amplifier can be turned
on manually or automatically by setting a switch on the back panel. For
manual power on or off , press the Power button on the front-panel. For
automatic power on, set the 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 amplifier's signal sensing sends a command for it to power
on. Once the signal ends, the amplifier turns off in approximately 4
minutes. To turn the amplifier on remotely, set the switch to Trigger and
connect a 3.5mm minijack cable from the device to the 12V Trigger In on the
- Volume, Level, & Tone Controls: You can adjust the speaker
output volume, as well as adjust speaker output balance between right and
left channels. You can also adjust the the level of the right and left
- Speaker A/B Switch: You can 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.
- Stereo/Bridge (Mono) Modes: In Stereo mode the
amplifier sends separate power and audio signals to the left and right
channels. In Bridge (Mono) mode both the left and right channels are
combined for a higher power mono output; the minimum impedance for the total
load connected to a pair of channels in the bridged mode is 8-ohms.
Stereo RCA Inputs/Outputs: The Russound P125 amplifier
features two stereo analog RCA inputs (Line 1/Line 2) to connect up to two
analog audio devices. There is also a stereo analog RCA output to send the
amplifier's Line 2 input to another zone amplifier.
Binding Post Speaker Terminals: The P125 amplifier is fitted
with eight binding post speaker terminals and can accommodate up to two pair of
speakers. You can power "A" speaker only, "B" speaker only, or both "A & B"
speakers. When driving a single pair of speakers the amplifier can handle 4-ohm
speakers in Stereo mode, or a single 8-ohm speaker in Mono mode. When driving
both "A & B" speakers the amplifier can handle a minimum of 8-ohm speakers. The
binding post terminals will accept bare wire (16-12AWG), pin-connectors, and
banana plugs (single or dual).
Speaker Level Inputs: If you have a source that is only
available as a speaker level signal, connect it to the Speaker Level Input
terminals, using the binding post terminals and observing proper polarity. Only one set of
speaker level inputs can be utilized and assigned by the selector switch. When
using the Speaker Level Input, and it is switched to the Secondary position, the
high-level signal will not pass to the Secondary Line RCA output.
12V Trigger Input/Output: The 12V Trigger In/Out allows the amplifier to be
activated by other devices or to activate other electronics via a 3.5mm minijack
cable, with 100mA current capability.
Protection Circuitry: The Russound P125 dual source power
amplifier employs protection circuitry to safeguard against short circuits and
- Short Circuit Protection: Special circuitry has been
designed into the amplifier to safeguard under a short-circuit condition. A
faulty speaker can also cause a short circuit condition. If this fault
condition occurs, turn off the amplifier and check speakers for short
circuit conditions when appropriate.
- Thermal Protection: The P125 amplifier is designed with
special circuitry to safeguard the amplifier 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
amplifier. In thermal protection mode the amplifier will automatically stop
output. If this fault condition occurs, turn off the amplifier.
Our Product Research Team
At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.