Protection Indicator 2; Input Signal Connections; Phono Input - And Ground Connection (Gnd) 0; Line Level Inputs =Qw - Rotel A12MKII Owner's Manual

Stereo integrated amplifier
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Protection Indicator 2

The amplifier has both thermal and over-current protection circuitry that
protects the amplifier against damage in the event of extreme or faulty
operating conditions. The protection circuits are independent of the audio
signal and have no impact on sonic performance. Instead, the protection
circuits monitor the temperature of the output devices and shut down the
amplifier if temperatures exceed safe limits.
Most likely, you will never see this protection circuitry in action. However,
should a faulty condition arise, the amplifier will stop playing and will
display "AMP PROTECTION" on the front panel. The power indicator
on the front panel will turn red.
If this happens, turn the amplifier off. Let it cool down for several minutes,
and attempt to identify and correct the problem that caused the protection
circuitry to engage. When you turn the amplifier back on, the protection
circuit will automatically reset and the power indicator
In most cases, the protection circuitry activates because of a fault condition
such as shorted speaker wires, or inadequate ventilation leading to an
overheating condition. In very rare cases, highly reactive or extremely
low impedance speaker loads could cause the protection circuit to engage.
If the protection circuitry triggers repeatedly and you are unable to isolate
and correct the faulty condition, contact your authorized Rotel dealer for
assistance in troubleshooting.

Input Signal Connections

NOTE: To prevent loud noises that neither you nor your speakers will
appreciate, make sure the system is turned off when you make any
signal connections.

Phono Input - and Ground Connection (GND) 0

See Figure 3
Plug the cable from the turntable into the appropriate left and right phono
inputs. If the turntable has a "ground" wire, connect it to the screw terminal
to the left of the Phono inputs. It will help prevent hum and noise.

Line Level Inputs =qw

See Figure 3
The CD, Tuner, and Aux inputs of the amplifier are "line level" inputs. These
are for connecting components such as CD players or other audio playback
devices with an analog audio output.
The Left and Right channels are labeled and should be connected to the
corresponding channels of the source component. The Left connectors
are white, the Right connectors are red. Use high quality RCA cables for
connecting input source components to the unit. Ask your authorized Rotel
dealer for advice about cables.

Digital Signal Inputs [

See Figure 4
There are two sets of digital inputs labeled 1 and 2 for COAXIAL and
OPTICAL respectively. Connect the COAXIAL or OPTICAL outputs of your
source component into these sockets. The digital signals will be decoded
and played by the amplifier. The unit is capable of decoding PCM signals
up to 24 bit, 192kHz.

Preamp Output p

The amplifier has a set of preamp outputs labeled PRE OUT. The currently
selected source input is available from this output. Typically the PRE OUT
output is used to provide a signal to another integrated amplifier or power
amplifier, which is used to drive remote speakers.
NOTE: Changes to the settings of the Volume, Balance or Tone controls
affect the signal from the Preamp Output.

Speaker Outputs ]\

2
See Figure 3

Speaker Selector Switch 5

The amplifier has two sets of speaker outputs, labeled "SPEAKER A"
2
should turn blue.
"SPEAKER B"
selector buttons

Speaker Selection

If only one set of speakers will be used at any given time, the speakers may
have an impedance as low as 4 ohms. If there are times when both the A
and B speakers will be used, all the speakers should have an impedance
of 8 ohms or more. Speaker impedance ratings are less than precise. In
practice, very few loudspeakers will present any problems for the unit. See
your authorized Rotel dealer if you have any questions.

Speaker Wire Selection

Use insulated two-conductor stranded wire to connect the unit to the speakers.
The size and quality of the wire can have an audible effect on the performance
of the system. Standard speaker wire will work, but can result in lower
output or diminished bass response, particularly over longer distances. In
general, heavier wire will improve the sound. For best performance, you
may want to consider special high-quality speaker cables. Your authorized
Rotel dealer can help in the selection of cables for your system.

Polarity and Phasing

The polarity - the positive/negative orientation of the connections - for every
speaker and amplifier connection must be consistent so all the speakers will
be in phase. If the polarity of one connection is reversed, bass output will
be very weak and stereo imaging degraded. All wire is marked so you can
identify the two conductors. There may be ribs or a stripe on the insulation
of one conductor. The wire may have clear insulation with different color
conductors (copper and silver). There may be polarity indications printed
on the insulation. Identify the positive and negative conductors and be
consistent with every speaker and amplifier connection.

Speaker Connection

Turn off all the components in the system before connecting the speakers.
The amplifier has color-coded binding post type speaker connectors on the
back panel. These connectors accept bare wire, connector lugs, or dual
banana type connectors. (Except in European Community countries where
their use is not permitted.)
Route the wire from the amplifier to the speakers. Give yourself enough slack
so you can move the components to allow access to the speaker connectors.
If you are using dual banana plugs, connect them to the wires and then
plug into the backs of the binding posts. The thumbscrews of the binding
posts should be screwed in all the way (clockwise).
\
. The speaker outputs are controlled by the A-B speaker
J
5
on the front panel or
11
]
and
on the remote control.

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