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Audio controls, Protection circuitry, Troubleshooting – ROTEL RA-04 User Manual

Page 8

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8

Audio Controls

Volume Control

Turn the controls clockwise to increase the
volume, or counterclockwise to decrease the
volume.

Balance Control

The Balance Control adjusts the left-to-right
balance of the sound output. Normally the
control should be left in the center position.
In some situations, typically when the main
listening position is not ideally centered be-
tween the speakers, it may be necessary to
adjust the control to achieve proper left-to-right
balance. Turning the control counter-clockwise
shifts the sound balance to the left. Turning
the control clockwise shifts the sound balance
to the right.

Tone On/Off Switch

When the Tone Switch is in the Off position the
Bass and Treble Control (Tone Control) circuits
are bypassed to ensure the purest possible
sound. Leave the Tone Switch in the Off posi-
tion unless you want to use the Tone Controls.
Turn the Tone Switch to the On position if you
want to adjust the Tone Controls.

Bass and Treble Controls

When the Tone Switch is in the On position,
turning the Bass and Treble Controls adjusts the
tone balance of the sound. Turn the Controls
clockwise to increase the bass or treble output.
Turn the Controls counterclockwise to decrease
the bass or treble output.

A properly set up high-performance audio
system produces the most natural sound with
little or no adjustment of the tone controls. Use
these controls sparingly. Be particularly careful
when turning the controls up (clockwise). This
increases the power output in the bass or treble
range, increasing the load on the amplifier
and speakers.

Function Control

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The Function control selects the input signal
source. The signal selected by the Function
control is the one you hear, as long as the
Monitor control is set to the Source postion.
(See the following section.) The signal selected
by the Function control also goes to Preamp
Outputs and the Tape Outputs. Turn the front
panel Listening Selector to the source you
want to listen to.

Monitor Control

When the Monitor Control is set to the Source
position, the signal you hear, and which goes
to the Preamp Outputs, is selected by the
Function Control. To listen to the signal from a
recorder connected to the Tape Inputs, set the
Monitor Control to the Tape position. When
the Monitor Control is in the Tape position,
the signal from the Tape Input also goes to the
Preamp Outputs.

The signal that goes to the Tape Output is always
selected by the Function Control. When you
are recording with a unit that has monitoring
capabilities, you can listen to the sound just
recorded by setting the Monitor Control to the
Tape position.

Protection Circuitry

The RA-04 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 play-
ing and the LED indicator on the front panel
will light up.

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 indicator LED
should go out.

In most cases, the protection circuitry activates
because of a fault condition such as shorted
speaker wires, or inadequate ventilation lead-
ing to an overheating condition. In very rare
cases, highly reactive or extremely low imped-
ance 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.

Troubleshooting

Most difficulties in audio systems are the result
of incorrect connections, or improper control
settings. If you encounter problems, isolate the
area of the difficulty, check the control settings,
determine the cause of the fault and make the
necessary changes. If you are unable to get
sound from the RA-04 refer to the suggestions
for the following conditions:

Power Indicator Is Not Lit

The Power Indicator should be lit whenever the
RA-04 is plugged into the wall power outlet
and the Power Switch is pushed in. If it does
not light, test the power outlet with another
electrical device, such as a lamp. Be sure the
power outlet being used is not controlled by
a switch that has been turned off.

Fuse Replacement

If another electrical device works when plugged
into the power outlet, but the Power Indicator
of the RA-04 does not light when plugged into
the same outlet and the Power Switch is pushed
in, it indicates that the internal power fuse may
have blown. If you believe this has happened,
contact your authorized Rotel dealer to get the
fuse replaced.

No Sound

Check the signal source to see if it is function-
ing properly. Make sure the cables from the
signal source to the RA-04 inputs are connected
properly. Be sure the Listening Selector is set
to the proper input. Check the wiring between
the RA-04 and the speakers.

RA-04 Stereo Integrated Amplifier