8
The jack labeled OUT is for connecting another 3.5mm mono plug/cable
to provide a 12 volt trigger signal to other components. The 12 volt output
signal is available whenever a +12 volt trigger signal is applied to the IN
connector.
NOTE: The maximum current for the trigger out is 10mA.
Protection Indicator
1
The RKB amplifiers feature thermal and over-current protection circuits that
protect against potential damage in the event of extreme or faulty operating
conditions.
Most likely, you will never see this protection circuitry in action. However,
should a faulty condition arise, the amplifier will shut down and the Power
Indicator on the front panel will be blinking.
If this happens, turn the amplifier off, let it cool down for several minutes,
and attempt to identify and correct the problem. When you turn the amplifier
back on, the protection circuit will automatically reset and the Power Indicator
should light up, indicating that the amplifier is operating normal.
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.
Signal Connections 234
See Figure 2
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.
The RKB amplifier provides standard RCA type input connections as found
on nearly all audio equipment.
In addition to the four groups of stereo inputs labeled INPUT A to INPUT D,
there is also a pair of PREAMP OUTPUT connections for passing the signal
connected to INPUT A to another audio component.
RCA Inputs
4
There are two RCA inputs for each of the four pairs of amplifier channels.
These RCA inputs accept audio signals from preamplifiers or surround sound
processors. Select high quality audio interconnect cables for best performance.
For each pair of amplifier channels, connect the left channel output of your
preamp to the LEFT INPUT on the amplifier. Connect the right channel of
your preamp to the RIGHT INPUT. Make sure that the input switch to the
right of the RCA inputs is in the STEREO position.
RKB Series Eight Channel Power Amplifiers
Linking the Inputs
4
You can link the analog and digital inputs to other channels by moving the
LINK/STEREO switch located next to the RCA inputs for Channel B, C and D
to the LINK position. When this switch is set to LINK the analog and digital
source of the preceding channel will be used for that channel. No source
input is required for a channel with LINK enabled. For example when channel
C is set to LINK the digital or analog source from channel B will be used.
NOTE: Both the analog and digital input source of INPUT A can be
linked to INPUTS B, C and D.
Mono Switch
4
For the channel INPUT A, when the input switch is moved to the MONO
position, the left and right RCA inputs are combined and provided to both
speakers as a mono signal. Channels linked to INPUT A will also be MONO
if the switch is moved to the MONO position.
Input Level Controls
2
Four controls on the front panel, one for each channel, provide input level
adjustments. These allow you to adjust the gain of the amplifier to match
source components attached to the amplifier. The INPUT A level control
changes the gain of the INPUT A channel; the INPUT B level control changes
the INPUT B channel and so on. The controls are not labeled on the front,
but when viewed from the front they are from left to right Input D,C,B,A,
with input A on the farthest right. To adjust these controls, use a small,
flat blade screwdriver. Turn the control clockwise to increase gain. Turn
counterclockwise to reduce gain.
Preamp Output
3
This pair of RCA connections can be used to pass unprocessed input signals to
another audio component, for example to "daisy-chain" to another amplifier
to drive additional speakers. The input signals connected to the INPUT A
connectors is available on the Preamp Output connectors. This is typically
used when the amplifier is part of a multi-room system.
NOTE: It is recommended to Daisy Chain a maximum of 8 RKB
amplifiers.
NOTE: The MONO switch does not affect the Preamp Output.
Optical Inputs
4
For RKB-D850 and RKB-D8100 Only
There is a digital input labeled OPTICAL for each channel. Connect the
OPTICAL PCM outputs of your source component into these sockets. The
digital signals will be decoded and played by the RKB-D850 or RKB-D8100.
The RKB is capable of decoding PCM signals up to 24 bit, 192kHz.
NOTE: The OPTICAL input will automatically be selected whenever a
digital signal is detected. Some source devices will continue to send a
signal even when no audio is being transmitted. An example is some
CD players will continue to send a signal even if the CD is paused
or stopped. In some cases it may be required to power off the digital
source device or even disconnect the Optical cable to switch back to
the Analog RCA input.