Linking The Inputs; Input Level Controls; Signal Output Link; Speakers - Rotel RMB-1506 Owner's Manual

English

Linking the Inputs

5
You can link the inputs for groups "B" and/ or "C" to the "A" inputs
by placing the input slide switch to the right of each pair of RCA inputs
in the LINK position. When linked, no input connection is required for
that group. The input signal from the "A" group is sent to the linked
pair of channels, allowing you to use four or six amplifi er channels
with the same stereo input signals.

Input Level Controls

3
Three controls on the front panel, one for each pair of channels,
provide input level adjustments. These allow you to adjust the gain
of the amplifi er to match other components in the system. The A level
control changes the gain of the "A" channels; the B level control
changes the "B" channels; the C level control changes the "C"
channels.
To adjust these controls, use a small, fl atblade screwdriver. Turn the
control clockwise to increase gain. Turn counterclockwise to reduce
gain.

Signal Output Link

6
This pair of RCA connections can be used to pass the unprocessed
input signals to another audio component, for example to "daisy-
chain" an additional amplifi er to drive a second set of speakers. The
input signals connected to the "A" channels is also available at these
LINK outputs.
Note: These input signals from the "A" channels can also be linked
to the "B" and/or "C" inputs by playing the INPUT SELECT switch
associated with that pair of channels in the LINK position.

Speakers

The RMB-1506 has three groups of speaker connectors, one for each
pair of amplifi er channels.

Speaker Selection

The nominal impedance of the loudspeaker(s) connected to the
RMB-1506 should be a minimum of 4 ohms. When driving multiple
pairs of speakers connected in parallel, the effective impedance the
amplifi er sees is cut in half. For example, when driving two pair of 8
ohm speakers, the amplifi er sees a 4 ohm load. When driving multiple
speakers in parallel, select speakers with a nominal impedanceof 8
ohms or higher.

Speaker Wire Selection

Use insulated two-conductor stranded wire to connect the RMB-1506
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 appropriate cables for your system.

Polarity and Phasing

The polarity or positive/negative orientation of the connections for
every speaker and amplifi er connection must be consistent so all
the speakers will be in phase. If the polarity of one connection is
mistakenly reversed, bass output will be very weak and stereo imaging
degraded. All speaker 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 thepositive and negative conductors
and be consistent with every speaker and amplifi er connection.

Speaker Connections

9
See Figure 2
The RMB-1506 has two pair of color coded connections for each
group of amplifi er channels, one for the left speaker, the other for
the right speaker. Labels above the connectors show the proper
connections for connecting speakers. These speaker connectors accept
bare wire, connector lugs, or "banana" type connectors (except in the
European Community countries where their use is not permitted).
Route the wires from the RMB-1506 to the speakers. Give yourself
enough slack so you can move the components enough to allow
access to the speaker connectors.
If you are using banana plugs, connect them to the wires and then
plug into the backs of the speaker connectors. The collars of the
speaker connectors should be screwed in all the way (clockwise).
If you are using terminal lugs, connect them to the wires. If you are
attaching bare wires directly to the speaker connectors, separate the
wire conductors and strip back the insulation from the end of each
conductor. Be careful not to cut into the wire strands. Unscrew (turn
counterclockwise) the speaker connector collar. Place the connector lug
around the shaft, or insert the bundled wire into the hole in the shaft.
Turn the collars clockwise to clamp the connector lug or wire fi rmly in
place.
Note: Be sure there are no loose wire strands that could touch
adjacent wires or connectors.
For each group of channels, connect the left speaker to the pair of
speaker connectors labeled LEFT. Connect the right speaker to the
speaker connectors labeled RIGHT. Follow the labels printed above
the connectors, Make sure that the positive terminal of the speaker
is connected to the + terminal on the amplifi er. Make sure that the
negative terminal of the speaker is connected to the – terminal of the
amplifi er.
9