Input Signal Connection; Db25 Connector Input; Speaker Connection; Speaker Selection - Rotel RMB-1075 Bedienungsanleitung

If this happens, turn the amplifier off, let it cool
down for several minutes, and attempt to iden-
tify and correct the problem. When you turn
the amplifier back on, the protection circuit
will automatically reset and the LED indica-
tor 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 im-
pedance speaker loads could cause the pro-
tection circuit to engage.
If the protection circuitry triggers repeatedly
and you are unable to isolate and correct the
faulty condition, contact your Rotel audio
retailer for assistance in troubleshooting.

Input Signal Connection

[See Figure 2 for wiring illustration.]
The RMB-1075 has conventional RCA type in-
put connectors, the type found on nearly all
audio equipment.
Note: Do not connect inputs to both the
RCA and DB25 inputs. (See the following
section.) Use one or the other.
Note: To prevent loud noises that neither
you nor your speakers will appreciate,
make sure the amplifier is turned off when
you make any signal connections.
Use high quality audio interconnect cables.
Connect the various outputs of your pream-
plifier or signal processor to the correspond-
ing inputs of the RMB-1075. Check these con-
nections carefully to be sure there are no in-
correct connections.

DB25 Connector Input

The RMB-1075 is also equiped with a DB25
type input. This input is typically only used in
professionally-installed custom systems. The
DB25 input duplicates the function of the five
RCA inputs. For information regarding how
to use this input, contact your nearest autho-
rized Rotel service center.
7

Speaker Connection

Speaker Selection

We recommend using loudspeakers with a
nominal impedance of 4 ohms or higher with
the RMB-1075. You should exercise some cau-
tion in driving multiple pairs of speakers in
parallel configuration, because the effective
impedance the amplifier sees is cut in half.
For example, when driving two pair of 8 ohm
speakers, the amplifier sees a 4 ohm load.
When driving multiple speakers in parallel,
it is recommended that you select speakers
with a nominal impedance of 8 ohms or higher.
Speaker impedance ratings are less than
precise. In practice, very few loudspeakers will
present any problems for the RMB-1075. See
your authorized Rotel dealer if you have any
questions.

Speaker Wire Selection

Use insulated two-conductor stranded wire to
connect the RMB-1075 to the speakers. The
size and quality of the wire can have an au-
dible 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 spe-
cial high-quality speaker cables. Your autho-
rized Rotel dealer can help in the selection
of appropriate cables for your system.

Polarity and Phasing

The polarity — the positive/negative orien-
tation of the connections — for every speaker
and amplifier connection must be consistent
so all the speakers will be in phase. If the po-
larity of one connection is mistakenly reversed,
bass output will be very weak and stereo im-
aging 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 insula-
tion 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
The RMB-1075 has five pairs of color coded
binding posts on the back panel. These con-
nectors accept bare wire, connector lugs, or
dual banana type connectors (except in the
European Community countries where their
use is not permitted).
The negative connectors for all the channels
are black. The positive connectors for the right
front and surround speakers are red. The posi-
tive connectors for the left front and surround
speakers are blue. The positive connector for
the center speaker is green.
Route the wire from the RMB-1075 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 dual banana plugs, connect
them to the wires and then plug into the backs
of the binding posts. The hexagonal thumb-
screws of the binding posts 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 binding posts, 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 coun-
terclockwise) the binding post hexagonal
thumbscrews. Place the connector lug or wire
around the binding post shaft. Turn the hex-
agonal thumbscrews clockwise to clamp the
connector lug or wire firmly in place.
Note: Be sure there are no loose wire
strands that could touch adjacent wires or
connectors.
English