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.
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.
