Rotel RB-951MkII owner manual Speakers

Clipping Indicators

Two front panel LEDs (one for each channel) flash to indicate when the amplifier is “clip- ping” or being asked to deliver more output current than it is capable of delivering. Clip- ping will cause distortion levels to increase.

Occasional brief clipping on the loudest mu- sical passages is acceptable. However, sus- tained or frequent clipping is one of the most common causes of speaker damage and should be avoided.

Should this occur, either reduce the overall gain of the system by turning down the master volume control on your preamp. Alternatively, you may wish to permanently reduce the gain of the amplifier using the front panel level controls (see previous section).

Signal Output Link

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 amplifier to drive a second set of speakers. Any INPUT SIGNAL is also avail- able at these LINK outputs.

Speakers

The RB-951MkIIhas two pair of speaker con- nectors, one pair for each channel. These can be used to connect two loudspeakers in Ste- reo mode, or to connect one loudspeaker in Bridged Mono mode.

Speaker Selection

The nominal impedance of the loudspeaker(s) connected to the RB-951MkIIin the various operating modes should be:

•Stereo mode: minimum 4 ohms

•Bridged Mono mode: minimum 8 ohms

•Parallel Mono mode: minimum 2 ohms

When driving multiple pairs of speakers con- nected in parallel, the effective impedance the amplifier sees is cut in half. For example, when driving two pair of 8 ohm speakers, the am- plifier sees a 4 ohm load. When driving mul- tiple speakers in parallel, select speakers with a nominal impedance of 8 ohms or higher.

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Speaker Wire Selection

Use insulated two-conductor stranded wire to connect the RB-951MkIIto 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 re- sult 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 orienta- tion of the connections – for every speaker and amplifier 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 wire is marked so you can iden- tify the two conductors. There may be ribs or a stripe on the insulation of one conductor. The wire may have clear insulation with dif- ferent color conductors (copper and silver). There may be polarity indications printed on the insulation. Identify the positive and nega- tive conductors and be consistent with every speaker and amplifier connection.

Speaker Connections

See Figures 2 & 3

The RB-951MkIIhas one pair of color coded connections per channel. Labels above the connectors show the proper connections for Stereo mode. Labels below show the proper connections for Bridged Mono mode.

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 RB-951MkIIto the speakers. Give yourself enough slack so you can move the components enough to allow access to the speaker connectors.

English

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 insu- lation from the end of each conductor. Be careful not to cut into the wire strands. Unscrew (turn counterclockwise) the speaker connector col- lar. 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 firmly in place.

NOTE: Be sure there are no loose wire strands that could touch adjacent wires or connec- tors.

In Stereo mode: Connect the left speaker to the pair of speaker connectors labeled CH

1.Connect the right speaker to the speaker connectors labeled CH 2. Follow the labels printed above the connectors and make sure the BRIDGE MODE switch is set to the NOR- MAL STEREO position. (See Figure 2)

In Bridged Mono mode: Connect the posi- tive terminal of the speaker to the speaker con- nector labeled BRIDGE +. Connect the nega- tive terminal of the speaker to the speaker con- nector labeled BRIDGE –. Follow the labels printed below the connectors and make sure the BRIDGE switch is set to the BRIDGE MONO position. (See Figure 3)

In Parallel Mono mode: Connect the speak- ers in the same fashion as in the Stereo mode. You can use the connectors for either chan- nel or both – the same output signal is present at both pair of connectors. (See Figure 2)