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. Un-
screw (turn counterclockwise) the binding post thumbscrews.
Place the connector lug or wire around the binding post shaft.
Turn the thumbscrews clockwise to clamp the connector lug or
wire firmly in place.
Speaker Outputs 21 and 22
The RA-985BX has two sets of speaker outputs, labeled “A” and
B”. The Speaker Selector on the front panel controls which
set(s) of speakers are operating.
Note: Be sure there are no loose wire strands that could touch
adjacent wires or connectors.
If only one set of speakers will be played at any one time, the
speakers may have an impedance as low as 4 ohms. If both the A
and B sets of speakers will be operated at the same time the
speaker should have an impedance of 8 ohms or more. Speaker
impedance ratings are less than precise. In practice, very few
loudspeakers will present any problems for the RA-985BX. See
your authorized Rotel dealer if you have any questions.
Front Panel Controls
Speaker Wire Selection
Volume Control 10
Use insulated two-conductor stranded wire to connect the RA-
The Volume control increases or decreases the volume in both
channels at the same time. Turn it clockwise to increase the vol-
ume and counterclockwise to decrease the volume.
85BX 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 dimin-
ished bass response, particularly over longer distances. In gen-
eral, 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 appropri-
ate cables for your system.
Balance Control 11
The Balance Control alters the relative volume level of the two
channels. Turn the Balance Control to the right to make the right
channel louder. Turn it to the left to make the left channel louder.
Polarity and Phasing
Tone Defeat Switch
The polarity — the positive/negative orientation of the connec-
tions — for every speaker and amplifier connection must be con-
sistent 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 insu-
lation of one conductor. The wire may have clear insulation with
different color conductors (copper and silver). There may be po-
larity indications printed on the insulation. Identify the positive
and negative conductors and be consistent with every speaker
and amplifier connection.
When the Tone Defeat switch is set to “On” the Bass and Treble
tone controls can be used to adjust the bass and treble content of
the sound. When the Tone Defeat switch is set to “Off” the tone
controls are removed from the signal path. If you are not using the
tone controls leave the Tone Defeat switch in the “Off” position to
ensure the purest possible sound.
and Treble Control
When the Tone Defeat switch is set to “On” turning the tone con-
trols clockwise increases the bass or treble output. Turning the
controls counterclockwise decreases the bass or treble output.
The RA-985BX has two sets of color coded binding posts on the
back panel. These connectors accept bare wire, connector lugs,
or dual banana type connectors (except in the European Commu-
nity countries where their use is not permitted).
Route the wire from the RA-985BX to the speakers. Give yourself
enough slack so you can move the components 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 thumbscrews of
the binding posts should be screwed in all the way (clockwise).