ROTEL RB-06 - Manual (Page 7)

7 English
Speaker Connection
Speaker Selection
We recommend using loudspeakers with a
nominal impedance of 4 ohms or higher with
the RB-06. You should exercise some caution
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 imped-
ance of 8 ohms or higher. Speaker impedance
ratings are less than precise. In practice, very
few loudspeakers will present any problems for
the RB-06. See your authorized Rotel dealer if
you have any questions.
Speaker Wire Selection
Use insulated two-conductor stranded wire
to connect the RB-06 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 general, heavier wire will im-
prove 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 — the positive/negative orientation
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
identify 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.
Stereo Speaker Connection 9
The RB-06 has two 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).
Route the wire from the RB-06 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 thumbscrews
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
counterclockwise) 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.
Bridged Mono Operation
4
[See Figure 3 for bridged operation jumper
setting and connection illustration.]
The two channels of the RB-06 can be “bridged”.
In this configuration the single channel produces
a massive 180 watts! This feature allows you to
increase the overall power output of your system
by bridging the RB-06 and adding a second
bridged RB-06. Or the RB-06 is bridged to
drive a monophonic subwoofer. Note however
that when the RB-06 is bridged the speaker
connected to it must have an impedance of 8
ohms or more.
In order to use the RB-06 in bridged mode, three
“jumper” connectors inside the amplifier must be
moved from one set of pins to another. This task
should be done by a qualified technician. See
your authorized Rotel dealer. In addition the
RB-06 is connected to the other components in
a different way. When the RB-06 is setup for
bridged operation the Bridged Mono indicator
light 4 on the front panel will light.
Resetting Jumpers
Before opening the RB-06 cabinet to reset
the jumpers, the power cord must be un-
plugged from the wall. DO NOT OPEN THE
CABINET OF THE RB-06 BEFORE THE
POWER CORD HAS BEEN UNPLUGGED
FROM THE WALL. FAILURE TO DO SO WILL
EXPOSE YOU TO HAZARDOUS VOLTAG-
ES.
After the power cord has been unplugged,
remove the screws that hold the cabinet cover
in place and slide the cover off the amplifier.
Locate the three jumper pin blocks labeled
S 601, S 602 and S 603. The factory standard
(stereo) position of the jumpers is on pins 1
and 2 of each block. There is a * mark on the
circuit board next to this position. To convert the
RB-06 to bridged mono move all three jumpers
so they are on pins 2 and 3 of each jumper
pin block. Replace the cover of the cabinet. Do
not plug the RB-06 power cord back
into the wall outlet until the cabinet
cover has been replaced.
Input Connection
When using the RB-06 in bridged mono mode,
connect the cable from the preamplifier output
to the left input. No connection is made to the
right input.
Bridged Speaker Connection
When using the RB-06 in bridged mono mode,
the wire to the speakers is connected to the
positive terminals of the left and right chan-
nels. Connect the wire that goes to the positive
terminal of the speaker to the positive terminal
of the left channel of the RB-06. Connect the
wire that goes to the negative terminal of the
speaker to the positive terminal of the right
channel of the RB-06. No connections are made
to the negative terminals of the RB-06.