The Rb-951 Mkii; Input Sensitivity (S605 And S606); Selecting Parallel Mono Mode (S602 And P1/P3); Troubleshooting - Rotel RB-951 MkII Manuel D'utilisation

RB-951 Stereo Power Amplifier
MkII
Input Sensitivity
(S605 and S606)
Jumper blocks S605 and S606 are used to
set the input sensitivity of the amplifier.
For high sensitivity (0.775v input for
rated power): place the jumpers across pins
1 and 2 on jumper blocks S605 and S606.
For low sensitivity (1.5v input for rated
power): place the jumpers across pins 2 and
3 on jumper blocks S605 and S606.
Selecting Parallel Mono Mode
(S602 and P1/P3)
As described earlier in this manual, the two
most common operating configurations for the
RB-951 (Stereo mode and Bridged Mono
MkII
mode) are selectable with a back panel switch
and require no internal changes.
The third configuration, Parallel Mono mode,
allows both channels of the amplifier to be com-
bined in parallel. This mode is useful for driv-
ing a low impedance speaker load such as
driving multiple speakers in a custom instal-
lation.
This Parallel Mono mode can be selected only
by setting internal jumpers (jumper block S602)
and changing a buss wire connection (con-
nectors P1 and P2).
: it is essential that Parallel Mono mode
NOTE
not be engaged at the same time as Stereo
mode. This will blow the internal rail fuses.
Make sure that you follow all of the instruc-
tions below carefully.
To convert to Parallel Mono mode:
1. Place the jumper across pins 1 and 2 on
jumper block S602.
2. Locate the buss wire linking the P2 connector
to the P3 connector. Remove the wire from
P3 and move it to the adjacent P1 connector.
For Parallel Mono mode, the buss wire must
link P2 to P1.
To return to normal configuration (Ste-
reo or Bridged Mono modes):
1. Place the jumper across pins 2 and 3 on
jumper block S602.
2. Locate the buss wire linking the P2 connector
to the P1 connector. Remove the wire from
P1 and move it to the adjacent P3 connector.
For normal mode, the buss wire must link
P2 to P3.

Troubleshooting

Most difficulties in audio systems are the re-
sult of poor or wrong connections, or improper
control settings. If you encounter problems,
isolate the area of the difficulty, check the control
settings, determine the cause of the fault and
make the necessary changes. If you are un-
able to get sound from the RB-951
to the suggestions for the following conditions:
Front Panel Power Indicator Is
Not Lit
No main power to the RB-951
power connections at the amplifier and the
AC outlet. Check the front panel power switch.
Make sure that it is set to the ON position. If
using signal sensing auto power-on, make sure
that a signal is present at the inputs. If using
12V trigger power-on, make sure that a trig-
ger signal is present at rear panel screw ter-
minals.

No Sound

If the amp is getting AC power, but is producing
no sound, check the PROTECTION INDICA-
TORS on the front panel. If lit, see below. If
not, check all of your connections and con-
trol settings on associated components. Make
sure that your input connections and speaker
connections match your selected stereo/mono
configuration.

Protection Indicator Is Lit

The front panel PROTECTION INDICATORS
light when the RB-951 protection circuits
MkII
have shut off the amplifier. Typically, this oc-
curs only when the ventilation openings are
blocked, when there is faulty speaker wiring,
or after a period of extreme use. Turn off the
system and wait for the amp to cool. Then push
the front panel power switch in and out to re-
set the protection devices. If the problem is not
corrected or reoccurs, there is a problem with
the system or the amplifier itself.
12

Specifications

Continuous Power Output Stereo Mode
(20-20 kHz, < 0.03% THD)
50 watts/ch into 8 ohms
Continuous Power Output Bridged Mono
Mode (20-20 kHz, < 0.1% THD)
150 watts/ch into 8 ohms
Total Harmonic Distortion
(20Hz-20kHz, 8 ohms)
, refer
MkII
< 0.03%
Intermodulation Distortion
(60 Hz : 7 kHz, 4:1)
< 0.03%
Frequency Response (±1 dB)
15Hz-100kHz
. Check AC
MkII
Damping Factor (20-20,000 Hz, 8 ohms)
280
Speaker Impedance (combined load)
Stereo mode: 4 ohms minimum
Bridged Mono mode: 8 ohms minimum
Parallel Mono mode: 2 ohms minimum
Signal to Noise Ratio (IHF A network)
116 dB
Input Impedance
32 k Ohms
Input Sensitivity
1.5 volt (low setting)
0.775 volt (high setting)
Auto Turn On Threshold Level (if activated)
10 mV input signal
Auto Turn Off Delay Time (if activated)
5 minutes with no signal
Power Requirements
USA: 115 Volts, 60 Hz
Europe: 230 Volts, 50 Hz
Power Consumption
200 Watts
Dimensions (W x H x D)
440 x 92 x 334 mm
17 x 3
3/8
Weight (net)
6.8 kg, 15 lb.
All specifications are accurate at the time of printing.
Rotel reserves the right to make improvements
without notice.
x 13 in
5/8 1/4