Parasound NewClassic Model 2250 - Manual (Page 8)

REAR PANEL CONNECTIONS AND CONTROLS continued
Correct Speaker Polarity is Important
As you connect the speaker wires, you can see that the insulation on one of the two wires in
each pair has either printing or a raised ridge. The marking lets you know which wire you con-
nected to the positive speaker terminal at its other end.
Make sure the + wire you attach to each Model 2250 + speaker terminal is attached to the +
terminal of the speaker for that channel.
Bridging Switch: Stereo - Mono
The Model 2250 power should always be turned off before moving this switch.
For normal operation the Bridging switch must be set to Stereo.
For bridged mono operation, set it to Mono.
Note: Stereo sound will be faint and very distorted if you accidentally leave the Bridging switch
in its Mono position.
Mono Operation
We recommend an 8 ohm minimum speaker load for
bridged mono operation. For mono the Model 2250
“bridges” the R channel to amplify only the positive half
of the audio signal and the L channel to amplify only the
negative half of the audio signal. In effect, each channel
“sees” only half of the speaker’s rated impedance, so that an 8 ohm speaker in bridged mono
is only a 4 ohm load and a 4 ohm speaker in mono is only a 2 ohm load. This is why the mono
power output is much higher than the sum of the L and R channel outputs for stereo operation.
Mono Input and Speaker Connections
1. Turn the unit off and remove the AC cord.
2. Connect the single cable from the preamp or controller to the R channel Input jack.
3. Set the Bridging switch to its Mono position.
4. Connect the positive lead of the speaker wire to the red R + channel speaker pair A terminal.
5. Connect the negative lead of the speaker wire to the red L + channel speaker pair A terminal.
6. Do not connect anything to either the L - or R - speaker terminals.
7. If you have a second mono speaker repeat steps 4 - 6 with the speaker pair B terminals
8. Reconnect the AC cord.
Note: The Model 2250 creates more heat when it drives a bridged mono speaker or multiple
speaker pairs. Lower impedance speakers will make it run even hotter. Heat greatly reduces
the life of the amplifier and nearby components. Please heed the instructions for setting the
Load Impedance switch to avoid overheating.
Load Impedance Switch
6
WARNING: To Prevent Fire Or Shock Hazard,
Do Not Expose This Unit To Rain Or Moisture.
AC 115V/60Hz
AC 230V/50Hz
Speaker Pair A
L R
Mono
Manual Audio Sens
Max Min
12V Trigger Ground
Lift Norm
Mono Stereo
4-8
Ohms
2-3
Ohms
230V
50Hz
115V
60Hz
20Hz 40Hz Flat
Audio
Auto Turn On Loop Level
Bridging
In
12V
In Loop
R
Mono
+
+
AC 115V/60Hz
AC 230V/50Hz
Power Consumption: 300W
AC
Voltage
Load
Impedance
275 Two Channel Amplifier
Parasound Products, Inc.
San Francisco, CA U S A
CAUTION: To Prevent Electric Shock, Do Not Remove Cover. No
User-Serviceable Parts Inside. Refer Servicing To Qualified Service Personnel.
L
High Pass Filter
Speaker Pair B
L R
Mono
Manual Audio Sens
Max Min
12V Trigger
Audio
Auto Turn On
12V
Ground
Lift Norm
In Loop
CAUTION
To Prevent Electric Shock, Do Not
Remove Cover. No User-Serviceable
Parts Inside. Refer Servicing To
Qualified Service Personnel.
WARNING
To Prevent Fire Or
Shock Hazard, Do
Not Expose This Unit
To Rain Or Moisture.
2250 Two Channel Amplifier
Parasound Products, Inc.
San Francisco, CA U S A
Mono Stereo 20Hz 40Hz Flat
Bridging High Pass Filter
Level Input Loop
R
Mono
L
R
L
Mono
THX
Ref
THX
Ref
Speaker Pair A
L R
Mono
Speaker Pair B
L R
Mono
Power Consumption: 800W
THX and Ultra2 are trademarks of THX Ltd.
which may be registered in some jurisdictions.
All right reserved.
4-8
Ohms
2-3
Ohms
230V
50Hz
115V
60Hz
AC
Voltage
Load
Impedance
AC 115V/60Hz
AC 230V/50Hz
AC 115V/60Hz
AC 230V/50Hz