Parasound
®
ZoneMaster
™
250 Owner’s Manual
Page 9
Audio Output Connections
Loop Out Jacks
These jacks enable the audio source to pass along or “daisy chain” to additional amplifier. Audio from the
Speaker Level Input connector is also converted to line level and routed to the Loop Out jacks.
Mono Out Jack (Full range)
This is a full range output that combines the Left and Right channel inputs into a summed L + R mono
signal. This could be useful for connecting a powered subwoofer that has its own built in crossover. It
could also be used for connecting an additional amplifier in mono applications.
Sub Out Jack (80
Hz Low Pass)
This is a low pass output that combines the left and right inputs into a summed L + R mono signal. This
could be useful for connecting a passive in-wall subwoofer. The crossover is 80
Hz with an 18
dB per
octave slope. This jack is always active regardless of the setting of the Bridged Output switch. If you are
using this output with a powered sub then you must turn off the crossover built into the sub.
Connecting Speaker Wires
Detach the green speaker output connecting blocks by pulling them away from the ZoneMaster 250 rear
panel. This makes attaching speaker wires far more convenient. Connect the connecting block’s + and –
terminals to the corresp and – speaker wires. Never combine the – of two channels together.
The
ends of the wires should be twisted tightly and/or lightly tinned with solder to prevent stray wire strands from
short circuiting the amplifier.
The minimum speaker load impedance is 2 ohms in Stereo Mode or 4 ohms when Bridged Mode is
selected. When driving low impedance loads ensure that the ZoneMaster 250 has adequate
ventilation and is not installed in a cabinet that is totally enclosed.
Speaker A and B Outputs
The ZoneMaster 250 is equipped with connections for two speakers on each channel (labeled A and B).
This unique feature gives system designers greater flexibility and can usually avoid the added expense,
complexity, heat and power consumption of additional amplifiers. The ability of the ZoneMaster 250 to drive
two pair of speakers is credited to Parasound’s 2 ohm stable high current design.
Typical applications for using both Speaker A and B outputs might include a large living room with four
ceiling speakers. Another use for the B speakers could be in a subzone like a bathroom or hallway adjacent
to the room where the A speakers are installed. This adjacent subzone might also use a passive in-wall
volume control to adjust its listening level separately.
Total Speaker Impedance (A + B):
When you select the Stereo Mode the R and L channels are each
capable of driving speaker loads as low as 2 ohms. An example of a 2 ohm load is one 4 ohm speaker
connected to a channel’s speaker output A while another 4 ohm speaker is connected to the same
channel’s speaker output B. When driving 2 ohm loads ensure the amplifier has adequate ventilation.
When you select the Bridged Mode the L and R channels are used together as one channel with higher
power output. A channel pair in bridged mode is capable of driving a 4 ohm minimum load. An example of
a 4 ohm load is a single 8 ohm speaker connected to speaker output A and another 8 ohm speaker is
connected to the speaker output B. See page 10 for more information on Bridged Mode.
Bridged Mode Connections:
When you select the Bridged Mode the L and R channels are used
together as one channel with higher power output. A channel pair, or zone, in Bridged Mode is capable of
driving a 4 ohm load. When you have selected Bridged Mode only use the
L+ and R –
terminals. Only the
R channel Input jack and Level control are used. See page 10 and 11 for more details.
CONNECTION WARNING:
Never combine the Speaker L & R channel negative (
−
) outputs together.
Some speaker selectors combine the negative connections and are not compatible with the ZoneMaster
250. Combining the negatives of any two channels would cause the amplifier to engage its protection circuit
and could seriously damage the amplifier. L and R channel speakers cannot be wired where they share a
single negative (
−) wire.
