Parasound
®
ZoneMaster
™
1250 Owner’s Manual
Page 8
Audio Output Connections
Bus 1 and 2 Loop Out Jacks
These jacks enable the audio source connected to the Bus 1 and 2 Input jacks to pass along or “daisy
chain” to an additional amplifier. The volume level and signal voltage at the Bus 1 and 2 Loop Out jacks is
the same as the volume level and signal voltage of the sources that are connected to their corresponding
Bus 1 and 2 Input jacks. Audio from the Speaker Level Input connector is converted to line level and
simultaneously routed to the Bus 2 RCA Loop Out jacks to drive additional amplifiers.
Connecting Speaker Wires
Detach the green speaker output connecting blocks by pulling them away from the ZoneMaster 1250 rear
panel. This makes attaching speaker wires far more convenient. Removing them might require a bit of
effort because the connecting blocks are seated very securely. Connect the connecting block’s + and –
terminals to the corresp and – speaker wires.
Note:
The minimum speaker load impedance is 2 ohms in Stereo Mode or 4 ohms when
Bridge Mode is selected. When driving low impedance loads ensure that the ZoneMaster
1250 has adequate ventilation and is not installed in a cabinet that is totally enclosed.
Note:
The speaker connector blocks accept bare wires as large as AWG12. 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.
Speaker A and B Outputs
The ZoneMaster 1250 is equipped with connections for two speakers on each channel (labelled 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 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.
Speaker A and B Impedance:
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, or zone, 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 the L+ and R
−
output of Speaker A and
another 8 ohm speaker is connected to the L+ and R
−
output of Speaker B. See page 9 for more
information on Bridged Mode.
CONNECTION WARNING:
Never combine the Speaker L & R channel negative (
−
) outputs together.
Combining the negatives of any two channels could seriously damage the amplifier. Speakers cannot be
wired where the L and R channel speakers share a single negative (
−
) wire. Some speaker selectors
combine the negative connections and are not compatible with the ZoneMaster 1250.
