Bridged Mono
When in Bridged Mono setting connect the input signal to CH2 input (CH1 input becomes disabled). Connect
the speaker(s) to the two (+) speaker terminals. The CH2 (+) terminal is the hot (+)(non-inverting) side, and the
CH1 (+) terminal is the low (–)(inverting) side. When connected in this way, each channel “sees” one-half the
impedance of the speaker that is connected between them. If an 8 ohm speaker is used, each channel will see a 4
ohm load. Therefore it is not recommended that any load lower than 8 ohms be connected in this mode of
operation. Use Parallel Mono operation for lower impedances.
N o t e : Be sure to set both of the input level controls to the exact same setting for equal power distribution per channel.
CAUTION: In bridged mono operation, the output connections are actually a balanced output configuration. T h i s
means that both output terminals have voltage present (neither one may be grounded).
Parallel Mono
To configure the amplifier for parallel-mono operation, change the output configuration switch located on the
back panel of the amplifier. Connect input source to CH2 (CH1 gain control is now disabled). Connect speaker
to either CH1 or CH2 or both.
N o t e : To daisy chain the input audio signal to additional amps, a balanced signal Y-adaptor connected to the channel
input is recommended.
7 0 V Distribution Systems–PX850
The PX850 can be used to drive 70-volt distribution systems using Carver Professional’s output distribution
transformer (available separately from your Carver Professional dealer). Order X0450. Connect one transformer
to the output of each amplifier channel to deliver 425 watts (PX850) to the 70-volt system, depending on the
impedance of the total system. As with all 70-volt systems, transformers are also required at each loudspeaker.
The XO-450A transformer includes a tap for 100-volt systems as well.
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7 0 V Distribution Systems–PX1450
The PX1450 has sufficient output voltage capability in stereo mode to drive 70-volt distribution
systems without using a step-up transformer at the amplifier. In this configuration, the PX1450 delivers
up to 375 watts per channel to the 70-volt system, depending on the impedance of the total system. A s
with all 70-volt systems, transformers are still required at each loudspeaker. The PX1450 can deliver
375 watts per channel into an 8 ohm impedance (54V line voltage). The price for going direct is having
to calculate the new transformer tap values at the new line voltage. Since watts are proportional to the
square of the voltage, compute the correction factor by taking the ratio of the square of the line voltages.
Then multiply each tap value by this correction factor. For example, choose a transformer that has taps
at 10W, 5W and 2.5W when used in a 70.7 volt distribution. Its new tap values when used with a
PX1450 are computed as follows:
1. Complete correction factor K:
K = 54V
2
/ 7 0 . 7 V
2
K = .583
2. Apply to tap value:
Marked tap value X K = new tap value
1 0 W X .583 = 5.83W
5 W X .583 = 2.92W
2 . 5 W X .583 = 1.46W
When used in a 70.7 volt distribution system, this transformers new tap values are 5.8W, 2.9W, and 1.5W. Note
that the 3dB power relationship between each tap still holds true. Similarly, maximum amplifier loading occurs
when the sum of the NEW tap values equals the amplifier’s output power (375W).
Signal Smart Standby Circ u i t
Allows amplifier to remain “on”, but when signal is not present for 3 minutes, amplifier goes into standby mode.
Current draw is reduced, fan shuts down, amp remains in standby until signal returns. Within 50 milliseconds of a
signal present, amplifier returns to full power. Signal level for shut down and power up is adjustable by Signal
Smart Threshold Control located on rear panel. Unit is shipped with Threshold Control set at “bypass”. (See
Diagram G for setting levels). The Bypass setting defeats the Signal Smart Standby Circuit and the amplifier
remains on at all times. When the indicator is in the -50dB to -20dB range, it will control the amount of signal
required to return the amplifier to full power from standby (-50dB requiring a very weak source signal, -20dB
requiring a very strong source signal).
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Figure G
