Carver pm125 Manuale Utente

of gain (see Figure 4B). For all versions of the amplifiers, the gain remains the same regardless of
whether the input is balanced or unbalanced.
Note: The polarity of the balanced inputs can be reversed by changing four jumpers on the Main
Board near the barrier strip inputs. Cross wire JP103 and JP104 to change the input polarity of CH1
and cross wire JP101 and JP102 to change CH2. 
CAUTION: To avoid the risk of electric shock, refer all internal adjustments to qualified service
p e r s o n n e l .

The input sensitivity of the amplifiers are set at the factory to 1.5V

R M S

for rated output. The input sensitivity

can be changed to 0.775V

R M S

by adding two jumpers on the Main Amplifier Board. See page 14 of this

o w n e r’s manual for more information.

For Normal Stereo or Dual Mono operation, use the red and black binding posts associated with each channel.
These are multi-way binding posts that can be used with standard single or double banana connectors, bare
wire (up to 8 gauge) or spade lugs.
Use  heavy-gauge  wire  for  speaker  connections.  The  greater  the  distance  between  the  amplifier  and  the
speakers, the larger the diameter the wire should be to minimize power losses across the wire and improve the
damping of the speaker. Wire thickness specifications, or gauges, get larger as the wire gets thinner; thus 14-
gauge wire is thicker than 18-gauge wire. Use the following chart as a guide:

Up to 8 ft.

18 gauge

Up to 12 ft.

16 gauge

Up to 20 ft.

14 gauge

Up to 30 ft.

12 gauge

Up to 50 ft.

10 gauge

This will insure that the resistance of the speaker wire is less than 2.5% of 4 ohms, resulting in a transmission
loss of less than 0.1dB. Class II (NEC) wiring can be used.

Loudspeakers must be connected with consistent polarity for correct phasing between them. Incorrect phasing
will do no physical harm, but frequency response will be affected. The key is to make sure that both speakers
connected to the speaker terminals are hooked up the same way. Connect (–) at the speaker outputs to (–) on
the back of the speaker, and (+) at the speaker outputs to (+) on the back of the speaker.

For dual-mono operation, turn the amplifier off and move the Stereo/Mono switch to the DUAL M O N O
position. Connect the input signal to CH2 input (CH1 input becomes disabled). Connect the speakers to the
Speaker Outputs on the amplifier in the same way that you would for normal stereo operation. Both speaker
outputs will carry the signal that is connected to the CH2 input.

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