CONTRACTOR PRECISION SERIES
Owner‘s Manual 13
2.10 Audio Cabling
Input
Inputs are electronically balanced. Whenever possible, using balanced audio signal feeds at the input of the power amplifier is
always preferred. Unbalanced connections should only be used if the cables are very short and no interfering signals are to be
expected in the vicinity of the power amplifier. In this case, bridging the screen (shielding) and the pin of the inverting input
inside of the connector is mandatory. Otherwise, a 6 dB drop in level could result. Please also see following illustration. Due to
their immunity against external interference sources, such as dimmers, mains connections, HF-control lines, etc., using
balanced cabling and connections is always preferable.
Output in DUAL Mode or PARALLEL Mode
See illustration right for connecting speakers in DUAL or PARALLEL mode.
Only connection of CH 1 and CH 2 is shown, the other channels have to be
connected identically.
The correct connection is also indicated at the amplifiers rear panel.
Output in BRIDGED Mode
See illustration right for connecting speakers in BRIDGED mode. Only connection
at CH 1/CH 2 is shown, the other channels have to be connected identically.
The correct connection is also indicated at the amplifiers rear panel.
Illustration 2.8: Balanced / unbalanced connection of input
CAUTION:
In BRIDGED mode operation, it is not allowable for the load connected to fall below the values
given in table 2.2 on page 9. Extremely high voltages can be present at the output. The con-
nected speaker systems must be able to handle such voltages. Make sure to completely read
and fully observe power rating specifications of the speaker systems to be used and to check
them against the output power capacity of the power amp.