Hafler P7000 - Manual (Page 6)

I
N S T A L L A T I O N
LOCATION
The P7000 uses forced-air fan cooling to remove the heat produced in normal operation. Although this makes
the amplifier less sensitive to ventilation than if it were passively cooled, fresh air flow at the mounting location
must still be considered. The fan pulls in fresh air through the side vents and the heated air is forced out through
the front panel. Another consideration when choosing the location for a fan cooled amplifier is its proximity
to the listening position. In some situations the sound of the fan operation can be distracting.
The power transformer can generate a substantial magnetic field, so caution should be exercised in the
placement of low level components such as a tape deck, mixer or mic preamp to avoid inducing noise in the
low level circuitry. Allow several inches of clearance when mounting these components.
AC LINE
The P7000 operates from a 120 volt, 60Hz AC power line. Connection is made by 14 gauge, IEC Type 320,
grounded line cord. For safety considerations only a properly grounded (earthed) receptacle should be used.
If a grounded circuit is not available do not break off the ground pin; use the proper adapter plug for a two wire
receptacle. The power line fuse is mounted on the rear panel of the amplifier. If this fuse blows replace it only
with the same type and rating fuse. The correct replacement fuse value is printed on the rear of the amplifier
and in the parts list.
INPUT
The input jacks used on the P7000 are dual function connectors which accept 1/4" (Tip Ring Sleeve) phone and
XLR plugs. The amplifier will operate with either a balanced or unbalanced signal source. The connector pin-
out is printed on the rear panel of the amplifier.
Balanced Input: 1/4" Tip Ring Sleeve
The 1/4" balanced input jack is connected according to conventional usage with the Tip high (+), Ring
return (–) and the Sleeve ground shield.
Balanced Input: XLR
The XLR balanced input jack is connected according to the IEC and AES Standard, with pin 2 high (+),
pin 3 return (–) and pin 1 ground shield. When preparing to use the amplifier, check the output
configuration of the source unit to maintain the proper signal polarity.
Unbalanced Input
Many popular mixers use unbalanced RCA phono or 1/4" phone jacks for the monitor outputs and can
be used with the P7000 for short cable runs. The specifications for the mixer should give the maximum
cable length it is capable of driving. The return (–) terminal must be grounded when using the amplifier
with the input unbalanced to prevent unstable operation.
Unbalanced Source with Balanced Input
Some systems will have a noticeable amount of residual ground noise when run with unbalanced signal
lines. Better noise rejection can be achieved in these systems by using shielded, twisted pair (balanced)
cable from the unbalanced source. At the source end of the cable, connect an RCA or 1/4" phone plug
with the return (–) wire and shield connected to the ground terminal of the plug. Wire the plug at the
amplifier end of the cable the same as for the regular balanced input connection described above.
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