SWR POWER 750 Bedienungsanleitung Seite 12

SPEAKER FUSE
The speaker fuse is provided to protect your speakers in the unlikely event of a power amp failure or incorrect connection procedure. Size and
rating of the fuse is 3AG, 15 amp, fast-blo. Do not defeat the purpose of this feature by using a higher rated fuse. The speaker fuses can open if
there is a fault in the speaker cable or even the speakers themselves. Therefore, it is always wise to carry extra fuses at all times. Do not defeat
the purpose of this feature by using a fuse of a higher amperage. It will only cause further problems if a fault lies in the system.
LINE (MAINS) FUSE
The size and rating of the Line Fuse is T10A (slo-blo) for 100–120V models and T5A for 220–240V models. It serves to protect your amplifier's
power supply and transformer from large voltage spikes caused by an external source, and also serves to protect the transformer in the unlikely
event of a power supply failure. NEVER replace this with a fuse of a higher rating as it will void your warranty.
A/C CORD RECEPTACLE
This receptacle accepts a standard A/C power cable (supplied with the Power 750), the same kind used with almost all current musical, profes-
sional and household electronic devices. If this cable is misplaced or lost, a replacement can generally be found almost any appliance store,
supermarket or the like. Make sure that the AC cord is plugged firmly into both the amplifier and the wall socket. If your cord ever becomes frayed
or split, replace it IMMEDIATELY.
NOTE: The rating for the A/C cable is 3 conductor, 10 amperes MINIMUM. If replacement is necessary, or if you wish to buy a longer cable, look
for the rating on the cable and be sure it is at least 10 amps.
COOLING FAN DEFEAT SWITCH
With the Fan On/Off switch in the "On" position, the internal cooling fan will run at slow speed when the internal heatsink temperature is below 85
degrees C and at high speed when the temperature is above 85 degrees C. The Fan On/Off switch should be left in the "On" position for normal
operation.
With the Fan On/Off switch in the "Off" position, the internal cooling fan will be off when the internal heatsink temperature is below 85 degrees C
and at high speed when the temperature is above 85 degrees C. SWR recommends that the "Off" position be used ONLY in situations where fan
noise might be audible and therefore problematic—such as when miking in a recording situation.
A FEW WORDS CONCERNING HEAT
One of the most asked questions about our amplifiers is why they tend to get warmer than other amps. The chassis of your amplifier can get quite
warm during normal usage. This is especially true if you are are driving the amplifier at its minimum impedance. This is because a 4 ohm imped-
ance introduces the least efficient condition possible for the unit (ie: power drawn from the outlet in relation to power produced in the speakers).
The difference in these two figures can be quite high,
Furthermore, most musical instrument amplifiers on the market today use steel for their chassis', which in most cases is considerably cheaper
than aluminum and does not conduct heat as well. The Power 750 utilizes an aluminum chassis (with the exception of the chromed front panel)
which is a better conductor of heat. This results in the chassis acting as a heatsink - drawing heat away from internal heat-producing components,
thus extending their life. In this manner we feel we have produced a more reliable amplifier, however, at the same time, the chassis of the Power
750 will get warmer than a similar amp chassis that is made of steel.
The one condition you should be aware of is if the power amplifier in your unit becomes "over-biased." This condition can be recognized by turn-
ing your amplifier on and letting it sit "idle" (without speakers plugged in and without playing it). If your unit starts getting hot under these condi-
tions, it may be over-biased. This situation should be attended to and can be easily remedied in about 15 minutes by a qualified service technician.
A power amp can become over-biased through continuous vibration or by any large jolt received in shipping, etc.
RACK MOUNTING INSTRUCTIONS
To preserve the beauty and reliability of your amplifier, we recommend that you install your amplifier in a rack case. The Power 750 is completely
ready to be rack mounted and needs no additional parts or accessories other than the rack screws and the case itself.
The Power 750 takes up three full rack spaces (5"). If the rack in which you mount the Power 750 requires that the rubber feet on the bottom of
the chassis be removed, please remember to keep the screws handy in case you wish to reattach the rubber feet at a later date.
The Power 750 should be mounted as close to the bottom of the rack case as possible. If you must mount the Power 750 in an area of the rack
other than the bottom space, a piece of wood or similar solid material should be installed between the bottom of the rack case and the bottom of
the amplifier to prevent flexing of the amplifier's chassis. Severe or constant flexing of the chassis can damage the amplifier and is not covered
under warranty.
12 • POWER 750