10 • POWER 750
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.
Don’t forget about your amplifier after it has been installed in a rack case! Continuous transportation and vibration can cause screws to become
loose, both on the Power 750 and with your rack case rails. We recommend that at least once a month you remove the Power 750 from the case
and tighten all outside screws (especially the rear mounted screws holding on the front panel) and wipe off the outside of the chassis with a damp
cloth (to help keep that chrome nice and shiny!). Then check all the connections in your rack case and reinstall the unit.
ELECTRICAL AND GROUNDING CONSIDERATIONS
In a rack system with a large power amplifier such as the Power 750, placement of effects units and preamplifiers with respect to the power
amplifier may be important as hum induction may occur. Generally speaking, install a preamplifier so that it is farthest away from the power amplifi-
er with line level effects units, tuners, etc., in between. Whenever possible, leave an empty rack space between the power amplifier and other
accessories in the same rack.
All patch cords should be made as short as possible using high quality shielded cable and plugs. Placement of patch cables should not run next to
AC power cords and should not be routed in between different components. In other words, do not run a patch cable from the front of a preamplifi-
er over the top or under the bottom and then to the rear input of a power amplifier, as this can cause "hum" in the system. If you must run patch
cables in this fashion, experiment with the routing so that ideal placement is achieved.
Another consideration in a rack system is a ground loop caused by the chassis' of several pieces of equipment electrically "tied" together by the
metal rack rails. Some equipment is built with this situation in mind, such as the Grand Prix Preamp from SWR. It comes with an option of separat-
ing certain electrical grounds from chassis earth grounds thus isolating the chassis from the inner workings. This method is far superior than that
of using a three prong to two prong adapter on your AC cord. These adapters "lift" the earth ground from your chassis and could make for an
unsafe condition.
If you are experiencing a system grounding problem (each piece of equipment works good by itself, but connecting them together causes undesir-
able hum), and using a ground adapter on one piece of equipment solves the problem, consult the manufacturer of that piece of equipment to see
if there is a way to isolate the secondary grounds from the primary or chassis earth ground. Feel free to contact our service department if a prod-
uct from SWR is in question. (In situations with intractable ground issues in a complicated, multi-component rig, we here at the factory have found
the Hum Eliminator by Eb-Tech to be an invaluable and inexpensive accessory available at most Guitar Centers and other large M.I. retailers.)
We sincerely hope that the Power 750 exceeds your expectations in the area for which it was chosen.