Rack Mounting And Cooling; Turn-On Procedure - Avalon VT-737SP Operation Manual

3.4 Rack Mounting and Cooling

The Vt-737sp is designed to be mounted in a
standard 19" equipment rack. As vacuum tubes
and Class A circuitry generate heat, it is highly
recommended that an additional rack space
above and below the unit be kept empty to
allow for adequate cooling. Avalon Design has
developed 1U ventilation panels (VP-1) specfi-
cally to keep your rack-mounted gear cool.
Avalon VP-1 vent panels
Be sure that the top and bottom of the unit is
not obstruced and air is allowed to flow easily
through the chassis. If the unit is not
rack-mounted, be sure to place supports under
the unit to allow air to pass underneath. Never
leave any obstruction on top of the unit (such as
papers or books) blocking ventilation slots.
Also, be sure that the heat sink mounted on the
rear panel of the chassis has adequate clear-
ance from the equipment enclosure and any
adjacent equipment. In electronic equipment,
excessive heat is the cause of most component
failures. A little extra precaution to ensure
proper ventilation can help avoid equipment
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Always use all four front panel-mounting
holes when mounting the Vt-737sp in a rack
enclosure. If not shipped in its original pack-
ing, the Vt-737sp should be transported in a
floating-type shock-mounted flight case.
Although the Vt-737sp is well shielded against
moderate electrical and magnetic feilds, care
should be taken to avoid areas that are in
proximity to large motor or power transform-
ers. Locations near sources of high RFI (radio
frequency interference) such as computers or
digital effects devices should also be avoided.
Because of the microphonic nature of vacuum
tubes, areas of extreme vibration or sound
levels should also be avoided.

3.5 Turn-on Procedure

The Vt-737sp is designed with a "soft-start"
feature that slowly brings the unit to life when
the unit is powered on. This feature ensures
that there is no strain on the electronic com-
ponents when it is activated. It takes approxi-
mately 45 seconds for the unit to go through
the "soft-start" turn-on procedure.
When the Vt-737sp is switched off or during
the "soft-start" turn-on procedure, it is in hard
wire bypass mode and the unit will pass signal
utlizing a hard wire relay but none of the con-
trols will operate (line in to line out).
Allow the unit to warm up for at least thirty
minutes prior to use. This allows the compo-
nents time to come up to temperature and
stabilize before recording begins.
It is recommended that the unit be turned
off during periods of "non-use" greater
than 4 hours.
Avalon Vt-737sp Operation Manual
Safety and
Grounding