Peavey PVXp 12 Instructions De Fonctionnement page 16

With the Level control adjusted fully clockwise, gain is at maximum and the input sensitivity is 0.54 V RMS for
full-rated output with the 1/4" TRS jack, and 0.12 V RMS with the XLR portion of the jack. When driving the
PVXp 12 from a mixer, it may be advantageous to reduce the input sensitivity by turning the Level control to
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the halfway point. The PVXp 12 will now more closely match a typical power amp.
If the mixing board indicates clipping of its output signals, then all of the PVXp 12 power capability is not being
utilized cleanly. Clipping the signal before it gets to the PVXp 12 is not optimal. Reduce the mixer output
level and turn up the Level control on the PVXp 12. The amplifiers in the PVXp 12 are equipped with DDT ,
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and the LED indicator will show when DDT has engaged. If the sound seems heavily compressed, check these
indicators; if it is blinking RED more than occasionally, then the drive level from the mixer (or the Level control
on the PVXp 12) needs to be reduced.
When first turning on the sound system, switch on all upstream electronics first, then the PVXp 12 with its Level
control fully counterclockwise (all the way down). Begin checking levels with the mixer output level controls
all the way down, and bring them up slowly with the PVXp 12 Level control set to the desired setting (one-third
recommended to start).
It is not good practice to turn the Level control on the PVXp 12 all the way up and then try to control level only
from the mixer; this approach would tend to pick up excess noise. The best practice would be to run a "hot"
signal from the mixer down the cable to the PVXp 12, and then turn the PVXp 12 Level control up only as much
as necessary to reach the full desired output. With this approach, it is necessary to verify the mixer output is
not clipping.
DisconnectinG Ac poWer to tHe pVXp 12
We recommend that the Power switch (3) be used to turn the unit off first, and then the AC power cord can be
removed. This minimizes stress to the power amplifiers and the transducers from turn-off transients. The power
switch has an arc suppression capacitor to help during turn-off, and tends to make a clean disconnect from
the AC power, while the power cord IEC connector can make intermittent contact before finally becoming fully
disconnected, e.g., as when wiggling the cord.
troUBLesHootinG
No Output at All
First, make sure the unit has AC power and is turned ON. Make sure the LED on the power amp module is
illuminated.
If not, make certain the ON/OFF switch (3) is in the ON position and check the IEC power cord connection (2)
by ensuring it is fully engaged and seated. Make certain the AC line cord is plugged into a working AC outlet.
Finally, check the breaker (1). (See the Rear Panel: Breaker section, for safety instructions.)
Once assured your unit is getting AC power, check that the PVXp 12 is getting a signal. Temporarily disconnect
the cable running to its inputs and connect it to some other device capable of reproducing the signal (i.e., a
power amp and speaker). If this produces a signal, make sure that all Level controls being used have been
turned up to a satisfactory level (one-third to halfway).
If the PVXp 12 has been subjected to direct sunlight or excessive heat, the built-in thermal protection may have
been triggered. If so, turn off the PVXp 12 and let it cool for a sufficient amount of time.
If there is still no output, contact your authorized Peavey dealer or the Peavey International Service Center.
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Hum or Buzz
If the PVXp 12 is producing a hum or buzz, this can be AC outlet related. Try plugging the PVXp 12 into a
different AC outlet. Sometimes, if a different circuit (breaker) is used for the mixer and for the PVXp 12, it can
cause hum problems. Unless it is not practical, it is best to use the same wall outlet (breaker) to supply power
to both the mixer and the powered speaker.
Ensure that shielded cables have been used to route the signal to the PVXp 12's input. If speaker cables with
1/4" plugs are used as input cables instead of shielded cables, they will be prone to hum or buzz.
Hum may be ground loop related. It may be helpful to lift the shield ground (Pin #1) on a balanced cable at the
PVXp 12 end. Check any input changes carefully by first turning down the Level control, before plugging and
unplugging cables, or lifting the shield ground at the speaker end.