Pr
oFX4v2
8
ProFX4v2
ProFX4v2 Front Panel Features
Phantom Power
Most modern professional condenser mics require
48V phantom power which lets the mixer send
low-current DC voltage to the mic’s electronics
through the same wires that carry audio. (Semi-pro
condenser mics often have batteries to accomplish
the same thing.) “Phantom” owes its name to an ability
to be “unseen” by dynamic mics (Shure SM57/SM58,
for instance), which don’t need external power and
aren’t affected by it anyway.
The ProFX4v2 mixer’s phantom power is
globally controlled by the phantom power
switch (meaning that phantom power for
both mic inputs is turned on and off together.)
Never plug single-ended (unbalanced)
micro phones or ribbon microphones into
the mic input jacks if phantom power is on. Do
not plug instrument outputs into the mic input jacks
with phantom power on unless you know for certain it
is safe to do so.
4. Line / Hi-Z Switch
To connect a guitar directly to the mixer without
using a DI Box, press this switch in first; then connect
the output from the guitar to channel 1's 1⁄4" TRS
input. The input impedance is optimized for direct
connection and high-frequency fidelity is assured.
In the out position, channel 1's 1⁄4" TRS input
becomes a line input just like the other mono line
inputs.
To use guitars or other instruments on other
channels, you will need to use an external DI box
first. Without the DI box – or if this switch is not
pressed in – guitars may sound dull and muddy.
3
5
4
6
Connections and Channel Strip
The vertical channel strips look very similar
and have only a few differences between them.
Each channel works independently and just controls
the signals plugged into the inputs directly above them.
3. Mic Inputs
ProFX4v2 mixers use 3-pin female XLR connectors
on all microphone inputs, with pin 1 wired to the
grounded (earthed) shield, pin 2 wired to the high
(hot or positive polarity) side of the audio signal
and pin 3 wired to the low (cold or negative polarity)
side of the signal.
These female XLR connectors accept balanced
mics or line level inputs from almost any type of
source. The Vita mic preamps feature higher fidelity
and headroom rivaling any standalone mic preamp
on the market today.
We use phantom-powered, balanced inputs just like
the big mega-consoles, for exactly the same reason: This
kind of circuit is excellent at rejecting hum and noise.
Professional ribbon, dynamic, and condenser
mics all sound excellent through these inputs.
The mic/line inputs will handle any kind of level
you can toss at them, without overloading.
Microphone-level signals are passed through the
mixer's splendid microphone preamplifiers to become
line-level signals. They are wired as follows, according
to standards specified by the AES (Audio Engineering
Society).
XLR Balanced Wiring:
Pin 1 = Shield (ground)
Pin 2 = Positive (+ or hot)
Pin 3 = Negative (– or cold)
2
3
1
SHIELD
COLD
HOT
SHIELD
COLD
HOT
3
2
1
