Aphex A PRE 500 - Manual (Page 4)

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The A PRE 500 mic pre uses a custom designed CineMag input
transformer and a Jensen JT-11DL nickel output transformer. This
provides the cleanest possible balanced output signal.
2.0 INTRODUCTION
3.4 -26dB PAD
When the input signal is clipping the preamp
with the input trim control turned all the way
down, the -26dB pad can be engaged to solve
the problem.
3.5 PHASE
The Phase button will invert the input signal
180 degrees. Using two microphones on
the same source can cause phase problems.
Reversing the phase of one of the microphone
signals will often clear up the problem.
3.6 75Hz HIGH PASS FILTER
Engaging the 75Hz HPF will roll off all the
freqencies below 75Hz. It’s a good idea to use
the HPF when recording voices or instruments
that don’t have much low frequency content.
Only capturing the relevant frequencies will
provide a cleaner mix later on.
Condenser microphones require power to function. Some-
times a microphone will use internal batteries, but usually the
required power is provided by the mic pre. Turning on the
Phantom Power will send power down through the cable to
power the microphone. Be careful though, as ribbon micro-
phones and some older dynamic microphones can be dam-
aged or destroyed by phantom power.
3.0 CONTROLS & INDICATORS
3.1 TRIM CONTROL
The Trim control boosts the input signal from
+26dB to +65dB.
3.2 INPUT METER
This 20 segment input meter provides visual
confirmation of the input signal level. The top
three LEDs of the meter are red. When the
input signal reaches the top red LED, the input
signal wil clip.
3.3 OUTPUT LEVEL SWITCH
The output level can be set to +16dB, +20dB
and +24dB. You will need to know the maxi-
mum input level of the next device in the
audio chain to set this properly. Most profes-
sional audio devices can handle a +24db input
signal without issue.
However, some inexpensive computer audio
interfaces have a maximum input level of only
+4dB. Many audio devices also offer a -20dB
pad to address these kind of issues.
3.7 48V PHANTOM POWER