Mic-PreEminence User Guide
Issue 5, April 1994
Studio Technologies, Inc.
Page 9
NORMAL position, a positive going signal
on microphone input pin 2 will result in a
positive going signal on both pin 2 of the
balanced output connector and the tip of
the unbalanced output. In the REVERSE
position, a negative going signal would be
present on the aforementioned pins. A
small click or pop may be heard over the
line outputs when the output phase switch
is actuated.
Gain Controls
On each channel, a gain control determines
the amount of gain applied to the micro-
phone input signal. In the MIN position
approximately 12dB of gain is added to
the input signal. In the maximum position,
approximately 68dB is added to the input
signal. The two gain controls are completely
independent of each other and cannot be
coupled to track together. The gain control
should be set so that an average input
signal produces the desired balanced or
unbalanced output level. In many situations
the desired average balanced output level
would be +4dBu, and –10dBv for unbal-
anced operation.
The gain control is not a pad that would
reduce the performance of the Mic-Pre-
Eminence; it directly controls the gain of
the Mic-PreEminence input stage. The
headroom available is always the difference
between the maximum output level in the
balanced mode (+30dBu balanced into 10k
ohms) and the sum of the input level and
the gain selected by the gain control. In the
likely case of wanting an average output
level of +4dBu, you would have 26dB of
headroom!
The gain control is really intended to match
the input level with the desired output level.
It is not intended to be used to “ride” the
level sent to the piece of equipment con-
nected to the balanced or unbalanced line
output. The gain control is intended to be
set and left during a particular recording or
broadcast passage.
It is almost impossible to overload the Mic-
PreEminence if the gain control is set to
correctly match the input of the next piece
of equipment in the audio chain. With the
Mic-PreEminence’s wide gain range, even
a +4dBu input signal with the gain control
set for minimum (+12dB) would give 14dB
of headroom before clipping!
Level Meters
The 5-segment LED level meters can pro-
vide assistance in setting the gain controls.
The meter circuitry was designed to have
characteristics somewhere between that of
a VU meter and a peak (PPM) meter. They
are provided strictly as a reference and
shouldn’t force you into setting the gain
controls to give “standard” VU-type read-
ings on the meters. Even if the red LED is
lighting on peak signals, you are most likely
still far from the Mic-PreEminence’s clipping
point; the red LED lights approximately
18dB below clipping! When the red LED
lights, it is telling you that you are operating
in what most people consider the headroom
range.
Output Select Switches
The back panel contains two push
button switches that select which outputs,
balanced or unbalanced, are active.
