Rupert Neve Shelford 5052: Mic Pre / Inductor EQ - Manual (Page 10)

due to possible converter calibration variables. The 5052 level meter is calibrated
for dBu, and the red LEDs may not necessarily match up with the destination
device.
MIC IN
XLR female transformer balanced floating input associated with the Mic position of
the front panel input switch. Pin 2 high, 10 k Ohm input impedance.
LINE IN
XLR female transformer balanced floating input associated with the LINE position of
the front panel input switch. Pin 2 high.
EQ IN
XLR female balanced input that feeds the EQ section when the TO EQ switch is
disengaged. Pin 2 high, 10 k Ohm input impedance.
MIC OUTPUT
XLR male transformer coupled floating output. Pin 2 high.
MAIN OUTPUT
XLR male transformer coupled floating output. Pin 2 high. The main output is the
only output that incorporates the Silk and Texture Circuitry.
POWER
Proprietary 4 pin polarized input for +24 and -24V DC power input. This power
requirement and connector is meant to be used with a special shared power supply.
Be sure to align the key in the cable to the keyway in the unit and power supply
socket connectors.
A NOTE ON DISTORTION
The human hearing system is a remarkably complex mechanism and we
seem to be learning more details about its workings all the time. For example,
Oohashi demonstrated that arbitrarily filtering out ultrasonic information that
is generally considered above our hearing range had a measurable effect on
listener’s electroencephalo-grams. Kunchur describes several demonstrations
that have shown that our hearing is capable of approximately twice the timing
resolution than a limit of 20 kHz might imply (F=1/T or T=1/F). His peer reviewed
papers demonstrated that we can hear timing resolution at approximately with 5
microsecond resolution (20 kHz implies a 9 microsecond temporal resolution,
while a CD at 44.1k sample rate has a best-case temporal resolution of 23
microseconds).
It is also well understood that we can perceive steady tones even when buried
under 20 to 30 dB of noise. And we know that most gain stages exhibit rising
distortion at higher frequencies, including more IM distortion. One common IM
test is to mix 19 kHz and 20 kHz sine waves, send them through a device and then
measure how much 1 kHz is generated (20-19=1). All this hints at the importance
of maintaining a sufficient bandwidth with minimal phase shift, while at the
same time minimizing high frequency artifacts and distortions. All of the above
and our experience listening and designing suggest that there are many subtle