Rupert Neve Portico 5012 - Duo Mic Pre-Amp - Manual (Page 5)

5012 DUO MIC PRE
4
High Pass Filter
The High pass filter is a valuable aid in any signal chain but particularly so in a microphone
preamplifier. Signals between 20 and 250 Hz can be attenuated, leaving the range above this
unaffected. This gets rid of building rumble, air handling motor hum etc.
Meter
An eight segment LED bar-graph meter is fitted for each channel, calibrated in dBu as follows:
- 30 dBu, - 18dBu, - 12dBu, -6dBu, + 4 dBu, + 10dBu, + 16dBu, + 22dBu
With reference to the balanced output signal level.
The input level can be determined by reading the Meter indication, then subtracting the Gain
settings of the Sensitivity switch and the Trim control.
For example, if the meter is reading + 10 dBu, with the Trim control at, say, +2 and the main
Gain switch is at 42, the level of the input signal is 10 - 42 - 2 = -34 dBu.
Main Output
The main output signal comes from the output transformer secondary which is balanced and
ground free. A ground free connection guarantees freedom from hum and radio frequency
interference when connected to a balanced destination such as the input to another Portico module
or one of the many high quality vintage modules still in current use.
However the transformer may be used with one leg grounded without any change in
performance. It is not necessary to “ground” one leg at the Portico output. It would normally get a
ground connection when fed to equipment that is not balanced.
Maximum output level is + 25 dBu, which provides a large margin over and above the likely
maximum requirement of any destination equipment to which the 5012 is connected.
Buss Output
The To Buss output is unbalanced and has a high impedance output. It is intended for use with
the Portico Buss Amp/Monitoring modules. A TRS patch cord is used to connect the 5012 Buss
output to one of these bussing modules. The Monitor connection is derived pre mute on the 5012
and will produce a signal at the output of the buss modules that is equal in level to that at the 5012
output. The Monitor output cannot be used for any other purpose.
Silk
Much could be written about this feature, suffice to say, that it gives a subtle option to enhance
sound quality in the direction of vintage modules. The Silk button reduces negative feedback and
adjusts the frequency spectrum to provide a very sweet and musical performance. We suggest you
try it and make your own judgment.