Rupert Neve Portico 542 - 500 Series Tape Emulator with Silk - Manual (Page 5)

5
the 542’s tape circuit can significantly impact tone, depending on the position
of the saturation control and the drive level on the tape circuit. As saturation is
increased, low frequency compensation is decreased, and at a drive level of 5
the soft clipper enters the circuit. Finding the best balance point between low
frequency response, total harmonic distortion, and desired soft clipping require
playing with a combination of the saturation, trim and blend controls, and may also
include using dynamics processing and proper gain staging before the 542.
As a rough guide, we recommend starting with an input signal from around
2-10dBu and applying saturation, 15 / 30 IPS, Silk, and blend to taste. It does
however also behove the engineer to experiment with the balance between the
pre-tape signal level and the level of the saturation control to find the best results
for each source.
To get a better idea of what is happening at different saturation and “Tape Head”
levels, look through the frequency response and THD by frequency response graphs
in the Technical Specifications section at the end of the manual.
Also, like a real tape machine, the flux loops in the “True Tape” circuitry can pick
up signals from strong nearby magnetic fields (The most likely sources are nearby
power supplies, power amplifiers and computer monitors). Although, we have
shielded both the unit as a whole and the tape circuit to minimize stray inductance,
if you have issues with hum when engaging the tape circuit, try moving the 542 to
other spots away from magnetic field radiators until the hum subsides.
542 FEATURES
TAPE IN
Sends the signal through the “True Tape” circuitry, which is affected by the
saturation, blend and 15 / 30 IPS controls.
TRIM
Provides +/– 12dB adjustment of level on incoming signal levels, prior to the tape
circuit.
SATURATION
Controls the signal level being sent to the magnetic Tape Head. As the saturation
level increases the level on the “record” head rises, and the replay gain is reduced
so that the overall output signal level remains more or less constant. In a real tape
recorder, you would adjust the record and replay gain controls separately, however
in the 542 the record and replay gain controls are coupled so that the overall signal
level only varies as the “Tape” saturation level changes. As you approach maximum
saturation setting, the output signal level will drop due to the effect of extreme
saturation and soft clip.
Additionally, to compensate for low frequency loss at low “record head” levels,
the saturation knob also controls a low frequency compensation circuit that boosts
low frequencies more at low saturation levels, and tapers off at higher levels. This