Drawmer 1962, Руководство оператора

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1962 OPERATORS’ MANUAL 9
MICROPHONE PRE-AMPLIFIER
The microphone input stage is based around an advanced, discrete component design,
characterised by extremely low levels of noise and distortion. The audio performance is
significantly better than what is normally achieved by the input stage of a typical, high
quality recording console. When the tube and EQ sections are out of circuit, the mic preamp
provides a high quality, minimum signal path to the output, making it ideal for direct
connection to a tape machine or, if the D62 digital interface is installed, to the digital input
of a digital multitrack recorder, DAT machine or hard disk recorder. The tube and EQ stages
may be switched into circuit for applications where it is desirable to 'enhance' the signal
prior to recording.
Input Gain:
When the Input Select switch is set to either MIC or 48V(MIC), the Input Gain
control is fully variable over the range -25dB (attenuation or ‘pad’ for powered
microphone systems) through to +60dB; the gain setting may be read off
using the white coloured graticule around the Gain control. The input level
meter must be monitored while adjusting the input gain so that
average
programme level is between -18dBfs and -12dBfs while the highest peak
signal level
never exceeds 0dBfs. This will permit a programme headroom
of about 18dB (or approximately 3 bits of digital data). If the Peak LED
illuminates, the gain is too high and should be reduced accordingly.
Phase Rev:
Depressing this button inverts the phase of the microphone input signal
(only). Normally, a positive pressure at the microphone diaphragm produces
a positive voltage at pin2 of the XLR output socket, but when Phase Rev is
active, the inverse is true.
Use of the Phase Rev feature is usually required only in multi-mic situations
where phase anomalies or arrival time discrepancies need to be
compensated for. It is advisable to check for mono compatibility when using
phase reversal within a multi-mic arrangement.
AUXILIARY INPUT
To facilitate the connection of instrument sources, an unbalanced Auxiliary input jack is
provided. This drives a sophisticated instrument input stage which offers control over both
gain and brightness. The Aux input has a 470K
Ω impedance and is suitable for use with
both active and passive guitar pickup systems, electronic keyboards and similar sources.
Though the 1962 is not designed to replace a dedicated guitar preamplifier, the Gain
controls may be used to deliberately overdrive the input stage, which respond in a similar
way to a tube instrument amplifier. For direct recording using significant amounts of
overdrive, it is recommended that a speaker simulator be connected between the 1962 and
the recorder, and that the sound be monitored post speaker simulator. A conventional EQ
is not suitable for emulating the transfer characteristics of a guitar stack or combo system.