Facilities And Controls; Discrete Class A Pre-Amp - Focusrite TwinTrak Pro Mode D'emploi

9. Increase the LEVEL control, checking the input level meter LEDs and ensuring the
red O/L LED does not illuminate, except occasionally and briefly when the loudest
signal is present. Note that the input is graded in dBfs, so a level of around 0dBu will
only illuminate the first 2 LEDs.
See www.sospubs.co.uk/sos/may00/articles/digital.htm for more about dBu
and dBfs.
10. If using a microphone, ensure that the microphone placement is at its best. Before
you start recording, alter the position of the microphone until you get as close as
possible to the sound you want. Note that moving the microphone may have an effect
on the level of the signal entering the TwinTrak Pro, requiring an alteration to the
LEVEL setting.
11. You can now eliminate any problematic mid frequencies by using the MID
SCOOP EQ section. See page 5 for more information on the MID SCOOP EQ.
12. The OPTICAL COMPRESSOR will help control the dynamics of the signal
passing through the unit. See page 6 for more information on the OPTICAL
COMPRESSOR.

FACILITIES AND CONTROLS

- Turns the unit on. We recommend that the unit be powered
POWER (switch)
up before connecting to any equipment that it is feeding, to avoid clicks or thumps
which may harm output devices.

DISCRETE CLASS A PRE-AMP

This part of the unit is a pre-amplifier, used to amplify the incoming signal being fed
to the MIC INPUT or INSTRUMENT INPUT to a suitable level before any further
processing is applied.
-
This is an XLR connector that allows you to connect a microphone
MIC INPUT
to the unit. If using the TwinTrak Pro's mic pre and feeding the output into a mixing
console, bypass the console's own mic pre and connect the TwinTrak Pro output to
the mixing console channel's line input. This will mean the superior TwinTrak Pro
mic pre is used to process the signal, avoiding unwanted noise, distortion and
colouration from an inferior mic pre. Always avoid routing the TwinTrak Pro's mic
pre into a second mic pre, as this will produce greatly inferior results.
- This provides +48V of phantom power for condenser
+48V (switch)
microphones (affecting the MIC INPUT only). If you are unsure whether your
microphone requires phantom power, refer to its user guide before connecting, as it is
possible to damage some microphones (most notably ribbon microphones) by
providing them with phantom power.
- This provides a pleasant boost in the high-end frequencies
AIR (switch)
(affecting the MIC INPUT only). The exact boost frequency is dependent upon the
microphone being used. This effect can simply be described as 'adding air' to the signal
and enables the pre-amp to recreate the open and airy qualities of more expensive
transformer-based pre-amps.
- Rotating the IMPEDANCE control alters the input
IMPEDANCE (knob)
impedance of the mic pre (affecting the MIC INPUT only). By adjusting the
impedance of the TwinTrak Pro's discrete Class A transistor input, the performance of
both the pre-amp and the microphone connected can be tailored to set the desired
level and frequency response. For more information see the MIC PRE-AMP INPUT
IMPEDANCE section on page 9.
-
These are high impedance 1/4" jack inputs that allow
INSTRUMENT INPUT
you to connect an electric guitar or bass guitar to the unit without loading the pickups,
and without the need for a DI box.
ENGLISH
4