Arturia TridA-Pre, Руководство пользователя

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4. TRIDA-PRE OVERVIEW
As we said already in the Introduction, the Trident® A was particularly noted and praised
for its preamps and the unusual and colorful EQ. A unique characteristic was a series of
three high pass filters at -18dB per octave and three low pass filters at -12dB per octave,
arranged at the ends of the EQ section. The switches to those filters could be pushed in
simultaneously, offering distinct cut filter combinations with unusual filter curves.
The rest of the EQ section allows four frequencies at any one time, arranged as two Shelf
bands and two Bell (Peak) bands, with switchable but fixed values.
Also, the EQ section was inductor-based and that design made it add some odd peaks and
parasitic phasing-induced frequencies which are part of the character.
The plug-in works as a Single Channel or as a Double Channel, according to the audio
channel it is inserted on. In Single Channel we just have Mono mode, but in Double Channel,
we can use the plug-in in Stereo mode, Mid/Side mode and Dual Mono mode.
4.1. What is a preamp?
A preamplifier (preamp or simply "pre") is a device that takes care of the first stage of
amplification. It is usually designed to boost a weak electrical signal to "working level", to
make it strong enough to be noise-tolerant and for further processing, for example in a
mixing desk. The working level is usually called "line level".
Many of us probably still remember the days of vinyl records. Vinyl records were played by
turntables, a device which had an output with a completely different impedance than, for
example, a tape recorder. The turntable output signal was much weaker. To drive it to a level
strong enough to be audible meant that it had to pass through a circuit that would amplify
it to a level where it could be passed to the main audio amplification circuit. More than that,
the circuit also had to transform the tone, in order to decode the special RIAA encoding tone
curve. Without this previous stage, the signal would be weak and distorted harmonically.
This circuit was (is) a preamplifier, and was usually part of any Hi-Fi amplifier (those special
inputs labeled "phono", which seem to be coming back as of lately). It should be mentioned
that Arturia's AudioFuse audio interface also features a microphone preamp circuit, and it
even features the special RIAA preamp we just mentioned.
But there are other kinds of preamplifiers, that do other things. The preamp devices that
brought us to this point are those typically used to amplify signals from audio sources
such as microphones and instrument pickups. Because of this, preamplifier circuits are now
usually built into audio mixers (and are included in many computer audio interfaces too).
But it wasn't always like this. There was a time when preamps were separate units that
received the signal from microphones and delivered it to the mixing circuit. Then they
became modules that could be plugged into those mixers. Now, they are simply standard
equipment. But there are still many other devices that use preamp circuits besides mixers,
as electric guitar and bass players know very well.
16 Arturia - User Manual TriA-Pre - TridA-Pre OVERVIEW