ES02 combines two functions in to a single module:-
- for scaling external audio signals to EuroSynth audio levels
Detector - also known as an Envelope Follower and which extract
amplitude information from complex audio waveforms. The resulting
dc voltage often drives non-linear stages, such as voltage-controlled
amplifiers or filters.
Serge Preamp and (new) Envelope Detector provide an exceptionally
responsive link between external audio signals and the EuroSerge
synthesizer modules. The key to this responsivity comes from the
fact that the detector was designed to respond to the POWER rather
than to the AMPLITUDE of a sound. Human perception of loudness is
proportional to the POWER content of a wave, rather than to its
Detecting the AMPLITUDE of a signal produces an inaccurate envelope,
sometimes too soft, and most of the time too loud. The ES02 detector
is exceptionally accurate and outputs a control voltage envelope
that is directly proportional to the perceived loudness of an input
signal. It operates over a very wide dynamic range, in excess of
70db, (or the difference between a whisper and a subway train at
15 feet!). The output is accurately log-linear at 12db/V, a taper
which mates perfectly with the control characteristics of the ES78
VCA. Thus it is possible, for example, to control the loudness of
a synthesizer sound by the sound envelope of a locomotive, a dog
barking, or a voice going from a whisper to a shout. The effect
is especially remarkable because of the accuracy of response:
the whisper is really a whisper, and the shout a shout.
Preamplifier accepts a wide variety of inputs:-
In - accepts outputs from high-output microphones in the range 200
to 1000 Ohms (such as most electret microphones), with a sensitivity
suited for close-miking applications such as instrument or voice
In - accepts outputs from transducers such as guitar pickups and
contact microphones. It is also suited for amplifying low-level
signals from tape machines, tuners etc.
the 3.5mm variant the [OUT] output of the preamplifier is normalised
to the [IN] input of the Detector allowing access to both output
signals without patching.
for various microphones and audio sources can be adjusted over a
very wide range using the Preamp's [GAIN] control (but note, it
will not cut the gain to zero).
[Lo-Z IN] and [Hi-Z IN] inputs are both 3.5mm jacks.