Alto Acom2, User Manual, Page: 4 / 60

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Limiter
21. Threshold control - Controls the level of the Limiter.
22. Limiter LED - Lights up when the Limiter function is activated.
REAR PANEL CONTROLS
23. Power connector - Connect the included power cable here.
24. Audio in - Balanced 1/4” TRS jack and XLR input connectors.
25. Audio out - Balanced 1/4” TRS jack and XLR output connectors.
26. Operating level control - Sets the operating level to either -10 dBV or +4 dBu.
27. Sidechain send - 1/4" unbalanced jack to route audio to an external processor.
28. Sidechain return - 1/4" jack processes the return signal sent from an external processor.
COMPRESSOR CONCEPTS
Digital audio equipment usually has a very high dynamic range: up to 125 dB. However, the dynamic range
of analog equipment is about 25 dB less. Using tapes and vinyl records further reduces the dynamic range.
SIGNAL-TO-NOISE RATIO
All electronic equipment produces some noise when current flows through its conductor. The noise is further
amplified when it occurs across the whole spectrum of audio. Even "low-noise" components still have some
residual noise. For example, most tape recorders have a signal-to-noise ratio (SNR) of 70 dB or less, a level
that most of today's listeners would recognize as low-quality.
DYNAMICS
The chart below shows the dynamic ranges of various devices compared to the human ear.
Ear Microphone Power Tape Radio Cassette
Preamp Amplifier Recorder Recorder
21 21
22 22
1
2
3 4
5
6
7
8 9
10
11
12
13
14 15
16
17
18
19
20
21
22
23 23
24 24
25 25
26 26
27 27 28 28
24 24
25 25
26 26
27 27 28 28