Nilfisk-ALTO CLE4.0 Air Compressor User Manual


 
5
Chart. 1 The dynamic range capabilities of various devices
Chart. 2 The interactive relationship between the operating level and the headroom
So the operating level must be as high as possible but not high enough to generate distortion.
Tricky uh?
There is a very easy way to obtain this. With the volume knob in hand you increase the volume
during low passages and decrease the volume during loud passages. Unfortunately even the Great
Houdini would not be fast enough to monitor carefully the speed of the musical signal and it would
be impossible to detect signal peaks and consequently levelling them out. Manual control is therefore
out of question. The answer is AGC (automatic gain control); a device that will monitor the signal in
real time and that will adjust the gain for the best S/N ratio without producing distortion. So, the name
of this device is "Compressor/limiter".
2.1.3 More technical stuff about Compressor/Limiters
Try to measure the dynamic range of musical instruments. You will find out that your ear will handle such range.
Your audio equipment will not and distortion and overloading will be generated. To avoid these, compressor/
Limiters will be used. Both Compressors and Limiters more or less limitdo the same job but Limiters brutally
the audio signal above a set threshold, while Compressors andhandle signal in a much more civilised way
over a wide range of levels. If an audio signal any audioexceed the threshold set by the User the limiter will kill
signal above that threshold. exceed aPeriod! Also Compressors perform their function when the audio signal
certain threshold withbut the signal is not killed brutally. The audio signal will be reduced in gain in proportion
the amount above the set threshold.
Clipping Signal heavily distrortedClipping Signal heavily distrorted
Low level signal drowned out by noiseLow level signal drowned out by noise
Clipping Aera
Noise Aera
2.2 Voltage Controlled Amplifier (VCA)
The VCA is the soul of the CLE 4.0 and it is one of the best components available today in his category thanks to its
excellent performances in terms of distortion, linearity, noise and temperature stability
2.3 Inputs
2.3.1 Take it easy: Balanced Inputs
To make your life easy and clean we have provided CLE 4.0 with electronically balanced inputs. Even if
you operate at high signal levels, hum and noise will be reduce automatically. There is also a servo-function
that will automatically adjust the internal level when unbalanced connectors are detected. The correction
if of 6dB and it will avoid differences in level in between input and output signal.