TerraTec Phono PreAmp iVinyl, Руководство пользователя

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20 PhonoPreAmp iVinyl (English)
6. Descratcher
The Descratcher function effectively removes pops and crackling noises from old vinyl and
shellac records as well as from audio files in which the tone quality has been decreased dur-
ing recording because of switch noise, digital crosstalk or thyristor humming.
The Descratching algorithm consists of two parts: the Declicking Filter and the Decrackling
Filter . While the Declicking filter is running, usually to remove relatively loud clicks and pops
from old vinyl records or switch noise from digital or analog audio devices, the Decrackling
filter removes any remaining, usually quiet but dense crackling.
The higher you set the Declick parameter, the more cracking noise is removed. When it is set to
0, the filter lets through nearly all cracking noises. To remove cracking noises from soiled vinyl
records, a
Declick value of about 50 is good in most cases.
A typical popping noise in a signal from a vinyl record (left) and the reconstructed signal (right).
The higher you set the Decrackle parameter, the more crackling noise is removed from the
original. The highest setting, nearly 100, dampens the actual input signal. In general, this pa-
rameter can be set to 80 without resulting in any audible depletion of the original sound. In
some cases, an extremely high setting, even up to 100, can be used to improve the quality of
the audio material.
To minimize the depletion of the original sound in the Descratching procedure, you should
listen very carefully to the effects of the Declick and Decrackle parameters at various points of
the recording before deciding on their final values. In doing so, the Difference function in the
Playback area will certainly be a great aid. It allows you to set the parameters in a very intui-
tive manner. With it, you can switch between the original input signal and the input/output
signal difference, i.e. the portion that has been removed by the
Descratching algorithm. Nor-
mally, you do not want the signal difference to contain any part of the original signal that you
want to keep. For more notes on optimizing the settings of the
Declick and Decrackle parame-
ters, see to the Application Notes.
Note also that the Difference functions can be applied to the Descratcher and Denoiser func-
tions simultaneously. If you want to run the Descratcher only, leave the sliders ( threshold and
reduction ) for the Denoiser set to 0.