User Guide

Chapter 13: Tools and Utilities
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On many recordings, the extrapolated guesses are quite good. Frequent clicks can often be removed without audible
side-effects.
One might encounter a badly damaged record where the audio is so damaged that the guesses are not good enough
to be completely transparent.
In these problem cases, you could try setting Fill Gaps to 70, or 50, filling the gaps with lower-amplitude guesses,
which may sound less obnoxious.
Set Fill Gaps to 100, unless it sounds bad.
Smoothing
Some badly damaged records (particularly worn-out 45's and 78's) have high frequency noise approaching “crackle
on steroids.” The surface noise sounds like bacon frying. Crackle atop crackle, atop even more crackle.
The Smoothing section could be useful with severe surface noise. The Smoothing section is a very gentle Gaussian
low pass filter with 6 selectable intensities.
Gaussian low pass filters are “about as good as it gets” for attenuating random noise while having minimal effect on
music transients.
However, a Gaussian filter is still a low pass filter. All low pass filters reduce high frequencies along with surface
noise. You should only enable the Smoothing section if it is necessary for a badly damaged record. Experiment
with the Smoothing Level to find an acceptable tradeoff between reduction in surface noise versus reduction of
musical high frequencies.
DeNoise Checkbox
PG Vinyl Tool DeNoise is a “hiss gate.” It gradually attenuates quiet High Frequencies below the Denoise
Threshold. Think of it as a sliding high frequency dynamics expander.
Many vinyl discs were made from reel-to-reel tape masters. The best quality reel-to-reel tape recorders of
yesteryear had more hiss than modern digital recorders. A vinyl disc in excellent condition could contain an
accurate copy of the original tape hiss. In some cases, carefully adjusted DeNoise may give a perceived
improvement over the original noise level.
DeNoising may also be beneficial on low level disc surface noise (slightly worn discs). If you have low level
“frying bacon” surface noise, DeNoise might work better than Smoothing.
With loud “frying bacon” surface noise, you could try a judicious combination of Smoothing and DeNoise.
DeNoise Amount
This control sets the DeNoise threshold, in dB.
For instance, if you set it to -40 dB, high frequencies louder than -40 dB are passed unaltered. High frequencies
quieter than -46 dB are completely silenced. Levels between -40 and -46 dB are gradually faded down to complete
silence.
If the audio level at 8000 Hz happens to be below threshold, but the audio level at 4000 Hz happens to be above
threshold, the 8000 Hz signal would be muted but the 4000 Hz signal would pass un-altered. This is “Multi Band
Single-Ended Noise Reduction.”
The DeNoise section can slide the filter all the way down to 500 Hz; so on “silent” sections of a record, the DeNoise
silence can be pretty silent.
Carefully adjust the Denoise Amount so that desirable high frequencies in the music are minimally affected, but hiss
in the quiet sections of the music is removed. Even a 1 dB difference can be easy to hear when tweaking the
Denoise Amount. Many high fidelity vinyl records didn't have much information higher than 10 KHz (another
common mastering decision in the good old days). On many records, frequencies above 10 KHz can be squelched
most of the time without noticeably affecting the sound.
A suggestion for tweaking the DeNoise Amount; first increase the setting until the music is obviously losing high
frequencies. Then gradually reduce the level until the music is unaffected. This can ensure that any noise below the
minimum music level is exterminated. Be sure to check the DeNoise Amount against the quietest parts of the
recording, because the quiet locations are most likely to be affected if the DeNoise Amount has been set too high.
Conclusion
PG Vinyl Tool offers many tools which can clean vinyl records.