The Deliverator – Wannabee

So open minded, my thoughts fell out…

Pop, Click and Hiss Removal

Posted by Deliverator on January 4th, 2007

This entry relates to this previous entry on the Ion USB Turntable.

Several people I have spoken to about converting record collections or who have read my previous entry have asked me about audio post processing/cleanup. Of course, the phrasing has generally been more along the lines of “so, can you really get rid of all those popping noises from scratched records?” The answer to this question is actually pretty complex. There are a lot of post-processing tools you can use to clean up a recording, but you have to be very careful in adjusting settings and listening to the results, as the same filters that can remove popping noises can also remove or mute particularly staccato instruments like certain drums. I generally found it best to go fairly light on the filter settings to remove the majority of pops and then manually edit the waveform to remove any particularly offensive remnants. This semi-automated cleaning produced excellent results without being overly burdensome on my time.

Another thing that I found helpful in reducing noise was to make sure the record was VERY clean before recording it. There is nothing you can do about scratches, but you can get rid of dust, fingerprints and other surface contaminants that WILL show up audibly in your recording. Vinyl records, due to being made of plastic, become statically charged and attract dust very easily. I used a highly evaporative cleaning spray designed for optical surfaces and a microfiber cloth to remove dust and oil. My procedure was to liberally spray the side I was about to record from and let the spray soak into and loosen any surface contaminants. I then spun the record on the turntable and formed a small wedge with the microfiber cloth and just barely let it brush the surface of the record. The microfiber cloth easily soaks up the fluid from the surface without further scratching the record. Any remaining fluid in the grooves quickly evaporates away after letting the record spin for a few minutes. I cleaned the cloth off in soaping water, rinsed it and then let it dry on a bit of mono filament after each used, to keep the cloth free of any dirt which could scratch the next record I attempted to clean. Water evaporates so very quickly from microfiber that I was able to use the same cloth record after record for hours on end.

Here are a few screen grabs of how much popping noise can be removed from a waveform without distorting the underlying music.

Before

Audio Before

After

Audio After