An Introduction to the Restoration of Old Vinyl Records at Home

Ultrasonic Cleaner

The weakest point of the chain of recording is the sound source. A good sound source can save you from tedious jobs of editing. Vinyl records are full of pops and clicks due to dust and dirt. Cleaning is very tedious and sometimes very futile. After lots of investigation through the internet, I finally made the right decision and bought an ultrasonic cleaner for the vinyl cleaning. Ultrasounds of 40MHz causes explosive bubbles in hot water in 30-40 deg-C. These bubbles help cleaning out the hard-to-reach dirts from the groove lines. Because the vinyl can be wrap after hot bathing for some time, the water temperature should be kept below 40 deg-C. Thanks to this technology, a medium dirty vinyl record can be cleaned in 5 minutes with very good result.

A small ultrasonic cleaner with heat bath.  This model is more than enough for washing eyewear glasses. Water temperature can be adjusted up to 60 deg-C. The device attached by suction cups on the right side of the wall is an aquarium water filter. I add this because I am too lazy to change water frequently. The water should be as pure as possible. Distilled water is preferred but in order to reduce cost, I use RO water (reverse osmosis) which is virtually free when you have already installed one for filtering dirt for drinking water. This ultrasonic cleaner alone is 350USD in Taiwan (Distributor's price is 295USD) which is about the price of a vinyl cleaner on market. However, if you investigate carefully before buying, you would make the same decision like me.

This is seen when the water is cold.

This is seen when the water is warmed up. When the aquarium water filter is started, the water starts rippling and indirectly aids the formation of more vacuum bubbles. These bubbles explode themselves with micro-shock waves to break off the dirts attached on the grooves which is hard to be reached even when you try with strong detergent. 

The more the heat you apply, the more vacuum bubbles appear. However, please take care not to over-heat for too long so as to deform the vinyl.

A birdeye's  view to the vinyl cleaning. See the bubbles on the vinyl and the rippling water surface.

Five minutes is alright for me to clean an LP. I would let it dry on my self-made record holding device if I don't play it immediately or place the LP vertically elsewhere for drip-drying. Sometimes, I use soft clothe to wipe it dry at once for immediate use.

An Introduction to the Restoration of Old Vinyl Records at Home

Sound Editing with the best software - Cool Edit Pro

Bit Depth & Sampling Rate

Cool Edit Pro is the best sound editing software I've known so far. Just like photo editing, we need something to restore the original sound or add something extra in order to bring out the best result. The first step is to have the analog sound input put through the sound card to make it digitalized. Digitalizing an analog signal is known as the analog-to-digital conversion (ADC). To make it back to the analog sound is known as  digital-to-analog conversion (DAC). Digital medium for photo editing or sound editing, all need a conversion scheme. The higher the resolution scheme, the closer to the original, although  a low resolution scheme may catch the essential body of the picture but is incomplete with some lost fragments. The advantages of digitalization is the immaculate reproducibility and power of virtually unlimited rendering the original signals. In sound editing, we are dealing with 2 things basically. The bit depth which reflects the dynamic range and the sampling rate which represent the spectrum of frequency.

The Bit Depth The 24bit for DVD Audio is better than the 16bit CD Audio by the ability to reproduce sound in much more contrasting volume from very low whisper to loud screaming without distortion. Just like a 24bit picture looks more vivid compared to the same picture with 16bit color depth. 

8bit color depth picture

44.1kHz sampling rate includes a narrow spectrum of frequency up to 20kHz, but enough to satisfy the human ear (just like the TV screen)

96kHz sampling rate presents a wider spectrum more than enough to fill our ears (just like the movie screen)

Although it reproduces a wider spectrum of frequency, it still has its limit.

The Sampling Rate The sampling rate of 96kHz for DVD Audio  lets us reproduce sound from very low frequency from 4Hz up to >100kHz,  more than the human ear can detect. The CD sampling rate is 44.1kHz which safely represents the frequency range within the human ear limit, any treble more than 20kHz is cut abruptly(just like a TV screen shown above). The point is, what is the use to include side views you won't be able to concentrate clearly? Some scientist argued that the unheard high or low  frequency sound actually contribute to the finally feel of the sound through other sense organs all over our body other than the human ears. In order to reproduce the "true sound" the DVD Audio digitalization scheme includes a wider spectrum that is more than our needs for hearing. So it is obvious the 96kHz/24bit wins over the 44.1kHz/16bit format of recording...but just how much does it win? It's not ony the frequency spectrum has widened, the sound becomes more realistic just like seeing through a window with fine hairlines rather than the window-blinds.

After some listening experiments I've done with vinyl recording, I concluded that the DVD Audio is superior to reproduce with no obvious difference to the original analog. The CD Audio when you listen to side by side with the original or the DVD Audio (an A-B test), appears to be a little bit harsh over the highs.  The choice is obvious for quality. But for the time being the Performance-to-cost ratio skews to the CD format when you can digitalize the vinyl with the CDR so cheap today. My protocol is to digitalize the original sound source with higher resolution and store them in .wav format. After elimination of the background noise, the .wav files are down-converted to the CD resolution,  ready for the CD Audio transfer.

An Introduction to the Restoration of Old Vinyl Records at Home

Sound Editing with the best software - Cool Edit Pro

Recording

Recording through the analog input needs some basic setting which is not to be discussed here because there are too many different kinds of sound cards on the market. Anyway, after proper setting of the input level and selection of recording source through Cool Edit Pro, we now begin to record things.

Choose Settings to begin our basic recording settings.

A good Sound Card can record up to 24bit resolution, choose "Send 24-bit Using 3-byte Packed Format".

Choose the appropriate Sound Card for input and output. You may check "Adjust for DC on Record" if needed (see below). As you can see, this Sound Card is a cheap one. It does not support 24bit recording.

In order to monitor the signal input, you may choose "Show Levels on Play and Record"

To begin recording, click on "File/New... (Ctrl+N)". Choose the Sample Rate and Bit Rate. Choose 32bit- (float) for 24bit recording.

Now this Sound Card is recording the blank no-signal source after clicking on the red recording button on the lower left corner. Two red lines appear to show the sound level. Because there is no sound source signal. The 2 red lines represent the background noise incurred by the sound card itself. The upper (Left Channel)red lines shows a higher background noise than the lower (Right Channel) red line. The lower red line is at about -57dB with no input signal. The double lines on the upper part of the graph (Left Channel) shows that the Left Channel has a negative direct current (DC) bias. Therefore you may check "Adjust for DC on Record" box on the recording source (Devices) menu to eliminate the unwanted DC bias during recording sessions. However, you may also eliminate the DC bias later at sound editing.

I sent some signal input for testing purpose. You can see that the negative DC bias caused a small down shift of the left channel. 

To let you see clearly the background noise, you may click on "View/Spectral View" so that the low level bass hum can be seen clearly represented by the purple-colored mottling background. The background noise is quite annoying. In this case, you can see that this particular Sound Card has a background noise level of -57dB which means you can have a dynamic range of volume between -57dB and 0dB...a narrow range but still enough for ordinary home recording. CardDeluxe (399USD) is deemed the best Sound Card affordable for home recording. It's background noise is about -96dB in my hardware settings (The manufacturer's specification says that it has a signal-to-noise ration >100dB).

Now click on "save" to save the file .wav format (There are many different formats you can choose among).

You may specify the bit depth by clicking on the "Options.." button. However, for this cheap on-board Sound Card, the bit depth is limited to 16bit only. Now that you have saved the sound file in Untitled.wav or AnyNameYouWant.wav, we are going to do some editing.

NEXT PAGE: How to do the sound editing (4. Editing - Background Noise Elimination)

An Introduction to the Restoration of Old Vinyl Records at Home

Sound Editing with the best software - Cool Edit Pro

Background Noise eliminating

We are going to eliminate the background noise with Cool Edit Pro for the previously saved "Untitled.wav".

First you have to highlight a small part of the background area. Now select "Transform/Noise Reduction/Noise Reduction..."

Click on "Get Profile from Selection" so that the background noise is sampled according to the particular settings as shown (You can click on "Help" button to see what do these settings mean). After a while, the background noise is sampled and shown as red-yellow-green signals.

Click on the slide-bar of the "Noise Reduction Level" to drag along horizontally. You'll see the yellow lines going up and down between the red and green lines. If you slide up to the right, the sampled background noise will be removed completely (You can also choose to "Keep Only Noise"). If you click on the "OK" button, the highlighted area will be wiped out of the background noise.

See. The background noise is eliminated over the previously highlighted area, suggested by the removal of the DC bias.

To view it clearly, you may choose "View/Spectal view". 

To eliminate the entire file from the background noise, now select the entire file and repeat the noise reduction again.

Sometimes, the background noise you sampled is not exactly what it seems. You may need to re-sample on the right again.

This background noise sampled on the right is somewhat different from the previous one. In order to do the job completely for the entire file, click on "Close" instead of "OK" to quit the Noise Reduction Menu temporarily and then select the entire file. Now select the "Transform/Noise Reduction/Noise Reduction..." again and click "OK" to complete the job. This time I chose 100% Noise Reduction Level to simplify the job.

It's magic! But wait! You should listen to the sound before saving. When you choose to slide up the yellow line of the Noise Reduction Level, high level of background noise is eliminated. However, at the same time you take risk of adding artifact to the sound. What I do usually is to choose a value of 10% or below for the Noise Reduction Level and repeat the procedure anew by choosing carefully the background area again. A good noise reduction with no harm to the recorded signal may need more than ten times of careful Noise Reduction Procedure with each time renewing the sampling area. Tedious, right? But rewarding!

NEXT PAGE: How to do the sound editing (5. Editing - Prelude to Clicks & Pops)

An Introduction to the Restoration of Old Vinyl Records at Home

Sound Editing with the best software - Cool Edit Pro

Removal of Clicks and Pops - Prepare for Batch Job

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Before I go to the topic. I would like to go one step further to exemplify the idea of dealing batch job. Many times we face some easy but repetitive jobs, we would like to do it in a batch rather than individually one at a time. Removing clicks and pops could be a batch job while removing background noise is much complicated. I would like to show you with the project beginning with the .cda files processing. Here is a CD Mr.R.Beetison sent me. This is a clean and clear vinyl recording, divided track by track which were already burned into CDR with 24 .cda tracks files. We need to turn the CD tracks into .wav files in order to edit the sound files.

Place the CD into a CDROM, activate Easy CDDA Extractor for extrating the CD Audio files .cda into the computer. The program shows that this CD has 24 tracks. Because this is a home-made CD, we cannot find any data for the tracks, and no ready reference could be retrieved from the CDDB online. For proper reference of individual tracks, we would like to type in the names of the songs...but I thought that would cost me some time even though I can type fast and accurately. So, I searched the web to see if I can directly use the web resource to replace tedious hand typing. After a few keystrokes for the basic infos to fill the blanks of Artist, Genre and Album, I quit the program. To quit the program is an important step because it writes the CD data to the reference data file called cdplayer.ini in the windows folder.

Now go to the windows folder and edit the cdplayer.ini file by any text editor. I use UltraEdit for text editing because it has many convenient  features. 

At the end of the Cdplayer.ini file you can see that Easy CDDA Extractor has written some data including what I've typed in the fields of Artist, Title(Album) and Category(Genre) but the song titles remain blank. We are going to fill in the title-blanks.

Now search the web for the album data. You could find one on Lyn Paul Website.

See! I found this. Copy the Data we needed for the tracks to a text file and rename it NSLive.txt (Any name you like).

Do some editor's job to make it tidy.

In order to make the track titles to fit the cdplayer.ini format, we need to do some tricks to add the 0=, 1=....23= at the beginning of each lines.

Select Column Mode first. Microsoft words won't give you this convenience to edit text with column mode.

Highlight the beginning of each line by selecting the initial part of lines.

Select Insert/Fill Columns.

Fill in the blank with "=".

So, this action has placed the "=" at the beginning of each line.

Now repeating the procedure but select the "Insert Number function" this time. Begin with "0", with increment "1", we'll get the following result.

However, the job is incomplete. We have to delete the "0" at the 10-digit place in order to make it fit to the Cdplayer.ini format.

Hightlight and delete.

OK, it's done. Quit Column Mode. Highlight the completed text and copy them to the clipboard.

Open the Cdplayer.ini to highlight the to-be-replaced text and copy from the clipboard to replace the blank data.

Now it's all done. Save and quit the text editor.

Activate the Easy CDDA Extractor again and you'll be happy to see the song titles already fit to the appropriate tracks.

Extract the .cda files to the computer to the folder you want. You can choose to make .wav or mp3 etc. For sound editing, we choose the windows .wav format.

WOW, tedious enough? Now get the Clicks & Pops eliminated in a batch...Next!

NEXT PAGE: How to do the sound editing (6. Editing - Clicks & Pops Batch preparation)

An Introduction to the Restoration of Old Vinyl Records at Home

Sound Editing with the best software - Cool Edit Pro

Clicks & Pops Eliminating in a Batch

To remove the clicks & pops of the vinyl recording. You can choose the internal plug-in of Cool Edit Pro. However, an external plug-in developed by Jeferry Klein called ClickFix is much faster and equally effective for removal of the annoying clicks & pops.

Before we do the clicks & pops removal, we want to record down the process once for reference and register it in a .scp (script) file.

Select "Open/New Collection".

Give the New Collection a name, for example "ClicksPops.scp".

Give it a Title, I typed in "Clicks & Pops". Now press the Record Button and begin the procedure.

Our aim is to repeat the job over and over for different .wav files. The procedure includes the following 2 steps.

1.Select Entire Wav.

2.Activate the ClickFix plug-in and execute.

I select the "LP, good condition" because it adds the least among of artifact to the .wav file.

After pressed on the "OK Button", the job begins.

This is the result. Now close the summary.

We've got the clicks eliminated now. How nice. 

To end the recording of the 2-step procedure, activate again the "Script & Batch Processing" to save the .scp file.

Click on the "Stop Current Script" Button.

Now click on the "<<Add to Collection<<" Button.

You may press on the "Edit Script File" to find out what has been written for the recording of the whole procedure.

You may edit the non-essential part of the script, for example, replace the Collection Title with an appropriate one. It is interesting but most of the data recorded down are very low-level numeric values unknown to all of the users, so let's close the editor and save the .scp file and move on. Press on the "Close" Button to leave the script menu.

NEXT PAGE: How to do the sound editing (7. Clicks and Pops - Final Batch Processing)