RESTORING A TWO TON BAKER RECORD, or
Riding a Broken Bicycle

Oh, how I envy collectors of 78s by Enrico Caruso, Jelly Roll Morton, or Benny Goodman. Those records probably were originally bought by adults who treasured them and handled them with care; even if they've been bought and sold many times, they've been cared for. In fact, I have a copy of the very first jazz recording (Victor 18255, recorded February 25, 1917, by the Original Dixieland Jass Band), that looks absolutely pristine and plays perfectly. Alas, this is never the case with Two Ton records--I've yet to see one that hasn't been through the mill.

"The Bicycle Song" (Mercury 5368, recorded in 1950) is typical (and the pure "kiddie" records are often even worse).

screen shot of raw dub

Step 1
The first step is dubbing the 78 from my turntable into my computer. I use an audio editing program called CoolEditPro (since bought by Adobe and now marketed as Adobe Audition) for recording and editing, but there are many similar programs, even freeware ones, available for this purpose. The audio editor displays the song graphically (left; click on image for larger version), so you can "see" the noise as you hear it. This graphic shows a 13-second segment of the raw dub. Give it a listen.

screen shot of washed disc

Step 2
The first easy, and obvious, correction is simply washing the disc in soap and water--I use Ivory dish soap in warm water. Sometimes this has very little effect; in this case, the difference was dramatic: Listen.

The differences on the graphic display won't be particularly obvious; I've continued to include them for decoration more than anything else. You can see, though, that the huge thump at 3 seconds disappeared after cleaning.

screen shot of washed & declicked disc

Step 3
The first digital editing step is to run CEPro's auto-declicker against the file. This routine analyzes the song looking for very short, sharp sound spikes that are unlikely to be music but rather more likely to be a click on the record. For relatively clean LPs, this routine can work wonders, removing 90% of the audible clicks. For something as noisy as this 78, though, the difference is negligible: Listen.

screen shot of washed, declicked & NR50 disc

Step 4
The next step is noise reduction using a noise sample. For this part of the demonstration, I've taken the first few seconds of the song, including 1.5 seconds of the "silent" groove noise before the music starts. I marked off a second of that 1.5 seconds of noisy quietness, let CEPro sample and analyze it, then had CEPro remove that particular kind of noise all the way through the song. The effect is dramatic in this audio sample, which presents the before and after versions of that initial 8.5 seconds. The visual display is just as obvious.

This kind of noise sampling is rarely needed for relatively clean program material, such as a well-cared-for LP, but when (a) there's a recurring noise throughout the program and (b) you can find a "clean" area in which to sample that noise without any music covering it, it can be a godsend.

screen shot of washed, auto-declicked, NR50, manual cleanup, EQ, & adjusted levels disc

Step 5
Lest anybody think that this is all automatically done by computer: Guess again. For all the good that the foregoing steps have done, there's no substitute for listening to the song extremely carefully and watching the display sample at the same time. When you hear a noise, you must track it down and correct it. I usually have to study--visually and aurally--a sample as small as 50 milliseconds (50/1000s of a second) to find a noise that the ear hears as a brief click. It can easily take several hours to clean up a song that runs less than three minutes.

Two more steps have been folded into this sample: (a) Before the manual declicking, I apply a slight high-boost ("brightening") equalization on the recording to counteract the EQ that was typically built into 78 rpm records (called the RIAA curve); older preamps that were designed to play back 78s had this restorative EQ curve built into their electronics. Applying this EQ before, rather than after, manual declicking brings up little ticks that might have gone unnoticed before the brightening EQ. And (b) since taking out all the noise has typically reduced the overall level of the song, I reamplify it back to normal levels. Click here for the final version of the sample used in steps 1-3 above (shown in the graphic at left), and here to listen to the entire song.


Back to Main Music Page