Info On Old Disc

Discussion in 'Mastering' started by Derm, Aug 18, 2006.

  1. Derm

    Derm Guest

    I have just received an old disc for transcription. I reckon it could be 60 years old. It is made from metal and is coated in "vinyl". I only know its metal as the vinyl or whatever material it is, is scratched off in parts.
    Can I play this disc on a modern turntable without damaging it?
  2. Thomas W. Bethel

    Thomas W. Bethel Well-Known Member

    It is an acetate disk and it can be played on a modern turntable. The problem is that the acetate is starting to flake off and if you don't do something about it fairly soon the whole record will come off in pieces one piece at a time. It was cut on a lathe and was most probably for someone's reference or one off disk. There is a guy in Nashville USA that does beautiful work on re-gluing the acetate to the aluminum and if you need his address I can get it for you. We do a lot of restoration and this is a common problem with lots of older acetate disks that were not well taken care of and the environmental effects of poor storage are exactly what you are describing.

    Best of luck!
  3. JoeH

    JoeH Well-Known Member

    Don't play this record yourself without doing some homework for the proper the styli you need for the groove size and depth.
    You may want to look into different sized needles for this. No doubt this acetate is mono, and it might benefit from something larger (about 1 mil) than the standard LP stereo needle.

    Go here and do some research first:

    they say this about tips and styli:

    Most needles can come equipped with a variety of different tips. Metal, osmium, sapphire, and both man-made and natural (or nude) diamond comprise the list of various tip materials, listed in order of least to best quality. LP tips which play 16,33 and 45 rpm records will range from .5mil to 1.0mil in the conical variety, with .7mil being the most common. A 1.0mil tip is for mono recordings only! Whereas .5 to .8mil tips are for stereo records. The part number suffix is -D7 for a .7mil diamond tip, or -S1 would be a sapphire 1.0mil tip etc.

    An -S2 is a universal compromise tip for all speeds, not great for record longevity. A -D3 or -S3 is a diamond or sapphire 3.0mil tip which is a 'wide groove' tip designed only for 78rpm records. Those are the usually 10inch in diameter records made of acetate in the early 1900's before the advent of 'microgroove' vinyl LP records is another place to start looking for your cartridge.

    If the thing is severly damaged, you may even try some creative things like taking only ONE side of a stereo cartridge feed; sometimes one wall is damaged worse than the other. It can be tedious, but for good restoration work, sometimes ya gotta dig a little deeper.

    Good luck with it!
  4. RemyRAD

    RemyRAD Guest

    I just recently purchased a pair of 78 rpm stylus' from both Shure and Stanton for an archival project I am beginning. I WON'T be transferring the disks at 78 rpm, but rather at 45 rpm with a flat preamp, using custom deemphasis curves to taste within software, while also adjusting the speed.
    S l o w e r is better.

    See Jane hop. Hop, hop, hop.
    See Dick run. Run, run, run.
    Ms. Remy.........Ann??........David, yes, David, David, David?
  5. Derm

    Derm Guest

    Thank you all for the replies, I'm going to look at them all in depth.
    Do have an equation for speeding up the recording in software from 45 to 78? Can you elaborate more?
  6. RemyRAD

    RemyRAD Guest

    I use the "pitch bending" features in Adobe Addition. Because these historic old recordings which were all operatic, were recorded in the times before the industry had frequencies stabilized motors, no 78 rpm recording was actually at 78 rpm. That's right, they varied between 72 to 84 rpm on average! So in this archival project I'm beginning, I have to know what the intended key signature is of each particular piece of music was written for. Most of these recordings were done in the United States where A 440 was the basic standard for tuning. Thankfully I am also working with the soprano who has a very good sense of pitch memory. My largest concern is how consistently offspeed the recording may remain? So I will need to also utilize a reference pitch source to check periodically throughout the entire transfer.

    I am going to attempt to utilize a flat preamplifier as opposed to the more modern RIAA curve. The reason for that is the RIAA curve had not yet been invented. Other preemphasis and deemphasis curves were utilized that were similar to the later RIAA curve but not quite identical. this However, I will still require that the phonograph cartridge be loaded into a 47,000 ohm resistor along with an appropriate capacitor to ensure proper resonance loading of the cartridge for flattest response. Values that are already built into a phono preamplifier but without the deemphasis equalization circuit.

    The preamplifier I am going to use needs to have a considerably good low-end response, more so than the high frequency response since all of the frequencies will be cut in half when transferring. But since I know there are no usable frequencies below 100 hertz on any of these recordings, I only need a low frequency response of my preamplifier down to 50 hertz. The rest will be trial and error to obtain decent and pleasing results.

    After the transfer, I will need to add the approximate type of deemphasis equalization to produce a pleasing sounding end product with a software equalizer such as the FFT filter within Audition.

    I'm going to have to experiment as to whether it will be better to utilize the software noise reduction features to remove the surface noise, scratches and pops at the slow transfer speed or whether it will do a better job at the properly adjusted speed? Or whether a combination of both might yield the best results? And since I am utilizing both Shure and Stanton stereo cartridges and none of these recordings are in stereo, I will be able to utilize other techniques for best results. Some of these recordings may be lateral cuts, some may be vertical cuts? So any thing that I can do to restore these precious 60+-year-old recordings, I'll do.

    A careful cleaning of each disk will also be in order. Water and a light bit of dishwashing liquid is all that I shall utilize. I intend to use distilled or deionized water as tapwater can have microscopic particles of calcium that could do more harm than help.

    It seems like the old days? I'm going disk to disk!
    Ms. Remy Ann David
  7. BRH

    BRH Active Member

    Well, I've been doing the same type of work, but I playback at 78, or whatever is closest. I find out what key the music is in and use a chromatic tuner set by the speaker to adjust the speed, ... looking for strong tonics and fifths... (not to be confused with gin martinis..... but they do come into play) If I remember correctly, 60 years ago our pitch was below 440... possibly 435. We are just getting higher and higher (Sing...... "I wanna take you high-er"....)

    Don't play the record with a standard 331/3 cartridge, it will ruin it further.
    Like MS Remy said, do use distilled water to clean....No alcohol or acetone based cleaners please. Some people use 1 drop of dishwashing detergent or Kodak Fotoflow in the distilled water as a wetting agent.
    Consider a phono pre like the KAB Souvenier for correct (close to correct)
    playback. Uses passive eq playback...... more phase correct.

    Elberg make a good one too. Both are Class A electronics About $1400

    Then there's the Millennia..... $10,000! JEEZ

    I'm using a Stanton straight arm, plows right thru those deap scratches, but don't tell anyone about this. If the disk is a larger 14" or 16" you will need a special turntable.

    And then I'm using the Pencil Tool in ProTools, Waves Restoration and Z-Noise plugs. Pretty good luck with those if not hit too hard.
    But the purist are going to come right back with "Cedar De-Clicker is the best." You can rent one or buy it for $10,000 I think... That outa do it.
    I'm trying to specialize in restoration because there are a lot of really good recordings out there not on CD. And a good recording, is a good recording, is a good recording, no matter what the media!!!
  8. Derm

    Derm Guest

    Thanks all for the great info.
    BTW, what do you all use to physically wipe the discs when cleaning?
  9. Thomas W. Bethel

    Thomas W. Bethel Well-Known Member

    Distilled de ionized water ONLY no chemicals.
  10. Derm

    Derm Guest

    Thanks Thomas, but I was wondering what you would wipe with, a special cloth etc.
  11. Thomas W. Bethel

    Thomas W. Bethel Well-Known Member

    The problem with cleaning an Acetate record that is starting to flake is that you can do damage to it very easily. If it were me I would use one of those 3 M cloths that are sold in most major retailers here in the US. They are lint free and very soft. I would spritz some deionized distilled water on the cloth and very gently go around the record in a circular pattern being very careful not to push into any of the acetate that is starting to lift up. If the record was in better shape you could use a normal disk cleaner on it but it might be to harsh. We have also used mushroom brushes on 78 RPM records for deep cleaning the groves but we are careful not to push too hard.

    Hope this helps.

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