Subject:Restoring recording from acetate disk

Posted by: farss

Date:10/12/2004 7:02:26 AM

This recording is in reasonable shape given its age an where it originated although it does have some pretty bad plops and clicks in it along with a fair bit of scractchiness.
Are any of the tools such as click removal and vinyl restoration likely to be of much help with this or should I just leave well enough alone.
I'm concerned given the width of the plops that a setting broad enough to remove them will damage other things, perhaps 'drawing' them out is the safest bet?
Any advice from anyone whose been down this road much appreciated.

Bob.

Subject:RE: Restoring recording from acetate disk

Reply by: musicvid10

Date:10/12/2004 9:14:25 AM

Yep, done some of this by hand, very painstaking and time-consuming, but worth it if you have a rare archive.

Technique 1): Simplest and fastest -- reduce the pops and clicks by individually reducing their volume to below the level of the source material, don't eliminate them or you won't like the holes.

Technique 2): Silence the pops and clicks and paste in some audio from the waveforms immediately preceding the hole. A little blending can help here. Requires some musicianship.

After you've done surgery on the biggest errors you can use NR and some EQ to clean up the smaller stuff somewhat.

TIP: Always start and end your editing at zero-crossing points so as not to introduce more clicks.

Subject:RE: Restoring recording from acetate disk

Reply by: captn_spalding

Date:10/12/2004 10:13:19 AM

Here are the steps I reccomend:

1. Clean the disk in a very mild, barely warm, water - dish soap solution. Use a soft cotton cloth and wipe gently in a circular direction. Air dry. (I never play wet discs, though I know this is a common technique used by some restorers) You will be surprized by how much noise a good cleaning will eliminate.

2. If possible choose the proper stylus. You didn'tmention what the disc is, but since you said acetate I will guesssthat it some sort of transcription disc. A modern phono stylus will ride in the bottom of the gruve and give you un-acceptable results. A run of the mill "78 rpm" stylus will give you good results, but perhaps not the best. If your interested I can point you to articles on stylus configurations for various types of discs.

3. Playback equalization is also an issue. It most likely was not recorded with an RIAA equalization curve. Again there are online articles on the subject if ur interested.

4. Once the disc is in Sound Forge I would suggest the following steps.

5. Using the click and pop removal try various settings - start with the canned ones and adjust as your ear guides you.

6. After that highlight the clicks that are left and use the "fix small area" setting to remove the remaining glitches or, if need be, use the pencil tool to redraw the wave form

7. Now takea sample of the surface noise (in an otherwise quiet spot) and use NR to remove it from the entire recording. Again, play with the settings and let ur ear be ur guide. There is a standard setting that assumes the first 0.250 seconds of the recording is such a quiet area. You can start with that. Sufrace noise (quality and quantity) changes accross the disc, So i take a sample from the front for the first half and a sample from the end for the second half. Some times there are silent spots in between that I can use for intermdiate sections. It all depends on how much time you want to spend.

8. Finally use the tools that SF provides and sience becomes art as you play with the equalization, compression, etc. I personally go very lightly with this because I'm trying to preserve what is there and not add anything.

..spalding

Subject:RE: Restoring recording from acetate disk

Reply by: RiRo

Date:10/12/2004 1:07:15 PM

Having done this on several hundred records, this is by far the best step by step instructions I have seen online for this process. One "trick" I did is to borrow an old victrola and used a large capsule mic to get the audio into my digital recorder. I was shooting for the authentic sound of the record as it would have been played when it was first recorded, and was surprised at just how well the process did that.

Also, I repeat Spalding's record cleaning process... that single process can save days of processor time trying to fix noise. I have a label protector I use and have been known to soak records... It really makes a night and day difference.

RiRo

Subject:RE: Restoring recording from acetate disk

Reply by: farss

Date:10/12/2004 2:54:31 PM

I guess I should have explained in a bit more detail. The 'record' has already been copied to tape, just how good a job wasdone at that stage I can only guess. I'm hoping it was done by an archivist who knew what they were doing but quite possibly not, it doesn't sound like any effort was made to reduce the noise, but if they didn't know what they were doing that might be a good thing.

At one stage the tape was transferred to CD by someone who truly was clueless, there's serious clipping on the CD so I've had to go back to the tape, the actual acetate disk I have no idea where that is, possibly lost.

I'd like to thank everyone for their input, much appreciated. This project although only 12 minutes of audio is of a fairly significant work that forms a part of this countries history, it's the oldest surviving episode of a radio serial that ran for 27 years.

Very sadly only a few other episodes out of the nearly 6,000 have survived, as part of an economy measure the tapes were reused.

Bob.

Subject:RE: Restoring recording from acetate disk

Reply by: captn_spalding

Date:10/12/2004 4:41:49 PM

Nimbus records Prima Voce series transfers 78's to cd using an accoustic playback machine of their own invention. I've never had access to one good enough that I'd risk putting a valuable record on. Many of the Nimbus cd's are excellent. Particularly the pre 1926 records which were recorded accoustically and therefore flat. They do pretty much only vocal (opera) material. I think they stumble with later, electrical recordings that were not recorded flat. The voices still sound reasonable, but the orchestral accompnaments suffer.

...spalding

Subject:RE: Restoring recording from acetate disk

Reply by: plasmavideo

Date:10/15/2004 2:03:18 PM

Hey Bob,

Just out of curiosity, can you tell us which radio serial it was? One of my hobbies is collecting OTR (Old Time Radio) shows.

Thanks

Subject:RE: Restoring recording from acetate disk

Reply by: farss

Date:10/15/2004 10:49:57 PM

Blue Hills, ran for 27 years, i think 2,795 episodes, all but about 8 are lost but the scripts do survive. If ANYONE has any episdes many people including the National Archives would be most interested.

Bob.

Subject:RE: Restoring recording from acetate disk

Reply by: plasmavideo

Date:10/16/2004 4:29:43 AM

You might want to check with the group over at:

http://testbox.cob.rit.edu

There are a lot of folks in the user group who seem to have enormous collections of some often rather obscure things. I did a search for Blue Hills but nothing came back. There are forums there where you can post shows you are looking for. If I run across any in my travels I'll be sure to let you know.

Subject:RE: Restoring recording from acetate disk

Reply by: farss

Date:10/16/2004 6:30:34 PM

Thanks,
the ABC did include a request for anyone who held copies to come forward with the last release of the material.
Issue is the first 500 or so episodes were broadcast live to air so there was never a recording made and during the period after any form of audio recording device was so expensive that it's very unlikely anyone would have made off air recordings anyway.
Bob.