Need help restoring 78 rpm records

[cromag]

Craig Maier said:

... What do they call someone who can speak fluently in only one language? Answer: That person is an American.

Actually, most Americans I know don't even fit THAT category!

[Jan Myren]

78 rpm restoration help

Hi again, folks!

I really mean the high pass filter, freq. 55/18 db butterworth for rumble, yes, that's the preset called "Demo Audio DE-Rumble", the filter we used during the cleaning up on the demo. I think this works well in most occations.
I use this one after the impulse filter, just as described in the manual under "Restoring a 78", in depth.

I have tried to do a restoring job in two multifilter chains:
Chain1: Imp -> High pass (de-rumble) -> Median
(then I take a noise sample at the beginning of the records, without any music, and then I go over to the next multifilter chain: ->
Chain 2: CNF -> Low Pass (freq. 7700/ 24 db butterworth, it's the pre-set called "Steep 78 surface noise) -> DNF (spectral exiter enhancer). The last one filter I use to "brighten up" the sound, a hint I found in "Tips of the day".
Of course the use of this filter brings back much of the noise.

My main problem may be that I am not getting rid of enought clicks, pops and crackle BEFORE I go to the CNF, so that I fool this filter. I normally use the EZ Impulse and the settings 50 (sctratch) and 50 (crackle), just as mentioned on the demo-restoration job and the manual: "Restoring a 78", in depth.

I probaby should always run more impulsive noise removal than the EZ?
perhaps I should run the music file through more impulsive filters?
I have tried to run a chain consisting of EZ (50/50), Imp 1(9000/10/1 (78 mode), Imp 2 (1/13/60) (vinyl mode), Imp 3 (1/5/85 (HQ mode), Median (3 samples, O weight) and the High Pass (freq. 55/18 db butterworth for rumble).
All in one multifilter chain.


Another thing, I am a bit confused about the main settings on the CNF for attac, release and attenution when I take the noise sample. On the demo-restoration job, we use 125/250/35, and it sounds great on that purpose, but not on my own work. I usually use 50/115/10, settings I have found on the pre-set "General Purpose Filter" under the multifilter menu.

The average filter has never been used. Do you perhaps use this filter together in the same prosess as the median-filter?


Well, as you can see, I experiment quite much, but I always feel that I'm soon back where I started......

And; If anybody wish a trip to Norway, you'll all be very welcome! Here's pleny of music, and nice coffee as well!!

Hope to get even more response during my experiments on restoring old 78's!!

Best regards
Jan
NORWAY

[Craig Maier]

Hi Jan,

There is a step that concerns me in Chain 2:

CNF -> Low Pass (freq. 7700/ 24 db butterworth, it's the pre-set called "Steep 78 surface noise)

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Most 78's have some useful information above 7,700 Hz. That filter setting is designed for acoustical 78's mostly. And then to use 24 dB / Octave lets almost nothing above that frequency through.

I would suggest trying 10 or 11 KHz, 12 dB/Octave, Butterworth response instead unless you are working with acousticals.

That may be what is "dulling-up" your restorations.

[Jan Myren]

Restoring 78's - need help!

Hi!

Thanks again:

Dough, you wrote:
For distortions I use either the Punch 'n' Crunch filter or dynamic filters. Then, and only then, I run it through the CNF.
What settings do you use for the filters you mentioned??
Sharing experiments om MP3 sounds intesting. Thank you for your offer, I'll see....

And to you Craig, thank you, I'll check out your tips this evening....

Best regards
Jan NORWAY

[DougMac]

A little trick.

Hi Jan,

There is a step that concerns me in Chain 2:

CNF -> Low Pass (freq. 7700/ 24 db butterworth, it's the pre-set called "Steep 78 surface noise)

------------------------------------------

Most 78's have some useful information above 7,700 Hz. That filter setting is designed for acoustical 78's mostly. And then to use 24 dB / Octave lets almost nothing above that frequency through.

I would suggest trying 10 or 11 KHz, 12 dB/Octave, Butterworth response instead unless you are working with acousticals.

That may be what is "dulling-up" your restorations.

This post reminded me of a trick I'd forgotten about. If I decide to use a low pass filter on a 78 and I'm concerned about losing musical data, I first use the high pass filter (at the same db/octave slope) and and adjust upward until I no longer hear musical content. Based on the era and label this might vary significantly. Once I've established the lowest possible setting with no musical content, I close the high pass filter and use that setting for the low pass filter.

I'll also mention the pschoacoustical effect that has been mentioned in the past. You can take a recording and introduce a slight amount of high frequency noise and folks will describe the modified recording as being "brighter". It's hard to clean up the hiss in an old 78 and A/B it without thinking you've "lost" something. I find it helpful to file away the result for a while and come back and listen to the cleaned file without listening to the source. The "dull" file will end up sounding just fine.

I'll mention one last phenomenon I've noticed. I've recently restored some records that I had taped before I had restoration software or the ability to apply correct EQ. I remembered them sounding better except for the surface noise and I was concerned that I was introducing distortion in the restoration process. That led me to digging up the old tapes (mostly cassette) and listening to the copy I made many years ago. To my surprise, underneath all the scratches and crackle lay the very distortion that now seems more noticeable. It seems that by removing some imperfections, any remaining imperfections stand out that much more. I've also found that one of the most important steps in the restoration process is to start with a properly cleaned record.

Doug