[78-L] Audacity and off-center transfers

Fri Mar 11 15:57:17 PST 2022

Yes, CEDAR is expensive.  When it came out it cost more than my house.  But times have changed and it's down to just a little more than my last two cars.

The question, as noted in the subject line, is whether anybody has mastered AUDACITY's ability to affect this same change. It will increase (and decrease) time and pitch, as I have learned fixing an acappella chorus that went 1/2 step flat, and saved a dragging cassette that took a 45 minute lesson and drug it out to 59 minutes.  Both sent to me from CDs made by somebody else.

The trick with AUDACITY, methinks, is to find a starting point, increase the next 0.3846153846153846 seconds (half a revolution of a 78, the swing out) by X%, then decrease for the same % for the same time (the swing in).  Repeat for 3 minutes.  The % of change, I'm guessing, is a function of how far off-center the 78 was as transferred.   I don't see that as impossible; difficult, to be sure, but not impossible.  To further define the problem, it appears to me that the arc of the needle swinging out and back are probably not linear rates, so there's probably a set of curves to go with it.  Somebody at CEDAR figured all that out and wrote a program for it, which, of course, added to the price.  AUDACITY has a lot of tips for 78 transfers in the manual, and I didn't find any helps there, but my copy is a few years old, so I had some hope that this may have been added.

I transferred a white label party record (pressing, not lacquer) a few years ago that was obviously a dub which was off-center.  I tried off-centering the copy I had to see if I could realign it.  I got close, but not 100%, so I centered it and hoped for a cheap digital solution in the future.  I'd forgotten all about that until now.

I put this question to Google, and the kids there decided that you cannot fix a sun-warped LP this way.  Duh.  Maybe they haven't tried CEDAR.

Rodger Holtin
78-L Member Since MCMXCVIII

For Best Results Use Victor Needles

-----Original Message-----
From: 78-l-bounces at klickitat.78online.com [mailto:78-l-bounces at klickitat.78online.com] On Behalf Of BURNHAM
Sent: Thursday, March 10, 2022 10:39 PM
To: 78-L Mail List <78-l at klickitat.78online.com>
Subject: Re: [78-L] Audacity and off-center transfers

CEDAR has a program that will do an impressive job of removing wow!  I put a 45 rpm disc on the turntable so that the inner edge of the large spindle hole was up against the small normal spindle so that the eccentricity of the rotating disc was wildly off and played it through the CEDAR program and the record played with no audible wow whatsoever!  The only drawback of this program is that it’s VERY expensive!!

Sent from my iPhone

> On Mar 10, 2022, at 19:44, Dustin Wittmann <dpwittmann at gmail.com.invalid> wrote:
> 
> 
> Definitely don't make off-center transfers to begin with. I use three 
> rubber mats on my new Technics SP-10R and can raise my tonearm high 
> enough (plus VTA adjustment) to manually center any record. Timestep 
> sells modified Technics tables, too, with truncated spindles for a 
> pretty reasonable price for serious archivists. There are also the 
> belt-driven Rek O Kut tables sold by Esoteric Sound. I have my trusty 
> Rondine 3 up on eBay now, for what it's worth.
> 
> I've never had any problems with records moving even without spindle 
> support. There's always a record clamp.
> 
> Remember, too, that if you digitize a record at slow speed, you need 
> to do it flat and then add EQ after re-pitching. If the EQ is present 
> before that, it will be in the wrong wrong place!
> 
> CEDAR Cambridge has a re-speed plugin that can re-pitch records based 
> on any number of observable factors in the spectrum, but you don't 
> want to rely on that...few can afford it. I just blew a lot of future 
> record budget on a system and plan to use it on many of the records 
> that suffer from inconsistent lathe speeds.
> 
> Dustin Wittmann
> 
>> On Thu, Mar 10, 2022, 6:21 PM Malcolm <malcolm at 78data.com.invalid> wrote:
>> 
>> 
>> I use a piece of 1/4" Styrofoam sheet cut to 12" diameter. Punch or 
>> cut or ream out a hole in the center just big enough to fit over your 
>> turntable spindle. Put the adapter on the table. The spindle should 
>> be hidden in the hole. Place an off-center (78rpm) record on the 
>> adapter with the center holes lining up  The friction between the 
>> styro and the record will be enough to hold the record stationary on 
>> the styro no matter what speed you're going to play it at. Run the 
>> table initially at
>> 33 or 45 and adjust the record by gently tapping along its edge until 
>> the groove no longer wanders and tracks straight. Then you can play 
>> the record at it's normal speed when digitizing.
>> I use a Technics SP-15 table and this trick works every time.
>> I've never lost a record due to it's being flung off the machine!
>> I don't think Audacity or Audition have an algorithm that allows the 
>> digital repair of an off-center disc. At least they didn't a few 
>> years back.
>> Malcolm R
>> 
>> *******
>> 
>>> On 3/10/2022 1:58 PM, Rodger J Holtin wrote:
>>> Just picked up a CD of Teddy Wilson Columbias (booklet missing, of
>> course)
>>> and the first track is off-center.  Rust shows that title as 
>>> unissued, so the source might be a one-only.  C'est la vie.
>>> 
>>> 
>>> 
>>> I've learned a lot of tricks with Audacity and I'm going to guess
>> there's a
>>> fix for regular pitch changes such as those wrought by off-center 
>>> 78s,
>> but I
>>> haven't figured it out yet.
>>> 
>>> 
>>> 
>>> Anybody else mastered that technique?
>>> 
>>> 
>>> 
>>> Rodger Holtin
>>> 
>>> 78-L Member Since MCMXCVIII
>>> 
>>> 
>>> 
>>> For Best Results Use Victor Needles
>>> 
>>> 
>>> 
>>> 
>>> 
>> 
>> _______________________________________________
>> 78-L mailing list
>> 78-L at klickitat.78online.com
>> http://klickitat.78online.com/mailman/listinfo/78-l
>> 
> _______________________________________________
> 78-L mailing list
> 78-L at klickitat.78online.com
> http://klickitat.78online.com/mailman/listinfo/78-l

_______________________________________________
78-L mailing list
78-L at klickitat.78online.com
http://klickitat.78online.com/mailman/listinfo/78-l

-- 
This email has been checked for viruses by AVG.
https://www.avg.com