speed up 78 vinyl from 45rpm transfer!

[crizdee]

Hi,

I got to transfer and restore some old 78 vinyl recording! and my rec deck will only run at 45rpm so i will have to time stretch the recording back to their original speed and pitch. now my quick math tell me 73.5% pitch shift up will give me approx 78rpm fom a 45rpm. wow 73.5% is a big leap, is it going to sound awefull? anything i'm over looking to get better results!

I'll try melodyne and might try renting x-form for 2 days. the quality doesn't have to be amazing as the original recording are very noisy with loads of pops and crackles etc, but would like it to sound exceptible at least.

Chris

[tj_davies]

Can't you rent a record player that plays 78rpm? Or buy one? There's plenty at ebay.

73% time and pitch shift sounds a bit too much to me.


Timothy

[Mikey MTC]

It might be OK because you're not trying to change pitch and time independently. You just want to varispeed the recording. Didn't 78s need a special needle of a different width? A lot of it probably depends on whether you get enough out of the 78 disk in spite of the fact you're doing it at 45.

I'd be interested in how this turns out!

[Russ M.]

Since it was playing at 45 I would think you would have a problem with the EQ curve being skewed since all frequencies were shifted down then the crossover point will be in the wrong place etc.

[Carl Kolchak]

Hi Chris,

As was mentioned before, as far as I remember you had to flip a smaller needle into place for 78's (mine went to vinyl heaven many years ago, but there are some specialist music shops in Brighton that might be able to help - that classical shop in the lanes opposite that pastie shop springs to mind. I think they deal in audiophile stuff as well as classical cds but I may be wrong. I do have an old grammaphone with wooden needles knocking around somewhere but that doesn't really help you).

I don't think the RIAA curve is going to be much of a problem as it's really design to compensate for bass deflections, and seeing as you're pitching the record up, it would be out of its range though high frequency distortion might be a problem, but as you said - the quality doesn't have to be amazing, so suck it and see.

The one thing I think you should to is to record it at the highest sample rate your hardware is capable of say 192 kHz @ 24 bit, then Varispeed it down - not timestretch.
This will give you the best possible quality. You can then either bounce it out to the same sample rate / bit depth as your work session or just import it and let PT do the conversions on import.


Good luck and I hope that helps!

[Carl Kolchak]

Ooops!

Dumbass Disclaimer : re The RIAA curve, I mentally had the whole 78 - 45 vs 45 -78 speed thing Bass-Ackwards.

Yes, the 78 slowed down to 45 could be affected by the RIAA curve, but in all honesty I don't think it's going to be that big a deal and you could compensate with EQ for the purpose of making it sound natural.


Dhurr Brain

[crizdee]

Hi,

Thanks for all the tips guys and thanks to Hubert for this link..

http://www.a-reny.com/restauration/restaurcas.html

I did a quick test to see what i could expect, and this is what i did..

45rpm used varispeed on the deck to give me 49.5rpm then used time shift in varispeed mode to speed up by 57% (49.5 + 57% = approx 78) and the results were not too bad, considering this was a recording from 1958. i then used sonic no noise filters to clean as much as possible and tried the riaa filter but didn't seem to need it really? just hi pass and lo pass and a sharp parametric cut where most of the pop and crackle is. i also used sonic to de-crackle and reduce some noise which has helped, but these records are in a bad shape and are very dirty and very very noisy! i'll probably experiment a bit more and read the link that Hubert has send and see if i can improve it a bit, but i know it can be done to a reasonable degree.

Chris

[spinsong]

Ok I don't feel up to doing the math...but there is another solution slightly based on the article. this might seem a little odd but put the turntable on 33.3 (33.3 is almost half 78) and run it a little faster (the exact faster rpm speed you would have to do the math) so basically you would be running it lets say 90% speed divided by 2 which would be 45% speed.. record it at 96k then resave the file as 44.1 k... 96 x 45% = 43.2...like I said you would have to do the math to figure out how much to speed the turntable by, but the goal is to get it to equal 44.1...

result... better tracking on the vinyl side...because the record is running at a slower rpm (33.3 rpm needle doesnt bounce as much)

also no artifacts from using a pitch correction algorithm...basically its you doing the math (and it's straight math)

who would have thought that manual number crunching would help in recording...but they did tell you in school that one day it would help lol

I wanted to check if it would work and wound up doing the math... you would have to run it at 1.076 speed (35.83 rpm)

[Top Jimmy]

crizdee,

If you want to be exact, do the math, hack the header, and sample rate convert it instead of just getting close with % in a pitch shifter.

LOOK HERE

[Pepo]

I think if youre geting paid for it, you should rent a 78rpm player, even buy one. If you speed up in pro tools, you will be rising the pitch of the rumble to more audible frequencies.
Also, the needles are different. You still can get decent sound from a 45 rpm player, but not as good as a real 78.
When the records are broken and your restoration cds are the only thing left, they better be good.
Pepo