Cleaning up 78 transfers Options

[tinpanalley]

Hi all,
I'm taking a 78 recording (and several others that I'm transferring) and trying to clean it up. I'm capturing the audio with Audacity at 32-bit IEEE float, as a stereo recording from a 78 stylus on my turntable at 45 then changing the speed, finishing it off with inverting the RIAA curve.
My question is about cleaning up from this point forward understanding of course that one method simply won't work in every case.

I have Audacity, Sound Forge, DeNoise and ClickRepair. I've tried following this to a certain degree but I have no way of knowing if there's something I'm missing, if it's out of date, if there's a better way, etc. Mastering, I'm ok with. It's just the cleaning part I want to know with the aim of archiving these transfers.

Any thoughts?

[tinpanalley]

Am I crazy to think that when I invert the RIAA curve the sound gets worse? The surface noise becomes far more prominent. I would imagine however that underneath that noise, the music itself is also having certain elements amplified and elevated but it's harder to tell under the amplified noise (A bit like trying to bring up the levels on a digital picture and battling with not blowing out the pixels to the point where you can see them?)
In any event, all other editing of the sound will clearly have to be done by my own ear but it IS safe to assume that ANY 78 needs the RIAA curve inverted right?

[Porcus]

Am I crazy to think that when I invert the RIAA curve the sound gets worse? The surface noise becomes far more prominent.

Well the EQ applied to the signal before the master (and which you have to apply to cancel the EQ applied in your phono stage), tilts the frequency response. Less bass, more treble. That's part of the idea; the bass in the vinyl should be down at a level where it wouldn't bounce the needle out of the groove, and treble should be amplified (still in the vinyl) to raise above the surface noise. If your old recordings did not have much treble, then what you are amplifying is main part noise, not much music.

In any event, all other editing of the sound will clearly have to be done by my own ear but it IS safe to assume that ANY 78 needs the RIAA curve inverted right?

They were recorded with other EQ curves -- at least, after electric amplification was introduced. You should apply the inverse RIAA curve to compensate for what your phono stage does, and then you should apply the masterhouse-specific curve to equalize what that record company did before pressing. You might as well implement the difference (correct curve minus RIAA curve) -- one per record. Whether applying the RIAA inversion only, is better or worse than zero -- I have no idea at all!
http://en.wikipedia.org/wiki/RIAA_equalization#History leads you to
http://www.bl.uk/reshelp/findhelprestype/s...restoration.pdf . Not even the “78” was universal!

This post has been edited by Porcus: Mar 5 2012, 03:13