Processing vinyl disks recordings using Audacity questions

Would like an advise from experienced users

I’m currently in the process of saving my old (1970-1980) vinyl disk collection (mainly classical music, vinyls are, as a whole, in good health) using Audacity recording via a USB-LINE connection on an Audio Technica LP120-USB player. I carefully remove dust and clean the vinyl disks with a record cleaner before making the recording. Due to some remaining clicks and some “hum” in very quiet parts as well as volume differences between different recordings (I mean on different disks), I’m presently doing the following on Signed 32 bit PCM recordings

  1. First make a noise reduction with the following parameters (-12 dB, sensitivity: 6.00, frequency smoothing: 0) taking as noise profile the silent part of the beginning of the recording (always a bit noisy); I noted that noise was always a bit less thereafter in transition parts, but I still use the beginning. May be I’m wrong about that.
  2. Then declick the record using the ClickRepair software of Brian Davies with the following settings DeClick:20, Pitch protection and Reverse On, wavelet technique
  3. Then amplify the full recording (Audacity effect) to -2 dB
  4. Finally save the record as WAV signed 16 bit PCM

I’m not an expert audiophile and couldn’t identify easily some possible loss resulting from this procedure.
My questions at this time are:

  1. I’m unsure about the order of the operations I performed for obtaining the best result. Especially should I amplify before performing noise reduction and/or declick or not?
  2. I noticed that after making the amplification step, some noise was back (seems normal) even if it was first removed but I don’t know if a 2nd noise reduction could be helpful without altering the quality of the recording
  3. Are my noise reduction settings OK or not

I tried to use the more conservative declick settings as reported on forums discussing Brian Davies software. Seems it is OK for me but any additional comment will also be appreciated

Hervé

I never bothered with noise reduction (or its predecessor Noise Reduction) when I made all my vinyl transfers.

Like you, I found Brian Davie’s default settings a little harsh, but I didn’t tweak down as much as you - I settled on 30 rather than 20, and I did this after extensive careful listening tests on high-end kit.

This workflow in the Manual is one that I put together in the Manual after I made most of my vinyl transfers (aided by several other experienced folk): http://manual.audacityteam.org/o/man/sample_workflow_for_lp_digitization.html

Before I started I gave my deck a good home service and replaced the cartridge (I kind of had to do that as I tried cleaning the stylus with a fine paintbrush and alcohol which dissolved the glue and removed the diamond tip - a new stylus and cantilever was going to cost almost as much as a new cart).

The trouble with noise reduction is that it always removes some signal too so it’s always a trade-off. Remember that if you play the LP through your hi-fi and turn the amp up you will get noise and vinyl roar (it’s all part of the famous “vinyl warmth” that the vinyl-purists rave about).

-2db Is a good final level to amplify/normalize to - -6dB is a good level to record at (the recording meter goes yellow at about that level).

My other tip is to work first on recordings that you care least about as your technique will improve. I started with my favourites and found myself going back to re-do them.

WC

Oh and perhaps the most important step in that workflow is #21 Backup: http://manual.audacityteam.org/o/man/sample_workflow_for_lp_digitization.html#backup

WC

You are already doing way more post-processing than I do in digitizing my own collection.

Like waxcylinder I find that the noise-reduction tool tends to do more harm than good, and never use it.

I do use Brian Davie’s program, but only on particularly bad recordings, for most I just leave the clicks and pops. With that program you do need to monitor the removed noise (or at least spot check it) to make sure it is noise and not the crisp edge on every high-hat cymbal hit.

I also don’t use Audacity, but rather a program called “wave repair” ( so named because it does have some tools for fixing bad pops and clicks) as I find it has a much more efficient workflow when it comes to dicing up the LP into tracks.

My standard post-processing is a 10Hz High-pass filter and then normalize to 0dB. I haven’t seen any reason to normalize to a lower value like -1 or -2dB as the peaks on LPs are always quite rare events anyway.

Now if some clever person could write a plugin to deal fix the frequency modulation (aka “wow”) caused by an off-center spindle hole:

http://www.flynwill.com/Misc/offcenter.wmv