I am transferring music from LPs. Some quite old and the level from the source is low. I would like to generally increase the input level as the recordings are made or increase the volume when editing. Input is from a quality turntable through a preamp (no adjustments available). Any help would be appreciated.
Audacity doesn’t do any processing during recording. Audacity has already scanned your file and the [u]Amplify Effect[/u] and it will default to whatever gain is needed for normalized (“maximized”) 0dB peaks.
Usually it’s best to amplify the whole album at once (or at least one side) so you can maintain the original relative loudness between songs.
Digital recording levels are not critical but if you need more than about 12dB of gain to hit 0dB that could be an indication of some kind of problem.
Note that normalized/maximized vinyl is usually not as “loud” as modern digital “loudness war” recordings. Older recordings were usually not as dynamically compressed. Plus, the vinyl cutting & playback process tends to increase the peak-to-average ratio (without affecting the sound of the dynamics).
Just a word of advice; you may need to change the bit depth you are capturing at depending on how high input levels you are achiving digitally. If you are peaking around -6 to -4 dB FS digitally 16 bit would be acceptable, but if you are peaking below that I suggest you use a bit depth of 24/32 bit, then convert with dither to 16bit when you have finished processing (cuts, fades, amplify, etc)
Just a word of advice; you may need to change the bit depth you are capturing at depending on how high input levels you are achiving digitally.
That might be “nice” but you can’t really do that… You get whatever bit depth your ADC/soundcard gives you. (And then by default Audacity converts temporarily/internally to 32-bit floating point.)
If you are peaking around -6 to -4 dB FS digitally 16 bit would be acceptable, but if you are peaking below that I suggest you use a bit depth of 24/32 bit,[/quote]It’s not THAT critical. At -12dB you are still using 14-bits which is good enough for vinyl (and almost anything else analog). Analog noise is usually the biggest resolution-limiting factor. (There are technical reasons for “processing” in floating-point.)
As long as your settings is reasonable and you avoid clipping and there are no dropouts/glitches, the “digital side” has little or no effect on sound quality. (There are good technical reasons for “processing” in floating-point.)
There are very few 32-bit ADCs & DACs and from what I’ve read most 24-bit ADCs & DACs are only accurate to about 20-bits so 32-bits is useless (for recording or playback).
Sorry, but I think you are needlessly complicating this with jargon that the OP may or may not understand.
I have some ^^very^^ early 16 bit files I captured when I started digitising vinyl over 20 years ago, where the recording levels are way too low (I was frustrated by clipping and wanted to avoid at all costs). They sound awful when digitally amplified becasue there is just not enough detail.
The OP mentioned that low levels were an issue for him, so depending on the levels we have given he should if possible capture at 24 bit, which he almost certainly has access to with reasonably new hardware. I don’t see how that should be controversial at all!
How low? 50% of the track height?
Unfortunately, when using WDM drivers, you will only get 16-bit even with 24-bit hardware.
WASAPI should give you 24-bit if (a) the hardware supports 24-bit, (b) the device is set to 24-bit in the Windows Sound control panel, (c) the sound card drivers fully support WASAPI.