The actual cause of the problem is already in your thread title: "Record" and to an extend "Recording".
Just to make things very clear and short: FLAC is a bit-perfect copy of a PCM audio stream (or WAV as it is often called).To make it easier to understand are the differences between the terms
"recording" and
"ripping". A
recording is basically taking another device to capture an audio signal while the source medium plays along.
To do so, there are many "joints" in a chain which can be different:
*What is the LP/tape like?
*What is the turntable/tapedeck/reel-to-reel like?
*What cable is being used (I had a humming jack-to-jack cable once adding bass in the lower frequencies)?
*Is any sort of noise reduction turned on?
*Is there an equalizer running?
*Is there any gain used (e.g. MIC-IN or LINE-IN) during recording (check your soundcard / system properties) or in your DAW (the computer programm you use). Just one dB more and people perceive that as "better".
Contrary to
"ripping": To rip means that there is
NONE of these above problems involved as "ripping" means "extracting" the audio stream 1:1 the way it is, often within the system itself. No EQ is being applied, no cables can cause trouble and the quality of the stylus does not matter. The term stemmed from computer games where the music files have been "ripped" out of the files from the game, often via hacks. By doing so, you have no change of the actual signal, so "rips" are pristine and always the same as the source medium/source file. E.g. ripping a CD is done on your system from CD directly to the file.
That's it. Nothing else involved. So you can never "rip" a LP/tape/analogue medium to begin with. If you have a CD ripped and it suddenly has more bass, you should get an exorcist.
You have heard of a "CD ripper", you can "rip DVDs" and still "BluRay rips" are a thing. But never a "casette ripper" or "LP ripper", right? If so, I'd be surprised
So as you soon as you "record" something, differences are always happening. The PCM or FLACification at the end just works with the skills of the recording equipment and the guy/gal operating it.
Pretty recently, a bunch of SELECTED SOUND albums have been shared on this forum and I was flabbergasted how great these sounds. Yes, the LPs a private person owned sounded MUCH better and clearer than the WAVs you could get directly from APM. The guys over at APM, while
recording (either the master tapes or the LPs) probably added noise reduction or a low-pass filter or whatever. The sharer here, sorry if you read this and I forgot your name!, recorded it absolutely masterful and this made this user's shares an absolute upgrade.