Thanks to you both for your replies.
I have been testing and may have found some losses through digital format conversion.
Setting Sample Format to 32-bit float rather than 16-bit worked a lot better than before.
Then I tried a simple test. Whilst recording in Audacity, I pressed the Record button On and Off repeatedly.
I found the sound played back with the Record button On was really not as good as that with the Record button Off.
How do we explain this?
Perhaps on my system the playback of 32-bit float is not as good as that of 16-bit unsigned.
But still I think this indicates that the 32-bit float recording may not playback as well as the directly stored 16-bit input from USB.
This is a small loss which I would prefer to avoid.
Perhaps my Windows platform is at fault, but it is only four years old.
Are my Audacity settings still not the best? I list them below.
I want to store my 16-bit USB input as exactly as possible, split into labelled tracks as 16-bit WAV files.
I would prefer to avoid format conversion.
Is there any way I can do this with current Audacity?
Perhaps a later Audacity will allow us to choose a single format throughout.
Can you suggest a simple 16-bit editor to complete my simple task?
My Audacity Settings…
In Audacity > Edit > Preferences > Devices, I used settings…
Host: Windows WASAPI
Using: PortAudio 19.5.0-devel, revision unknown
Device: Speakers (Realtek High Definition Audio)
Device: Line (3- USB AUDIO CODEC)
Channels: 2 (Stereo)
Buffer length: 1000 mS
Track shift after record: -130 mS
In Audacity > Edit > Preferences > Quality, I used settings…
Default Sample Rate: 48 kHz
Default Sample Format: 32-bit float
Sample Rate Converter: Best Quality (slowest) – increased from Medium Quality (may I increase this on an unstressed 3.30 GHz PC?)
High-quality conversion: Best Quality (slowest)
Turntable: Reloop RP-2000 USB.
Computer: Asus MC51BC of 2013, 64-bit, Windows 10.