To add to the above, since tape recordings (and erasing), use a high frequency signal anywhere in the region of 40 - 100 KHz, wondering if
an external hardware 20 KHz LPF connected in series with the players output, before going into the line-in of the sound card would have any
advantages?
Such as reducing possible aliasing and generally make the ADC’s life easier by removing any frequencies that are not need anyways.
The website link below, shows the freq response of some better known tape players/deck:
http://www.ant-audio.co.uk/Tape_Recording/Graphs/FR/album/index.html
The high end limit of tapes is lower than 20KHz, so the filter could start cutting off from around 16 KHz or so.
Maybe something like this:
(RL is the load impedance of the sound card input, normally around 10K ohm).
(The 3.3uF caps are DC blocking as some cheaper players/decks have a DC offset on the headphone
jack and when used as a feed for the sound card, this DC will cause problems).
