For your father, you should still be able to find a new Denon DCD-900NE for about US$ 500.
This player is as good as it gets when reading CDs (FFT of a 1 kHz@0 dBFS tone taken at analogue output at 2.2 V RMS):
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Moreover, it has an USB port to read files on key (MP3, PCM up to 24bits/192ksps in FLAC, WAV, AIFF, ALAC and DSD up to 128FS), which is convenient.