I’ve written about this before.
That depends on which piece of audio equipment from the 1970s, is being compared with which piece of equipment from today.
If the equipment consists of a top-quality turntable from the late 1970s, compared to the most basic MP3-player from today, and if we assume for the moment that the type of sound file which is being played on the Portable Audio Player, is in fact an MP3 File recorded at a bit-rate of 128kbps, then the answer would be Yes. Top-quality turntables from the late 1970s were able to outperform that.
OTOH, If the audio equipment from today is a Digital Audio Player, that boasts 24-bit sound, that only happens to be able to play MP3 Files, but that is in fact playing a FLAC File, then it becomes very difficult for even the better audio equipment from the 1970s to match that.
Top-Quality Audio Equipment from the late 1970s, would have cost over $1000 for one component, without taking into account, how many dollars that would have been equivalent to today. The type of Digital Audio Player I described cost me C$ 140.- plus shipping, plus handling, in 2018.
Also, there is a major distinction, between any sort of equipment which is only meant to reproduce an Electronic signal, and equipment which is Electromechanical in nature, including speakers, headphones, phonographs… ‘The old Electromechanical technology’ was very good, except for the basic limitation, that they could not design good bass-reflex speakers, which require computers to design well. With no bass-reflex speakers, the older generations tended to listen to stereo on bigger, expensive speakers. But their sound was good, with even bass.