Replace magnet with a mono play head?

[ppppenguin]

My view is that if you want a high quality cassette recorder, then don't use one with permanent magnet erase in the first place. if the designers intended it to be hgh quality they would have fitted a proper erase head. AFAIK, the main penalty for PM erase is excess hiss. Example of older discussion: https://www.tapeheads.net/showthread.php?t=17934 I suspect a PM will struggle to erase high coercivity tapes such as metal. Not a direct comparison but I've failed to erase high coercivity video tape of 1970s vintage using a older bulk eraser** that wasn't designed for the job.

I keep a couple of high quality cassette decks (Tandberg TCD310) around for transcribing cassettes. Probbaly got some old walkman style players lurking in a cupboard. Otherwise I don't use the medium.

If you're interested in cassette as a medium and want to use it for recording at better than dictaphone quality then use a decent deck. This could include the Sony Walkmans with record capability though I think these now sell at excessive prices. If you want to make high quality recordings then it's a lot easier to use a digital recorder. Anything from a smartphone to a Zoom H4.

**Reminds me that I have an oldish bulk eraser here that was intended for Umatic and similar video cassettes. It's coming to the B&B stall at Harpenden next month.