I purchased this autoreverse cassette deck at a secondhand shop in London’s Notting Hill District for something like 40 quid. It looked hardly used but someone had removed the cassette load door. Happily my local HiFi shop managed to order one for me, and it fitted nicely.
The autoreverse feature of these decks are typically scorned at by some cassette users for having a detrimental effect to the sound. There are two possible choices for tape head configuration – either use a 4-track head and switch pairs in-use depending on the direction of the tape, or use a 2-track head and spin it around on a little platform to again match the tape direction. There is also the complication of driving the correct reels, providing twin capstan rollers, sensing tape type and overwrite protection, adding an erase head (or two!) and ultimately maintaining good speed stability and audio fidelity
I’m happy to say my SD-460 performs well in this respect, and is reliable to this day. This is even more remarkable given that the great Dutch Royal firm of Philips was in ownership of Marantz when this deck was built – and their traditional cost cutting which fails other Phillips products hasn’t taken it’s toll with this one 🙂