Thanks to everyone’s advice on here. I just picked up the kx-330. Still waiting on speakers and I need to give it a good clean/service (hadn’t been used in ~3 years) to make sure everything is up to scratch.
To use separate speakers you will need an amplifier. Look locally. This one (currently at £25) is worthy of the Cool Stuff for Sale thread https://www.ebay.co.uk/itm/275408064364?hash=item401f998f6c:g:rWcAAOSwlARiwvKr&LH_All=1
Okay cool, thanks. I was looking into getting some sort of system that could connect to multiple devices in my room. I also got some surgical spirit, 95% industrial methylated spirit. Apparently it’s the same as rubbing/isopropyl alcohol (maybe even better?) so I am going to use it to clean the tape head. unfortunately my first tape has gotten really dirty already
Tapes will get gooey over the years and have "tape shred." It's much rarer with cassettes, I get it more with reel to reel tapes but it looks like black flakes or gooey blobs. If your seeing that after playing tapes, don't use them.
If they have an important recording on them you can bake them. That is what recording studios do. You will have to Google how to do it as it isn't something I have ever tried. Regarding amplifiers with lots of inputs this was the first Yamaha one that came up on eBay. https://www.ebay.co.uk/itm/363940253625?hash=item54bc878fb9:g:iisAAOSwIbJi88jA It probably cost about £500 new but is about as fashionable as a CRT TV these days.