John_z, I believe you could test for yourself. Since your options for a Nak will mean buying used, bring your Walkman with you when auditioning any deck you're considering to purchase and ask for a tape the seller made from that deck. Listen to it on the deck for sale, then listen to it on the Walkman. That should tell you if there is a compatibility problem.
And speaking of used Naks, from my experience I could not recommend the 480. I think it was a budget deck and not up to the standards of their other products. The one I owned did not perform as well as the Aiwa 770 I replaced it with or the even better Pioneer CT-S800 I bought after that. The Pioneer was a good bargain as it offered virtually the same specs as the Pioneer Elite, except for the glossy faceplate and wood cap ends, for half the price.
And speaking of used Naks, from my experience I could not recommend the 480. I think it was a budget deck and not up to the standards of their other products. The one I owned did not perform as well as the Aiwa 770 I replaced it with or the even better Pioneer CT-S800 I bought after that. The Pioneer was a good bargain as it offered virtually the same specs as the Pioneer Elite, except for the glossy faceplate and wood cap ends, for half the price.