Look for the 682 with dolby B & C. The 680, 681, ZX7, 1000, and nearly all the Nakamichi Decks sound very very good. The 680 had a 1/2 speed selection. The 582 or the 500 series that had all the adjustments was a great deck which led to the 670 and 680 series of decks. The 580 sereis reign supreme for years until then. We use to use that with DBX or Dolby C or S and it reduced the noise tremendously. Also, I would make tapes for my car and I would change the setting for metal tape from 70us to 120us. That would give me an extension or boost on the top end. Used with Dolby it was an alternative to an equalizer. My cassette days have been behind me for over 24 years and I hope I remember correctly. Good Luck!
