Hi. The Eurovox MCC 6701 was the stereo AM/stereo FM radio cassette with L/R balance control and the Eurovox MCC 6860 was the stereo AM/stereo FM radio cassette with joystick balance/fader control. The MRB 6201 was only AM/ stereo FM cassette. A lot of eurovox service manuals on this site
https://www.kevinchant.com/eurovox.html . Cheers MD