REVOX B77 MKII MK2 4-track Reel-to-Reel Recorder. 3 3/4″ – 7 1/2″ ips. With Original NAB hubs and manual. Description: This is a new, unused Revox B77 4-track MKII machine. Professionally packed with styrofoam cushions and a cardboard box. We are reel-to-reel professionals and provide. We are proffesional suppliers of Reel-to-Reel equipment, reels and services.