This quadraphonic reel to reel stereo tape (discrete 7 1/2 IPS) was issued in 1973 on Atco Records (ATCQ 7029-QR) in USA. This special edition of Extension Of A Man has a different mix made by Joel Dorn including some lines of strings and the cover is slightly different too. This tape is quite rare today and it's usually sold around $200. You could also find the version on LP & 8-track.
