Over the last couple of weeks there have been several Akai, Teac, and Sansui quadraphonic tape machines for sale in Christchurch on Trade Me. A collection was being sold off. I bid on a couple of them but didn't get one as the price went too high. I didn't think they would go for much but they did prove to be popular. I'm not sure why as they are not as cool or well-speced as the 2 track machines. The quad machines date from the early to mid 70s, with the later ones having the Simul-Sync (synchro-record) feature. This was added when the manufactures realised that quadraphonic was not likely to take off. Eventually the whole idea of quad was dropped so the channels were renamed 1-4 (instead of FL,FR,RL,RR) and the musicians 4 track reel-reel recorder was born. I used to have one; a Sony 788-4.