Nem tudom ez ennek a fejkészlete, biztos? Az Akai azt a gyakorlatot alkalmazta hogy 2 db törlőfej volt beépítve. 1 db teljessávos törlő, 1 db 2x negyedsávos törlő, 1 db lejátszó, 1 db felvevő. Így lehetett normál sztereó felvételt is csinálni. A 2CH/4CH kapcsoló aktíválta a törlőfejet.

The GX-270D-SS (ca. 1976) and the GX-630D-SS (ca. 1976)

The GX-270D-SS and the GX-630D-SS were Akai's last Quad sets. The GX-270D-SS is derived from the GX-270D and has the auto-reverse capability in 4-track 2-channel mode only. Both sets have the Quadra Sync feature which means they could be used as a mini home- studio to a certain extent. Each channel can be switched seperately. They have a switch for either 4 channel or 2 channel use.

Since the GX-270D-SS has four heads, there's no fifth head for reverse play. The playback head is a four channel example and is used for both forward and reverse play in 2 channel mode. The other heads are: a full track erase head, a 4-track 2-channel erase head, and a 4- track 4-channel recording head. To adapt an earlier recorded tone pitch, the GX-270D-SS and the GX-630D-SS were supplied with a 5% pitch control function.

The more common 2- channel models (GX-270D and GX-630D/DB/D-PRO) didn't have that feature.

There are four microphone inputs and two headphone outputs available. The functions found on the GX-270D-SS are almost identical to those on the GX-630D-SS. Latter lacks the auto-reverse feature but can handle reels up to 10.5".