Editing Cassette deck (section)

==== Auto reverse for automated sequential playback of both cassette sides ====
In later years, an ''auto-reverse'' feature appeared that allowed the deck to play (and, in some decks, record) on both sides of the cassette without the operator having to manually remove, flip, and re-insert the cassette. 
Most auto-reverse machines use a four-channel head (similar to those on multitrack recorders), with only two channels connected to the electronics at one time, one pair for each direction. 
Auto-reverse decks employ a capstan and pinch roller for each side. 
Since these use the same opening in the cassette shell normally used for the erase head, 
such decks must fit the erase head (or two, one for each direction) into the center opening in the shell along with the record/play head.

In later auto-reverse machines, the ''auto reverse'' mechanism uses an ordinary two-track, quarter-width head, 
but operates by mechanically rotating the head 180 degrees so that the two head gaps access the other tracks of the tape. 
There is usually an azimuth adjustment screw for each position. 
Nevertheless, due to the repeated movement, the alignment (in particular, the azimuth) deviates with usage. 
Even in a machine with a four-channel head, slight asymmetries in the cassette shell make it difficult to align the 
head perfectly for both directions. {{Citation needed|date=March 2012}}

[[File:Nakamichi RX-505 autoreverse cassette deck.jpg|thumb|Nakamichi RX series RX-505 deck]]
[[File:Nakamichi RX 505 Top Open1.jpg|thumb|RX-505 auto reverse mechanism]]

In one machine, the Dragon, Nakamichi addressed the issue with a motor-driven automatic head alignment mechanism. 
This proved effective but very expensive. 
Later Nakamichi auto-reverse models, the RX series, was essentially a single-directional deck, 
but with an added mechanism that physically removed the cassette from the transport, flipped it over, and re-inserted it. 
Akai made a similar machine but with the mechanism and cassette laid out horizontally instead of upright.
This permitted the convenience of auto-reverse with little compromise in record or playback quality.{{Citation needed|date=March 2012}}