Nagra QSLS is a synchronizer for Nagra IV-S. Because of the doubling of some audio boards on the IV-S, in comparison with Nagra 4.2, Nagra could not integrate the equivalent of the QSLI into this tape recorder. The same playback control function by FM pilot locking from internal quartz is provided from the external QSLS box. One must not forget, when using it, to screw on the QSLS the crystal jumper plug in whose place QSLS connector has been connected; if not so, sync control is inoperative! The needle modulometer, on "Slave" position, shows correction carried out by sync control between read pilot signal and internal quartz.
Nagra QSLS, QSLS