Deutsche Version
EMT 930
EMT 930 is a turntable with an idler wheel. Built as the "smaller brother" of the legendary EMT 927 it is still a very demanded unit.
A chassis made of bakelite and coloured with "Hammerschlaglack" rests on a metal frame. A synchronous motor with three phases moves a heavy platter by means of an idler wheel. Upon the heavy platter rests a light weight auxiliary platter which can be stopped. When the brake is released the continuously rotating main platter runs the auxiliary platter very fast with the standard speed. The motor rotates synchronous with the mains frequency and was either built for 50c/s or 60c/s. Also the strobo light is locked with the mains frequency and shines through the holes in the auxiliary platter to indicate the speed. The speed can be fine tuned by means of a felt brake below the main platter. Also like the motor the auxiliary turntable must be used with mains frequency it was designed for. For using the 930 with another mains frequency please follow the link.
A direct coupled lift raises or loweres the tone arm. Until the tone arm EMT 929 was introduced the first units EMT 930 have been equipped with tone arms made by Ortofon.
The very first units had been pure mono units and have been equipped with the tube driven equalizer amplifier EMT 139 which was later replaced by a stereo version. Here and there the mono units are still available while the ETM 139st is a very rare unit. Attention: For using a tube unit the according supply voltages for tube and anode potential must be available.
The successor was the equalizer amplifier EMT 155 (available in mono and stereo) which in same cases was customized with 47kohms input for magnetic pick-up's. To simulate a current at the anode potential a resistor was built-in. The high voltage was not longer needed for the EMT 155, but in older EMT 930 it was used to drive the stroboscope lampe.
Only the equalizer amplifier EMT 153 did not longer offer the possibility to switch to several equalization curves.
The bearing sleeve and the axle of the main platter are adopted to each other and can't be replaced as single unit. A good bearing will show about 180 seconds until the platter stays when used without felt fine tuning brake and started with 78 rpm. Replacing the oil depends first of all on using the machine. But also a unit which is only seldom switched on should be serviced after 3-4 years. As far as your unit is not equipped with the rather old bearing (without cover with thread) it is not too difficult to replace the oil and clean the bearing. Please take care that also the motor, the felt of the fine tuning brake and the felt of the idler are supplied with some oil. You can oder the appropriate oil in packages of 50ccm (will reach for about 2 fillings) and 500ccm.