Ortofon SPU Classic N The SPU Classic N provides the same sound reproduction properties as the SPU Classic GM series, but is sold without the integrated headshell unit.  The SPU Classic N is a Moving Coil (MC) cartridge with an 18µm spherical stylus profile.  Listeners who wish to mount the SPU Classic on a traditional headshell may do so by using SPU N adaptor.Those with vintage SPU-type headshells* can use the Classic N to recreate an authentic and functional SPU cartridge.   *Vintage SPU-type headshells are no longer available. We offer Special Repair Service for  SPU Classic N » Technical data   Output voltage at 1000 Hz, 5cm/sec. 0.2 mV Channel balance at 1 kHz < 1 dB Channel separation at 1 kHz >20 dB Channel separation at 15 kHz >10 dB Frequency range at - 3dB 20-25.000 Hz Frequency response 20-20.000 Hz ± 3 dB Tracking ability at 315Hz at recommended tracking force *) 65 µm Compliance, dynamic, lateral 8 µm/mN Stylus type Nude spherical Stylus tip radius R 18 µm Tracking force range 3.0-5.0 g (30-50 mN) Tracking force, recommended 4.0 g (40 mN) Tracking angle 20° Internal impedance, DC resistance 6 Ohm Recommended load impedance >10 Ohm Coilwire material High Purity Copper (OFC) Cartridge colour Black Cartridge weight 13 g