Consumer Electronics

MAGNETIC PICKUP HEADS

Magnetic pickup heads (moving-iron and moving-coil) have basically constant velocity characteristic, the output voltage being proportional to the velocity of vibration of the pickup stylus (measured at its equilibrium position). Output voltages which are quoted for comparing magnetic pickup heads should therefore be given with reference to stylus velocity. This reference can be made directly by quoting the velocity; alternatively the ratio (expressed in decibels) of the actual output voltage to that which would be obtained at some standard velocity (1 cm/s) should be given. Hence, an output voltage could be given as, say, 100 mV at 3.16 cm/s or 100 mV at +10 dB, and both expressions would be equivalent.

Moving-iron magnetic ...