45 degree LP stereo recording-B

 

Feb. 07 2010 under construction.

 

看看LP立體MM唱頭拾音的原理

看看LP立體MC唱頭拾音的原理






LP立體MC唱頭拾音的另一例：




特例：Denon MC唱頭 DL-103




看看源頭的LP立體刻片刀

http://www.sickoftalk.com/whyvinyl_two.html

Recording Discs
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Stereo Cutting Head

   
    The stereo cutting head consists of a stylus mechanically connected to two drive coils and two feedback coils, which are mounted in a permanent magnetic field, and stylus heating coil wrapped around the tip of the stylus (Fig. 12-10). When the signal is applied to the drive coils, the alternating current flowing through them creates a changing magnetic field, which alternately attracts and repels the permanent magnet.

Since the position of the permanent magnet is fixed, the coil moves in proportion to the strength of the field created and the attached stylus moves with it. The drive coils are so wound and mounted so that energizing either one alone causes the stylus to move in a plane 45 degrees to the left or right of vertical, depending on which coil is energized. Feeding both coils an in-phase signal causes the stylus to move in the lateral plane, while feeding the coils out-of-phase signals causes stylus motion in the vertical plane.
    The feedback coils are attached to the shank of the stylus and are, therefore, moved whenever the stylus moves. The motion of these coils in the permanent magnetic field creates a current flow in them, which is an accurate representation of the stylus motion. By mixing the outputs of these coils out of phase with the input signal in a technique called 「negative feedback」, several advantages are achieved.