The current series of Clearaudio linear tonearms are NOT Souther design anymore. They are copied from the Opus3 Cantus tonearm using two rollers inside a glass tube so there's no need for bearings for the vertical movement. It's a simpler design than the Souther. The Clearaudio version seems to be higher mass than the original Cantus or maybe the ball bearings stick or dirty tube causing the lack of smoothness in horizontal movement.
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