Yamaha YPC-1 Owner's Manual page 9

The VOLUME control features a precut brass
case, gold plated multi-contact brush, and low-
resistance, low-distortion carbon ink, which
together provide very smooth operation and an
L/R linkage error of ±1 dB or less.
The INPUT selector features a rotary switch
designed specifically for the YPC-1. The
contact resistance is less than 5mΩ, which
contributes to signal transmission with less
distortion.
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