There are several issues that can affect turntable performance. The most common reasons for not obtaining optimal sound reproduction are:-

incorrect playing weight (either too light or too heavy) vertical tracking alignment (VTA) misaligned cartridge mismatched bias setting inaccurate platter speed

Cartridge alignment and speed accuracy have a critical effect on the coveted perfect sound quality that audiophiles strive to achieve. The "Once" Calibration Disc addresses these two signicant factors and, because it is a precision measuring tool, the listener's absolute satisfaction is ensured.

High Technology Stuff:
The "Once" Calibration Disc is printed on Yupo Phase 3 - a totally synthetic three-ply material. It is made from an amazing polypropylene film that exhibits the following characteristics:-

virtually untearable not affected by climate changes - will not shrink or expand impervious to moisture high resistance to creasing

The outstanding properties of Yupo Phase 3 ensure that the "Once" Calibration Disc will always remain a perfect circle with the spindle hole precisely in the centre.

Easy To Use Instructions - Cartridge Alignment

Fit your cartridge to the headshell, without fully tightening the mounting screws (to allow for movement). Place the "Once" Calibration Disc on the centre spindle Perform the overhang measurement and adjust if necessary Carefully rotate the cartridge so that it sits parallel with the alignment gauge lines. Do this by viewing from the front and also checking the azimuth by viewing from above Repeat steps 3 & 4 to establish a precise alignment Tighten the cartridge mounting screws Periodically re-check the alignment

Turntable Speed Check

Place the "Once" Calibration Disc on the centre spindle (see note) Start the turntable on the desired speed and allow sufficient time for the motor and bearings to warm up Direct a suitable 50Hz/60Hz mains powered fluorescent light source onto the surface of the stroboscope The stroboscope ring associated with your speed setting and mains frequency should now appear stationary

Note: To achieve the most accurate results, the turntable speed should be checked or adjusted while the stylus is in contact with a playing record.