The AT-CAP4 is a versatile, two-sided turntable setup disc that enables you to adjust cartridge overhang, set cartridge offset and null points, and calibrate the platter speed.
The cartridge alignment side of the disc includes an overhang adjustment section that allows you to set the proper distance between the stylus tip and the turntable spindle (10–20 mm, according to your turntable’s specs). This adjustment is essential for ensuring proper tracking and minimizing distortion across the record’s surface.
The cartridge alignment side of the disc also includes null points for four different alignment geometries – Baerwald, Stevenson, Löfgren B, and UNI-DIN – providing optimal tracking and minimal distortion according to your tonearm’s effective length and your playback preferences:
- Baerwald (222–250 mm effective tonearm length): For listeners who play a wide range of genres and want a versatile alignment that minimizes distortion throughout the record.
- Stevenson (200–230 mm effective tonearm length): For classical, jazz, or any music with critical content closer to the label, where distortion is more likely.
- Löfgren B (222–250 mm effective tonearm length): For listeners who prioritize superior sound quality across most of the record’s surface, while accepting a bit more distortion near the inner grooves.
- UNI-DIN (220–240 mm effective tonearm length): For listeners who prioritize modern music, such as pop or rock, where critical content often lies in the mid-to-inner grooves.
The stroboscope side of the disc enables you to calibrate turntable platter speeds of 33-1/3, 45, and 78 RPM at 50 or 60 Hz. The stroboscope requires an incandescent or strobe light (not included) to view the strobe pattern accurately.
