Banner
Banner
cookie-banner

Cartridge tests - Tracking

Article Index
Cartridge tests
Tracking
Separation
Output
Distortion
Vertical Tracking Angle
All Pages


mistracking

Mistracking, here of an Ortofon 2M Black on maximum 90µm peak amplitude track of CBS-STR112 test disc.


TRACKING


WHAT IT TELLS US

Tracking is the ability of the stylus to stay in contact with the groove on loud signals. If it fails to do so, then the sound becomes strained and eventually a regular short buzz can be heard as the stylus momentarily loses contact on music peaks, or mistracks. At worst the stylus can jump right out of the groove and the arm skate across the LP surface.


Not only does mistracking affect sound quality, it also causes groove damage. If subsequently played by a good cartridge that doesn’t mistrack the imprinted distortion sounds like mistracking.


The stylus assembly moves on a compliant hinge of rubber or springy tie-back wire, that latter providing better location. If the compliance of this hinge is insufficient the cartridge will mistrack large, low frequency excursions, like a loud bass drum.


The stylus has an effective tip mass too and if it is excessive the will not be able to accelerate fast enough to follow the groove at higher frequencies. This commonly produces mistracking on loud vocals having a strong sibilant content.


Budget cartridges have their stylus mounted on a small pedestal called a rondel. This allows it to clear detritus on the disc surface. But it also adds to tip mass and degrades high frequency tracking. A small diamond without a rondel (nude) is common on quality cartridges but fluff can gather under the stylus and cause mistracking.


HOW WE MEASURE IT

We measure tracking at 300Hz with CBS STR-112 test disc and at 1kHz with Bruel & Kjaer 2010 test disc. Both channels are fed to an oscilloscope via a special measurement preamplifier without RIAA. The distortion harmonics generated by mistracking are not attenuated by the 75uS high frequency characteristic of RIAA equalisation, giving a clear picture of the onset of mistracking. Mistracking is obvious as a distortion of the waveform. Tracking force is set to the manufacturers recommended figure and bias set so that both channels mistrack simultaneously.


cbs-str-112-test-disc-

CBS STR-112 test disc yields meaningful results for distortion and tracking tests. We also use B&K 2010.




 

Search

Hi-Fi World, Powered by Joomla!; Hosted by Joomla Wired.