Audio-Technica AT-OC9 phono cartridge Measurements

Sidebar 2: Measurements:

Measurements were made with the spot frequency bands on the new CBS STR-330 test disc, backed up by the older CBS STR-100. The latter generally showed a greater high-end rise than the former in the frequency-response readings, and the results presented in the reviews are those given by the more recent recording. Test-record results provide useful information, but they are not an absolute. Test records from different sources invariably give slightly different results. STR-100 was used to assess crosstalk, and trackability was measured at 300Hz using the Audio-Technica AT 6605 (MI 1261) test record.

The OC9 measured very flat—within ±1.0dB from 20Hz to 2kHz, –1.6dB at 6.3kHz, rising to +0.1dB at 12.5kHz, then dropping to –2.8dB at 20kHz (right channel; the left was slightly flatter, but not significantly different—within 0.5dB up to 16kHz). Crosstalk from left to right was down 24dB from 50Hz to 5kHz (even better from right to left—down 37dB at 1kHz). Trackability at 1.5 grams was fine up to 80um, and came close to tracking 90um. Subjective tracking on program material was fine, with little to choose from between the Audio-Technica and the other cartridges I review this month.—Thomas J. Norton