As part of the maintenance of cassette drives, the entire drive mechanism is serviced. This includes, among other things, thorough cleaning, the replacement of vulnerable plastic parts and the treatment of certain components with application-specific grease or Oil. To ensure reliable function, the belts are replaced. The pressure rollers are carefully inspected and replaced if necessary. After maintenance, each drive is calibrated using high-quality test cassettes (level, tape speed and azimuth (optimal reproduction of high frequencies)) and operated in a longer test run. We can sometimes determine the quality of the sound head by the recording quality of a high-frequency sine tone. We use this data to decide, among other things, whether the device is still suitable for sale. The dev.
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