Because it was never intended for general consumer sale, finding an original copy often requires searching specialized secondary markets:
: Occasional listings appear on AliExpress or eBay (though listings may often be for the similar YEDS-18 Type 4 ). sony test disc yeds7rar
: It is used for signal performance tests and optical readout tests. Because it was never intended for general consumer
: Ensuring the laser correctly follows the microscopic pits on the disc. sony test disc yeds7rar
: Measuring the voltage of signals at specific points in the circuit, such as a 1 kHz sine wave at 0 dB.
Test CD for laserdisc calibration, is it necessary? - LDDb Forum
: The YEDS-7 replaced the earlier Type 1 and Type 2 test discs, consolidating their functions into a single reference.