• CD CHECK

This is the error correction test for digital recording playback that contains five audio tracks in combination with disk error patterns, and is used to test the players ability to read all the tracks without problems. As the player advances along the CD's surface (from track 1 to track 5), the errors become more and more difficult to correct.

The SONY DVP NS955V showed good performance by passing the first four tracks without any problems, but in the fifth track we heard audible clicks.

Check level 1 (track 1): Standard manufacturing errors

Check level 2 (track 2): 0.375mm scratch

Check level 3 (track 3): 0.750mm scratch

Check level 4 (track 2): 1.125mm scratch

Check level 5 (track 2): 1.500mm scratch

• Abex TCD - 726

This is an AudioCD disc used for measuring the error correction capabilities and adjustment of the tracking/focusing servo characteristics of a player against defects included on a typical CD. Three kinds of defects are included on this disc: interruption in information layer, black dots and fingerprints. The interruptions are fabricated by intentionally varying the lengths of pits on the disc fabrication area. Their size varies from 0.5mm to 1.0mm. The diameter of the black dots is sized from 0.4mm to 1.0mm. Lastly, the simulated fingerprints are small gathered dots, of diameters sized from 65 micrometers to 75 micrometers 160 black dots in total, construct the artificial fingerprint.

Again, the Sony device behaved extremely well passing the interruptions as well as the fingerprints and black dots without producing any audible clicks.

• Philips SBC 444A

The Philips SBC444A is similar to the previous disk, with interruptions on the information layer that vary from 400 micrometers to 1000 micrometers and black dots with a size of 300 micrometers to 800 micrometers.

As was expected, the SONY DVP NS955V also passed this test without difficulty.

• Abex TCD – 721R

Here we have the same contents as with the Abex TCD – 726, but with different defects. A scratch sized from 0,4mm to 3.0mm on the disks surface. The symptoms expected when playing this disk are noise, skipping, same sector repeatedly played, start of tune cannot be detected etc. This is a far more difficult and demanding test disk than the Abex TCD – 726.

The SONY DVP NS955V passed the first 12 tracks with no problems at all but the 13th and 14th tracks played with a couple of clicks. Amazingly it was able to also read the 15th track with just a few audible clicks, proving that in error correction, itis a really good device.