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1、Page 1 of 3 Technical Bulletin L53 Product: DVD Receiver Hardware Technical Bulletin: L53-H2005-01 Date: June 27/05 Subject: SRS Distortion Note: Previous T.B.s required: K K K K YES K K K K NO DESCRIPTION: In SRS mode when playing certain CDs and some DVDS distortion can be heard coming from the sp
2、eakers. REASON: The input level to the SRS decoder chip is to high. SOLUTION: In figure 1 the red circle is the part of the circuit to change. R383 and R384 are 470 ohms. By lowering these resistor values , distortion in SRS mode will be corrected. Start by removing the top cover and locate the Audi
3、o pc board.This is the upper pc board mount behind the dvd mechanism. On the component side of the Audio board locate surface mount chip resistors R381 and R382. Check that their value is 1k ohm each. See figure 1 and figure 2. On the Audio board disconnect the tuner module flex cable CN22(see figur
4、e 3.) Main board flex cable (CN24), SPDIF harness (CN33) , and connector board (BN25/26). Remove the 6 screws from the back panel securing the Audio board. The resistors that require lowering are R383 and R384 , 470 ohms each. The addition of another 470 ohm resistor in parallel with each resistor w
5、ill give an overall resistance of 235 ohms each. To do this lift the board and turn over to access the foil side . Mount the two resistors (470 ohm 1/6w) from the negative side of C234 and C236. to ground at pin-1 on BN23. See figure 4 . NOTE: To enjoy SRS on this player we recommend that SRS mode i
6、s used with source material that is surround encoded. Certain stereo material will give unpredictable results. Contact: NAD Electronics International 633 Granite Court Pickering, ON Canada L1K 3K1 Voice: 905-831-0799 FAX 905-837-6357 RadioFans.CN 收音机爱 好者资料库 Page 2 of 3 Technical Bulletin L53 Product
7、: DVD Receiver Hardware Technical Bulletin: L53-H2005-01 Figure 1 (schematic of Audio board) Figure 2 R381,R382,R383,R384 SRS Decoder chip PC Board top view showing R381-R384 on Audio board. RadioFans.CN 收音机爱 好者资料库 Page 3 of 3 Technical Bulletin L53 Product: DVD Receiver Hardware Technical Bulletin: L53-H2005-01 Figure 3 Figure 4 Bottom of Audio board showing addition of 470 ohm resistors Audio PC Board RadioFans.CN 收音机爱 好者资料库