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笔者的一位朋友有一套健伍803CD组合音响,在播放CD片时音乐声中伴有噪杂的“沙沙”声,委托给本人维修并欲将它改装成VCD机。该音响的CD机型号为DP-49,经检查,判定为4倍抽样数字滤波器及16bit的D/A转换集成电路KAS01损坏。该电路集数字滤波D/A转换低通滤波及去加重等电路为一体的功能模块,各单元集成电路及外围元件全部焊接在一小块电路板上并在外表浇注一层黑色防护层,无法拆卸维修,且大部分器件较难购买到。好在这部分电路的功能可以通过VCD解压板上的同功能电路实现,于是决定置这部分电路于不顾,直接进行VCD机改装。
A friend of the author has a set of Kenwood 803CD combo audio. When playing CDs, the sound of music is mixed with noisy “rustle” sound, and it is entrusted to me to repair and convert it into a VCD player. The sound of the CD model for the DP-49, after examination, judged as 4 times the sampling digital filter and 16bit D / A converter IC KAS01 damage. The circuit consists of digital filtering D / A conversion low-pass filter and deemphasis circuit as one of the functional modules, the unit integrated circuits and peripheral components are all welded to a small circuit board and the appearance of a layer of black protective coating, can not Demolition and repair, and most of the devices more difficult to buy. Fortunately, the function of this part of the circuit can be achieved through the same function circuit on the VCD decompression board, so decided to set this part of the circuit regardless, directly for VCD machine modification.