公开(公告)号：WO1992022140A1

公开(公告)日：1992-12-10

申请号：PCT/US1992004751

申请日：1992-05-28

Applicant: VIMAK CORPORATION

Inventor： VIMAK CORPORATION ,  KOULOPOULOS, Michael, A. ,  SIGGELKOE, Russel, A. ,  HEGG, Thomas, R.

IPC: H03M01/66

CPC classification number: H03M3/392 ,  H03M3/51

Abstract: A digital-to-analog converter-preamplifier apparatus (100) serving as an interface between a source of digital audio signal data (101) and an amplifier is disclosed. A digital stage (102) receives multiple digital audio signal inputs, a selected one of which is analyzed by a digital audio interface receiver (214), processed by a digital signal processing device (224) and a delta-sigma modulator (225) prior to passing to the analog stage for conversion from the digital domain into left and right channel analog audio output signals. Volume control is performed on the audio signal in both the digital domain and the analog domain in order to optimize performance and minimize noise. The present invention automatically adjusts for input word lenghts of greater than 18-bits.

公开(公告)号：WO1994028543A1

公开(公告)日：1994-12-08

申请号：PCT/US1994006212

申请日：1994-06-02

Applicant: VIMAK CORPORATION

Inventor： VIMAK CORPORATION ,  KOULOPOULOS, Michael, A. ,  JAIN, Praduman ,  JAYASIMHA, Sriram

IPC: G11B05/09

CPC classification number: G11B20/1876

Abstract: An improved method for correcting errors in a sequence of digital audio data for use in a system having a compact disc player device and a digital signal processor. A compact disc player device reads a compact disc and outputs digital audio data as a series of digitized samples and detects erroneous samples. An error correction apparatus implements a finite impulse response filter (10). The method achieves a low level of interpolation error within the corrected output of the finite impulse response filter (10) by assigning zero-valued filter coefficients (H1 21 - Hn 24) to digital audio samples that are likely to be erroneous due to their proximity to a known erroneous digital audio sample.

Abstract translation: 一种改进的用于在具有光盘播放器设备和数字信号处理器的系统中使用的数字音频数据序列中的错误的方法。 光盘播放器装置读取光盘并将数字音频数据作为一系列数字化样本输出，并检测错误的样本。 纠错装置实现有限脉冲响应滤波器（10）。 该方法通过将零值滤波器系数（H1-21-Hn24）分配给由于它们的接近可能是错误的数字音频样本而在有限脉冲响应滤波器（10）的校正输出内实现低水平的内插误差 到已知的错误的数字音频样本。

公开(公告)号：WO1995009481A1

公开(公告)日：1995-04-06

申请号：PCT/US1994011026

申请日：1994-09-29

Applicant: VIMAK CORPORATION

Inventor： VIMAK CORPORATION ,  JAIN, Praduman ,  PEARSON, Carl

IPC: H03G03/10

CPC classification number: H03G1/00 ,  G01R31/2825

Abstract: An amplifier calibration apparatus (100) for use in an audio device including a manual volume control (130). An amplifier (101) which may include a digital potentiometer serves to alter the gain of the audio signal in response to a control signal. The amplifier calibration apparatus (100) includes a controller (102), a waveform generator (103) and a comparator circuit (104). The generated waveform is fed into the amplifier (101) and the resulting output is fed into the comparator circuit (104) and compared with a constant signal. The output of the comparator circuit (104) is fed to the controller (102) so that the controller (102) can calibrate the full scale point of the amplifier (101).

Abstract translation: 一种用于包括手动音量控制（130）的音频装置的放大器校准装置（100）。 可以包括数字电位器的放大器（101）用于响应于控制信号改变音频信号的增益。 放大器校准装置（100）包括控制器（102），波形发生器（103）和比较器电路（104）。 所产生的波形被馈送到放大器（101）中，并将所得到的输出馈送到比较器电路（104）中，并与恒定信号进行比较。 比较器电路（104）的输出被馈送到控制器（102），使得控制器（102）可以校准放大器（101）的满刻度点。

公开(公告)号：WO1993024926A1

公开(公告)日：1993-12-09

申请号：PCT/US1993004988

申请日：1993-05-26

Applicant: VIMAK CORPORATION

Inventor： VIMAK CORPORATION ,  KOULOPOULOS, Michael, A. ,  RAPPEL, Ronald, P. ,  HEGG, Thomas, R.

IPC: G11B17/22

CPC classification number: G11B20/10527 ,  G11B19/02 ,  G11B20/24 ,  G11B27/105 ,  G11B27/34 ,  G11B2220/2545

Abstract: An improved CD transport apparatus (100) wherein said apparatus incorporates a digital signal processor for processing digital audio signals read from a compact disc. The digital signal processor additionally serves to alter the gain of the digital audio signal when various control operations are commanded by the user so as to minimize audibility of extraneous noises which accompany such control operations and the potential damage which may be caused to audio components. The improved CD transport apparatus (100) further includes a cueing switch for causing movement of the CD pickup only during movement of the cueing switch and a shuttle switch for causing movement of the CD pickup only when the shuttle switch is in an active position.