dbx 704X User Manual

Digital output card
Hide thumbs Also See for 704X:

Advertisement

Quick Links

Advertisement

Table of Contents
loading

Summary of Contents for dbx 704X

  • Page 2: Important Safety Instructions

    704X Important Safety Instructions The dbx 704X should only be used in a dbx 786, 160S, or a 160SL. Please follow the safety instructions contained in the man- ual for the product in which the dbx 704X is installed. ®...
  • Page 3 Notes ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________...
  • Page 4: Digital Output Card

    • Two user selectable noise shaping algorithms for lower perceived noise floor • Digital output on gold plated connectors • Can be installed in a dbx 160S/SL Compressor or a dbx 786 Precision Microphone Preamplifier Service Contact Information If you require technical support, contact dbx Customer Service.
  • Page 5: Warranty

    In all cases, you are responsible for transporta- tion charges to the factory. dbx will pay return shipping if the unit is still under warranty.
  • Page 6: Installation

    In no event shall dbx or its deal- ers be liable for special or consequential damages or from any delay in the performance of this warranty due to causes beyond their control.
  • Page 7 10. Insert the ribbon cable from the main board to the blue con- nector on the 704X. 11. Install the upper 704X PCB by lining up the two standoffs with the mounting holes on the upper PCB. 12. Install the last two screws into the standoffs holding the upper 704X PCB.
  • Page 8: Rear Panel

    SYNC IN and OUT Connectors: BNC connectors are provided for both sync in and out. The 704X uses low jitter phased-locked loops to synchronize to another unit’s wordclock output through the 704X’s SYNC in jack. The 704X will accept a 44.1, 48, 88.2, or 96 kHz wordclock input, or a 44.1 or 48kHz superclock...
  • Page 9 AES/EBU / S/PDIF Switch: Selects either AES/EBU format or S/PDIF digital output format. The LED will be red for AES/EBU and green for S/PDIF. TYPE IV Switch: Engages dbx’s proprietary Type IV™ analog to digital conversion system. See page 9 for more information on Type IV™.
  • Page 10: Sync Input

    (marked "Unterminated" on the circuit board) the 704X’s sync input. The same is true if you wish to use several 704Xs in a tapped configuration. The dbx 704X can also be...
  • Page 11 704X Daisy Chain Configuration Sync Source 704X Tapped Configuration Sync Source 704X 704X Digital Output Card ®...
  • Page 12 Type IV™ not only exploits the wide linear dynamic range of today’s A/D converters, but also enhances it and extends the useable dynamic range beyond the linear range.
  • Page 13 704X dB without the aid of noise reduction and around 75 to 85 dB with noise reduction such as dbx Type I™ or Type II™ applied. This seemingly tremendous signal-to-noise advantage of digital over analog would suggest that digital would become the unani- mous choice for recording.
  • Page 14 Type IV™ White Paper The obvious conclusion is that analog recording actually has more useable dynamic range than the specifications seem to indi- cate. For example, let’s say we’re recording a kick drum. If analog tape measures 55 dB from the 3% THD point down to the RMS...
  • Page 15 Enter the dbx Type IV™ Conversion System. Like its related predecessor technologies—Type I™, Type II™, and Type III™— dbx Type IV™ succeeds in preserving the wide dynamic range of the original analog signal within a limited dynamic range medium. Whereas Type I™ and Type II™ expand the dynamic range of ana- log tape and other limited dynamic range media, and the simulta- neous encode/decode process of Type III™...
  • Page 16 Type IV™ White Paper begins to be adequately represented in just 4 dB of the converter’s dynamic range, whereas a typical A/D converter would clip. With Type IV™, you can never clip the A/D converter! Converted Signal Level dB FS...
  • Page 17 This implies that half of the 704X Digital Output Card ®...
  • Page 18 As you can see, the low frequency signal simply gets dis- torted but maintains most of its signal characteristics, while sec- tions of the high-frequency signal are completely lost! With dbx Type IV™, its mapping preserves high-frequency signal informa- tion, as illustrated in Fig.
  • Page 19 Figure 3b - Signal of Fig. 3a Going Beyond the A/D Clip Level Amplitude High-Frequency Information Completely Lost High-Frequency Content A/D Clip Level Low-Frequency Content Time A/D Clip Level High-Frequency Information Completely Lost Figure 3c - Disproportionate Loss of High-Frequency Information Due to Clipping 704X Digital Output Card ®...
  • Page 20 Type IV™ processing, we reclaim the original A/D noise level! So what you get is free headroom! The benefits of the dbx Type IV™ Conversion System can eas- ily be heard by switching it in and out while listening to signals with high-level peaks captured in the Type IV™...
  • Page 21 A/D, you’ll realize that we never compromise your noise per- formance with Type IV™! The dbx Type IV™ Conversion System succeeds in combining the best of the analog and digital worlds to capture the truest essence and fullest dynamic range of audio signals. Who else but...
  • Page 22: Specifications

    Digital Output Card Specifications A-D Conversion: 24 bit, dbx Type IV™ Conversion System Converter Dynamic Range: 114 dB unweighted, 22 kHz bandwidth, Type IV™ engaged 117 dB "A" weighted, 22 kHz bandwidth, Type IV™ engaged Type IV™ Dynamic Range: Up to 127dB with transient material, A-...
  • Page 23 “S2.” Parameters: Input -60dBFS, 1 kHz; FFT Length= 2048, Sample Rate= 48 Khz, Averages= 32; Graph Steps= 1024. (a) 24-Bit word, (b) 16-Bit truncated output, no dither. Parameters: Input -60dBFS, 1 kHz; FFT Length= 2048, Sample Rate= 48 Khz, Averages= 32; Graph Steps= 1024. 704X Digital Output Card ®...
  • Page 24 8760 South Sandy Parkway Sandy, Utah 84070 Phone: (801) 568-7660 Fax (801) 568-7662 Int’l Fax: (801) 568-7583 Questions or comments? E-mail us at: customer@dbxpro.com or visit our World Wide Web home page at: www.dbxpro.com A Harman International Company Part No: 18-6315-B...

Table of Contents