The 704 outboard A/D converter uses dbx's patent-pending Type IV conversion system, with the equivalent performance of a 27-bit system. The 704 also features numerous word reduction and noise shaping options, and is the only product on the market to offer user-definable noise shaping. A choice of 8, 16, 20 or 24 bit output is offered, and outputs can be dithered and noise shaped using one of the many predefined curves or via user-defined settings.
- Sample rates at 44.1, 48, 88.2, and 96 kHz
- Wordlength output at 16, 20, or 24 bits
- Dither to 16, 20, or 24 bits using TPDF or SNR2 algorithms
- dbx Type IV™ A/D Conversion System
- Sync input/output using low jitter phase-locked loops
- 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
AES/EBU OUTPUT Connector
The 704X provides AES/EBU digital output format through the XLR connector. Be sure to use short lengths of 110Ω digital cables rather than standard XLR to XLR cables. Using the correct cables will prevent digital dropouts and other interconnect problems.
SYNC IN and OUT Connectors
BNC connectors are provided for both sync in and out. The 704X uses low jitter phased-locked loops to slave to another unit’s wordclock output through the 704X’s SYNC in jack. The 704X will accept a 44.1, 48, 88.2, or 96kHz wordclock input, or a 44.1 or 48kHz superclock (256X sample rate). You also may use the 704X as a master clock through the SYNC out BNC jack to supply stable clocks to other processors that accept a sync input. See "Sync Input" for further information.
The SYNC LED will light red when the 704X is locked to an external clock through the SYNC IN BNC jack. Note that one of the RATE LEDs will light to indicate the clock frequency of the external source.
S/PDIF OUTPUT Connector
The 704X provides S/PDIF digital output format through the RCA coaxial connector. Be sure to use short lengths of 75Ω digital cables or 75Ω video cables rather standard audio RCA to RCA cables. Using the correct cables will prevent digital dropouts and other interconnect problems.
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™.
Selects output sample rate of 44.1, 48, 88.2, or 96kHz. The upper LED will light red for 44.1kHz and green for 48kHz. The lower LED will light red for 88.2 kHz and green for 96kHz.
Selects noise-shaping curve of SHAPE 1, SHAPE 2, or none. Noise shaping essentially takes the noise floor and reshapes it in a fashion such that the ear perceives the noise floor to be quieter than it really is. See "Noise Shaping" graph on page 20. The LED will light green for Shape 1 and red for Shape 2. When the LED is off, there is no noise shaping taking place.
Selects output wordlength of 16, 20, or 24 bits output resolution. The upper LED will light green for 16 bits. The lower LED will light red for 20 bits and green for 24 bits.
Selects dither type of TPDF, SNR2 , or None. Dither is random noise that is added to the audio signal which effectively eliminates the harmonic distortion created by truncation. See “TPDF Dither” and “Truncation” graphs on pages 19 and 20. The LED will light red for SNR2 and green for TPDF. When the LED is off, there is no dithering taking place.