Audio ADC and DAC, Bi-directional Converter with Delay User Guide ENSEMBLE D E S I G N S Revision 1.7 SW v1.0.3 This user guide provides detailed information for using the BrightEye™ 30 D Audio ADC and DAC, Bi-directional Converter with Delay unit.
BrightEye 30 D Audio ADC and DAC, Bi-directional PRODUCT OVERVIEW BrightEye 30 D is a flexible audio converter that can function as a two channel bidirectional ADC and DAC, or as a four channel ADC or DAC with audio delay adjustment. BrightEye 30 D can function as a delay unit for two channels of analog audio. BrightEye 30 D can also be used as a sample rate converter.
The converted signals pass through a four channel mixer/shuffler providing individual adjustment of gain and channel inversion (to address out of phase inputs). The four output channels are each formed by summing any combination of inputs. Each output can contain any of the input channels, allowing, for example, stereo to mono mixdown, left/right channel swaps, and simultaneous stereo and mono outputs. Finally, these four processed signals are output in digital form through the two AES connectors.
BrightEye 30 D Audio ADC and DAC, Bi-directional The four incoming digital audio signals feed the four channel mixer/shuffler. As with analog to digital mode, this provides individual adjustment of gain and channel inversion (to address out of phase inputs). The four output channels are each formed by summing any combination of inputs. Each output can contain any of the input channels, allowing, for example, stereo to mono mixdown, left/right channel swaps, and simultaneous stereo and mono outputs.
The four channel mixer/shuffler is sub-divided into two, two channel mixer/shufflers. The digital to analog path is supported by channels 1 and 2. The reverse path (analog to digital) uses channels 3 and 4. Channel assignments are limited to only allow assignment of inputs 1 and 2 to outputs 1 and 2; and inputs 3 and 4 to outputs 3 and 4. The channel 1/2 outputs of the mixer are presented on analog outputs 1/2; and mixer's channel 3/4 outputs drive the 3/4 AES output connector.
BrightEye 30 D Audio ADC and DAC, Bi-directional 5. Sample Rate Conversion (and two channel Digital to Analog Conversion) When configured as a digital sample rate converter, BrightEye 30 D is a two channel device, processing the channel 1/2 AES input connector and outputting to the channel 3/4 AES output connector. The same signals are also output in analog form on channels 3/4. The channel 1/2 AES input will accept signals with sample rates from 44.1 to 96 kHz.
APPLICATIONS The BrightEye 30 D can be used for four channel analog to digital or digital to analog conversion, as well as two channel bi-directional conversion. Additionally, the BrightEye 30 D can provide two channel sample rate conversion with two channel digital to analog conversion. These preset modes can be further adjusted to fit particular applications (with channel mixing and other features.) Some of the many possible applications are explained and illustrated below.
BrightEye 30 D Audio ADC and DAC, Bi-directional Bi-Directional Conversion Mode Use BrightEye 30 D in Bi-Directional mode to simultaneously convert analog signals to digital for input to a digital media capture card in a desktop video system AND convert the digital audio output back to analog for monitoring.
REAR CONNECTORS All connections to the BrightEye 30 D are made on the rear of the unit. Refer to the illustration below. BrightEye 30 D Rear Connectors Power Connection A modular power supply is supplied with the product. Connect it to the 12 volt DC power input connection on the far left. Use the locking ring to secure it. USB Connector The USB connector is used to provide more comprehensive control, diagnostics, and upgrades to the converter from a PC.
BrightEye 30 D Audio ADC and DAC, Bi-directional OPERATION Control and operation of the BrightEye 30 D is performed from the front panel or with the BrightEye PC Control application. Some control settings are only available with BrightEye PC. These parameters cannot be monitored or controlled with the front panel. Front Panel Controls and Indicators The front panel of the converter, shown in the figure below, provides status indicators and control over video input and output selection, and gain.
below -20 VU. The Gain indicator illuminates red when the gain level has been adjusted off from unity by the user. The 0 VU point corresponds in the digital domain to the digital reference level (-18 or -20 dBFS) and in the analog domain to the analog reference level (-10 or +4 dBu.) Power (Pwr) Illuminates green when power is applied to the converter and the internal voltage regulator is functioning correctly.
BrightEye 30 D Audio ADC and DAC, Bi-directional Analog Ref Level This control selects analog reference levels for input and output, with the following choices: -10 dB – Accept -10 dB inputs, and provide -10 dB outputs +4 dB – Accept +4 dB inputs, and provide +4 dB outputs Delay This control selects the Audio Delay. Delay can be adjusted from 0 to 1000 msec in increments of 1 msec, using the left and right buttons when this control is selected on the front panel.
• Mode – select device conversion mode. This pulldown lets you choose between: Analog to Digital, Digital to Analog, Bi-Directional, Two Channel Analog Delay, and Sample Rate Convert. • AES 1/2 and AES 3/4 Status – these controls indicate the status/behavior of the AES I/O connections. They show: No Input, Audio Present, Data Present, Input Mode, or Output Mode. • Analog Ref Level– selects analog output reference level for input and output. This pulldown lets you chose between: -10 dBu or +4 dBu.
BrightEye 30 D Audio ADC and DAC, Bi-directional the control indicates the amount of gain applied to the channel in dB. The gain level can be adjusted by moving the vertical slider control, or entering a desired level directly in the field (from -70 dB to +12 dB.) On the righthand side of the control are Output Bus Assignment buttons. These buttons control which analog output channel the AES channels are mapped to. It is possible to map an Input channel to anywhere from zero to four output channels.
WARRANTY AND FACTORY SERVICE Warranty Ensemble Designs, Inc. warrants this product to be free from defect in material and workmanship for a period of two years from the date of delivery. During this two year warranty period, Ensemble Designs, Inc. will repair any defective units at Ensemble’s expense if the unit should be determined to be defective after consultation with a factory technician. This warranty is not transferable. Any implied warranties expire at the expiration date of this warranty.
BrightEye 30 D Audio ADC and DAC, Bi-directional SPECIFICATIONS AES/EBU Digital Inputs: Number: Two (total of four channels, selectable as inputs or outputs) Type: AES3id Connectorization: Coaxial, 75 Ω BNC Bit Depth: 20 and 24 bit Sample Rate: 30 KHz to 100 KHz (Sample Rate Converted internally to 48KHz) Reference Level: -18 or -10 dBFS (selectable) AC-3, Dolby-E: Supported when inputs are synchronous AES/EBU Digital Outputs: Number: Two (total of four channels) (selectable as inputs or outputs) Type: AES
GLOSSARY This is a brief glossary of commonly used terms associated with this product. AES/EBU The digital audio standard defined as a joint effort of the Audio Engineering Society and the European Broadcast Union. AES/EBU or AES3 describes a serial bitstream that carries two audio channels, thus an AES stream is a stereo pair. The AES/EBU standard covers a wide range of sample rates and quantization (bit depths.) In television systems, these will generally be 48 KHz and either 20 or 24 bits.
BrightEye 30 D Audio ADC and DAC, Bi-directional Component In a component video system, the totality of the image is carried by three separate but related components. This method provides the best image fidelity with the fewest artifacts, but it requires three independent transmission paths (cables). The commonly used component formats are Luminance and Color Difference (Y/Pr/Pb), and RGB. It was far too unwieldy in the early days of color television to ever consider component transmission.
EDH Error Detection and Handling is a method to verify proper reception of an SDI or HD-SDI signal at the destination. The originating device inserts a data packet in the vertical interval of the SDI signal and every line of the HD signal which contains a checksum of the entire video frame. This checksum is formed by adding up the numerical values of all of the samples in the frame, using a complex formula.
BrightEye 30 D Audio ADC and DAC, Bi-directional Interlace Human vision can be fooled to see motion by present a series of images, each with a small change relative to the previous image. In order to eliminate the flicker, our eyes need to see more than 30 images per second. This is accomplished in television systems by dividing the lines that make up each video frame (which run at 25 or 30 frames per second) into two fields.
NTSC The color television encoding system used in North America was originally defined by the National Television Standards Committee. This American standard has also been adopted by Canada, Mexico, Japan, Korea, and Taiwan. (This standard is referred to disparagingly as Never Twice Same Color.) Optical An optical interface between two devices carries data by modulating a light source.
BrightEye 30 D Audio ADC and DAC, Bi-directional RGB RGB systems carry the totality of the picture information as independent Red, Green, and Blue signals. Television is an additive color system, where all three components add to produce white. Because the luminance (or detail) information is carried partially in each of the RGB channels, all three must be carried at full bandwidth in order to faithfully reproduce an image.
YUV Strictly speaking, YUV does not apply to component video. The letters refer to the Luminance (Y), and the U and V encoding axes using in the PAL composite system. Since the U axis is very close to the B-Y axis, and the V axis is very close to the R-Y axis, YUV is often used as a sort of shorthand for the more longwinded “Y/R-Y/B-Y”. Y/Cr/Cb In digital component video, the luminance component is Y, and the two color difference signals are Cr (R-Y) and Cb (B-Y).
BrightEye 30 D Audio ADC and DAC, Bi-directional BrightEye-24
