Intended for use in professional applications such as the transfer of digital audio between different digital equipment, these units have AES/EBU and SPDIF inputs and outputs, so may transfer from either standard to the other. Output sample rate is matched to one of a wide range of frequencies or synchronised to either AES/EBU, SPDIF or TTL external synchronising inputs, as selected by DIP switches.
RB-SC1 sample-rate converter has two female 3-pin XLR connectors for AES/EBU, and two RCA (phono) sockets for S/PDIF, as well as a female BNC connector for a word-clock input. The unit can handle audio signals with 16, 20 or 24-bit word-lengths. AES/EBU and S/PDIF output connectors are 3-pin male XLR and RCA respectively, and internally-generated sample-rates of 32kHz, 44.1kHz, 48kHz, 64kHz, 88.2kHz or 96kHz are set by a rotary switch.
Dynamic range: 120dB. Distortion and noise: -114dB THD + N, at 1kHz, referenced to 0dBFS. Power source: 85-264V AC @ 47-63Hz 10W maximum, IEC inlet, lead supplied, UK13A plug
Optional accessories: RB-RK1 front panel rack kit, RB-RK2 rear-panel rackmount kit.
RB-SC2 is an enhanced version of the RB-SC1 providing the following additional features:
It supports higher sample-rates up to and including 176.4kHz and 192kHz; two independent sample-rate converter circuits use a common clock-source to set the output sample rate; two video synchronising boards are available as options, these set the output sample-rate to 48kHz, synchronised to either an analogue video signal or SDI digital video signal (HD or SD); the 'X-Lock' sync mode allows the unit to function as a full bi-directional sample rate converter; a serial RS232 port is included so that the RB-SC2 settings can be controlled remotely.
Standard external sync modes are from the AES/EBU sync input, the Wordclock input or, for X-Lock, the other digital input. The X-Lock synchronisation allows the unit to act as a bi-directional sample rate converter with the output of sample rate converter one syncing the input of sample rate converter two and vice versa so that they follow each other. The application for the X-Lock mode is so that the RB-SC2 can be inserted between two digital devices which run at different sample-rates, such as a PC recorder and a digital player. Using X-Lock mode ensures that the two devices remain synchronised at all times regardless of the sample-rate of the two.
In the synchronisation 'Master' mode the output sample-rate is simply set by, and locked to, the internal on-board clock generator. No sync signal is used or required. In 'Auto- sync' mode output sample-rate follows the selected sync input. When the sync signal is not present the output sample-rate will be set by, and locked to, the internal on-board clock generator at the selected output frequency. In 'Auto Lock' mode no output will be generated until lock is achieved with a sync signal. The output sample-rate then follows the sync input. If the sync signal is removed then the output sample-rate will be set by, and locked to, the internal on-board clock generator at the closest frequency available to the previous sync input. In 'Slave' mode the output sample-rate follows the sync input. When the sync signal is not present the digital output is turned off.
The front panel, with the familiar Redbox red-anodised finish, has five momentary switches each with an arc of LED indicators. The first 'FREQUENCY' switch selects the sync frequency to be used when the unit is using the internal clock. The 'CS DATA' button defines the content of the channel status bits embedded within the digital audio stream, and can be forced to either professional mode, consumer mode or to follow the mode of the input. The 'INPUT 1' selects which input source is used for input one, from a choice of the AES/EBU, S/PDIF or TOSlink inputs. Three LEDs above the button illustrate which source is selected. The 'INPUT 2' switch provides the same functionality for input two. The 'SYNC' button allows the user to cycle through the synchronisation modes. The LEDS around the button display which mode has been selected.
The rear panel has two groups of connectors providing inputs and outputs for channels one and two respectively. Each has two XLR connectors for balanced AES/EBU digital connections, two RCA (phono) connectors for S/PDIF and two TOSlink optical connectors. An XLR provides an input for AES/EBU sync and a BNC for word-clock. The aperture for the BNC connector of optional video sync boards is capped. The serial port connector is a 9-pin D-sub types. Power is connected by an IEC inlet.
Sample frequencies: 32, 44.1, 48, 88.2, 96, 176.4 or 192kHz. Power source: 85-264V AC, 47- 63Hz, 10W maximum. Dimensions (WxDxH): 480 x 108 x 42mm, 1U. Weight: 1.4kg.
Included accessories: Manual, AC power cable.
Optional accessories: RB-RK3 rack kit, RB-SYA, RB-SYD.
These sync boards, compatible with RB-SC2, RB-TGHDX and RB-TGHD8 mount inside the case, with a BNC connector protruding through a pre-punched aperture. They can be used to synchronise the outputs to a 48kHz sample rate.
RB-SYA analogue sync board will accept a composite signal of NTSC (525), PAL (625) and SECAM (625) signals covered by SMPTE-170-M (NTSC) and ITU-R BT.470-6 (PAL and SECAM).
RB-SYD digital video sync board will accept 270Mbps SD-SDI and HD-SDI signals covered by SMPTE-259-M-C (SD) and SMPTE-292M (HD).