Bel Digital Audio 7150 Audio Delay
Audio Synchronisation Delay
The Bel 7150 is a 2-channel audio delay unit designed for installation in a broadcast transmission chain, and allows the operator to add precise amounts of delay to the signal.
The Bel 7150 is a 2-channel audio delay unit designed for installation in a broadcast transmission chain, and allows the operator to add precise amounts of delay to the signal. Typically for resolving lip-sync issues. It is ideal for all situations where the accompanying video signal has undergone delay as a result of processing, standards conversion, satellite uplink, encoding for web streaming, etc., but is also useful for non-video situations such as synchronising multiple radio network transmissions.
Inputs and outputs are available in both balanced analogue and AES3 formats (all on XLRs). Both analogue and digital outputs are always active, giving the 7150 additional versatility as either a stereo A-to-D converter or a stereo D-to-A converter. Input gain and output level adjustment are available for the analogue signals.
Controls are minimal, and the simple menu system is designed for “set and forget” operation. The maximum delay available is 10.4 seconds, and the delay time can be adjusted in video fields or frames (selectable to suit PAL or NTSC standards), milliseconds, or samples. Once set, the unit’s parameters may be saved into one of eight internal memories for easy recall from the front panel. The first four memories may also be recalled through contact-closure GPIs on a rear panel D-sub connector. The front panel controls may be locked to prevent tampering or inadvertent alteration during transmission.
Nominally operating at 48 kHz sample frequency, the 7150’s AES3 inputs are fitted with sample rate conversion (SRCs), ensuring reliable operation in the range 32 to 50 kHz. The 7150 is completely transparent to AES3 signals encoded as Dolby® E, Dolby® Digital or Dolby® Digital Plus: a menu setting enables Transparent Mode that guarantees the integrity of the data stream when delaying such signals. An external sync input is provided on the rear panel to ensure continued lock, whichever input is in use.
The 7150 is designed for 24/7 operation; the delay may be bypassed with a dedicated front panel button, and internal fail-safe relays ensure signal continuity in the event of power failure. The unit is built to a very high mechanical standard in a stainless steel 1U 19” enclosure.
- 1U Broadcast quality 2-channel audio delay unit
- Maximum delay time 10.4 seconds
- Delay time adjustable in frames or fields (PAL or NTSC), milliseconds or samples
- Balanced analogue and AES3 inputs and outputs
- Analogue input gain and output level are adjustable
- Can be used as a stereo A-to-D or D-to-A converter
- Fully compliant with Dolby® E, Dolby® Digital and Dolby® Digital Plus bitstreams
- Hard relay bypass in event of power failure
- Control lock to prevent tampering
- External sync input
- Eight user memories for storing standard set-ups
- 4 GPI inputs for memory recall
- Extremely reliable - designed for 24/7 on-air use