Behringer SRC2000 - Manual (Page 20)

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the model collapses! The mixing console can only lock to one master source, the audio data received from the
other device would be processed wrongly since no synchronization data are available. The only thing one would
hear is interference.
The synchronization requirements in a digital studio can be met by connecting a central sync master. For
instance, the mixing console may act as master and controls all other devices by transmitting a reference
code (word clock). However, this is only possible if any slave device in the network features a sync input. In a
recording studio with digital recording devices, digital effect units, and hard disk recording systems, conven-
tional CD players and DAT recorders cannot be connected to the mixer since they do not provide synchroniza-
tion facilities.
The ULTRAMATCH solves this problem by defining any connected device as slave if the external sync input is
used. It acts as interconnection, and the transmission ratio of 65536:1 always provides a gap in the gear. The
signal received from the device to be synchronized is re-synchronized to the wordclock source during the
sample rate conversion (see also 1.1).
Thus, any device in a studio with central sync source can be connected to any other device via the ULTRAMATCH
independently of the original abilities.
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In this mode of operation, the setting of the SAMPLE FREQ switch has no effect on the sample
rate, but an identifying information (32 kHz or 44.1 kHz) is generated as part of the output
signal! This is important since DAT recorders cannot be switched over to record mode if a
wrong sample rate is recognized.
6.1.5 Correction of unformatted passages
Especially with DAT recorders it can happen that due to bit by bit recordings there remain gaps of the formatted
stream between the several recordings. In addition to that often short rests of samplerate information remain on
the tape when old recordings are taped with new material. In these cases the ULTRAMATCH converts the
peaces of information in a reliable stream of data with a fixed sample frequency. Even if the DAT recorder or any
other digital source is stopped or switched off, the ULTRAMATCH continues producing a constant signal (of
course without audio information).
6.2 SCMS Removal
The copy protection originally included in DAT recorders was simple yet effective: recordings from CD were not
possible on the digital level. Later, the SCMS standard was introduced, allowing at least one single digital
copy. The action of SCMS depends on the generation (i. e. how many copies have been drawn previously) and
the origin (category) of the digital audio material. In professional recording, copy protection makes no sense
(actually, no copy protection has been defined as part of the AES/EBU standard).
Since a lot of recording studios employ inexpensive consumer devices, problems related to copy protection
and differences in format (consumer vs. professional) are a daily occurrence. The ULTRAMATCH ignores any
SCMS information and generates a new, entirely SCMS-free information, thus allowing multiple copies on the
digital level. Therefore, the ULTRAMATCH may also serve as an aid between two consumer DAT recorders.
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At this point we would like to point out again that, in spite of the possibility to remove the copy
prohibit bit, author- and copyrights always have to remain preserved. This device was not
developed to create illegal copies!
6.3 Line Booster, Signal Refresher
Long cables or the use of a patchbay often lead to a deterioration in signal quality, resulting in increased noise
or even a connection breakdown. Due to a special input circuitry, the ULTRAMATCH removes jittering, interfer-
ence, and level drops, and transmits a perfect output signal. Hence, the ULTRAMATCH can also be used to
refresh signals affected by long cables or to reconstruct weak and falsified signals.
6.4 Sample Rate Correction
The sample rate of a device is often subject to slight deviations due to environmental temperature and aging.
Normally, an automatic interception circuit (PLL) corrects unsteady and slightly deviating rates, thus providing
trouble-free operation. However, if such deviations exceed a certain limit, the receiving unit cannot synchronize
6. APPLICATIONS