junger b40 User manual

4ch digital audio limiter
b41
release 2.3.0

The information contained in this manual is subject to change without notice.
This manual is the copyright of Jünger Audio. All reproduction and copying, other than for
legal owner’s personal use, or disclosure of part or whole to a third party, is not allowed
without prior written authorization by Jünger Audio. © Jünger Audio, Berlin 1998-2004
FOREWORD
Thank you for buying and for using the 4-channel Digital Audio
Limiter b41.
Not only you have acquired the latest generation of digital
dynamic range processing, but also a piece of equipment which
is unique in its design and specification.
Please read this manual carefully to ensure you have all the
information you need to use the 4-channel Digital Audio Limiter
b41.
The unit was manufactured to the highest industrial standards
and went through extensive quality control checks before it was
supplied.
If you have any comments or questions about installing, setting-
up or using the b41, please do not hesitate to contact us.
0

CONTENTS
2. Function description .......................................….
2.1 Basic description ...........................................
2.2 Block diagram .............................................
2.3 Audio signal processing ................................
2.3.1 Gain .......................................................
2.3.2 Limiter Threshold............................
2.3.3 Limiter Program....................................
2.3.4 Influence of the signal delay time
2.3.5 Transparent mode ............................
2.4 Remote system ……………………………….
3. Installation .........................................................
3.1 Unpack the unit ...........................................
3.2 Power supply ................................................
3.3 Connections ...........................…...................
3.4 Rack mounting ..........................…................
3.5 Operation safety ..........................……..........
3.6 Synchronization of digital output ..….............
3.7 Remote Control ..................……...................
3.7.1. GPI Remote Control ......…….............
3.7.2. Tally Out .............………....................
3.7.3. Serial Remote Control .......…….........
4. Location of parts and controls ............………......
4.1 Front panel ......................……......................
4.2 Rear panel ...........................………..............
4.3 Switches and jumpers for configuration ........
4.4 Selection of SDI Split Mode ......…….............
4.5 Selection of SDI audio group ........................
2-1
2-1
2-2
2-3
2-3
2-3
2-3
2-3
2-3
2-3
2-4
3-1
3-1
3-1
3-1
3-1
3-1
3-2
3-3
3-3
3-4
3-5
4-1
4-1
4-3
4-4
4-5
4-5
1

5. Operation ...............................................................................
5.0 Description of setup operation ...........................................
5.1 Mode .............................................................................
5.2 Recalling, saving and editing of presets ...........................
5.3 Input selection …….............................................................
5.4 Transparent mode ............................................................
5.5 Program .…………………………………………………….
5.6 Link …….. ........................................................................
5.7 Threshold ..........................................................................
5.8 Bypass .............................................................................
6. Boot display and trouble shooting ............................................
6.1 Boot display .......................................................................
6.2 Error messages and trouble shooting ................................
6.3 Initialization the unit ............................................................
7. Application notes ......................................................................
7.1 B40 series with SDI interface .............................................
7.2 Basic working modes with SDI ...........................................
7.3 Remote control with brc …..................................................
8. Technical specifications ...........................................................
9. Warranty and service information ...........................................
5-1
5-1
5-2
5-2
5-4
5-4
5-4
5-4
5-5
5-5
6-1
6-1
6-1
6-2
7-1
7-1
7-1
7-3
8-1
9-1

2. FUNCTION DESCRIPTION
operation manual b40, chapter 2 -Function description- page 2-1
FUNCTION DESCRIPTION
The digital dynamics processor b41 is a professional studio
device that processes the dynamic range of digital audio
signals.
The dynamic range processor principles developed by Jünger
Audio enables the limiter to work with exceptionally high audio
quality, without coloration, pumping, breathing, distortion or
modulation effects sometimes associated with this type of
processor.
In short almost inaudible processing - with ease of use. The
outstanding quality of the processing is based on the Multi-Loop
dynamic range control principle developed by Jünger Audio.
The unit is easy to operate and requires only a limited number of
settings to be made by the user to achieve optimum results. All
other parameters necessary for inaudible processing are
continuously automatically controlled in response to changes in
the programme signal.
features
• 4-channel digital audio limiter
• various link modes: 4-ch, stereo 1/2 or 3/4, ch1...4
independent
• adjustable input gain (channel independent) -15...+15 dB
• adaptive controlled dynamic range processing
limiter on/off, THRS 0...-20 dBFS, PROgram 1..4
• user friendly preset and recall function (10 presets)
• pairwise bit transparent mode input to output
• extern sync mode, AES/EBU or VIDEO (or SDI if
optional SDI-interface is present)
• RS-422 interface for serial remote
• GPI interface for parallel remote control, tally output
2.1
BASIC
DESCRIPTION
2

2. FUNCTION DESCRIPTION
page 2-2 operation manual b40, chapter 2 -Function description-
2.2
BLOCK DIAGRAM

2. FUNCTION DESCRIPTION
operation manual b40, chapter 2 -Function description- page 2-3
All signal processing is done in the digital domain by Texas
Instruments floating point signal processors. The use of 32 bit word
length for calculation ensures that there is no deterioration in signal
quality, even if an audio signal with a maximum word length of 24 bit is
input into the processing of the unit.
GAIN means linear amplification of input or output signals. The input or
output gain can be changed in steps of 0.1 dB , within a range from -
15...+15 dB.
Adjustment of GAIN is channel independent.
The static characteristics of the b41 usually refers to a digital output
level of 0 dBFS (dB Full Scale). This is useful for most applications of
the dynamics processor as the on-following digital recording system is
supposed to be balanced down to the final bit.
For applications using headroom the output level of can be adjusted
within 0 ... -20 dBFS in steps of 0.1 dB. The limiter threshold
determines the maximum output level.
It is possible to choose one of four different programs for the
dynamics processor. Each provides ideal dynamics control for a
different kind of program signal as follows:
1 - universal
2 - classic
3 - pop music
4 - speech
Selecting a particular program sets up the optimum parameters of the
Limiter (attack and release times, threshold levels and interactions
between the multiple signal dependent control circuits) for a particular
kind of program material.
The time constants related to the transient response of the control
circuit are important for distortionfree processing. They are always
adaptively controlled. The algorithm has to guarantee best reaction for
fast increasing level of transient signals anytime even if classical music
with slow dying out characteristic is processed. In all cases the attack
time of the limiter for very short transients is zero.
The release time of the control circuit has influence to the increase of
loudness.
The selection of the parameter PROGRAM changes the range of time
constant values as follows:
PRO processing time corresponds to program
----------------------------------------------------------------------------------------------
5 ms to 0.5 sec LIVE
15 ms to 1.2 sec SPEECH
30 ms to 2.5 sec POP
70 ms to 5.0 sec UNIVERSAL
50 ms to 8.0 sec CLASSIC
2.3
AUDIO SIGNAL
PROCESSING
2.3.1
GAIN
2.3.2
LIMITER
Theshold
2.3.3
PROGRAM

2. FUNCTION DESCRIPTION
page 2-4 operation manual b40, chapter 2 -Function description-
The audio signal delay through the dynamics processor is approx.
2ms due to delaying of the audio signal using internal memory. A
small delay is deliberately introduced to the audio signal in order to
allow limiter and compressor algorithms which can 'preview' the audio
signal before changing it. That is the signal curve can be changed
before maximum level is reached. This delay must be considered
before attempting to mix signals processed by the dynamics
processor with other undelayed signals.
When mixing together a delayed signal and a direct signal there may
be cancellation of the signal waveform at some frequencies and re-
inforcement of the waveform at other frequencies (comb filter effect).
Corresponding 2ms delay of direct signals should therefore be carried
out before mixing them with delayed processed signals.
In case that the input signal (audio pair 1/2 or/and 3/4) is not audio (but
AC-3, Dolby E, MPEG..) the input can be feeded directly to the related
output bit transparent (no bit changes). The unit is switching to
transparent automatically if “non audio” flag in the Channel Status Bit of
the AES signal is set. Otherwise transparent mode can be set manually
by the user.
The digital audio limiter b41 is fitted with an serial remote interface in
RS-422 format.
Every device needs a device address to be registered in a remote
system. The address can be selected with the ADDR switch on the
rear panel. 16 addresses are selectable (0..F).
The changed address is valid with next power-on reset.
Up to 16 limiter b41 can be controlled from one remote panel.
Device model name and device address are to recognize using the
remote protocol of serial remote interface by an automation system or
by PC. With it various boxes can be combined in one remote system or
remote chain. However a maximum of 16 devices per model can be
controlled in one chain.
2.3.3.
INFLUENCE OF
SIGNAL DELAY
TIME
2.3.4
TRANSPARENT
MODE
2.4
REMOTE SYSTEM