As the first manufacturer worldwide, SPL has
developed a stereo and multi-channel mastering console.
The goal of the development was a console which is superior
in audio quality to all known and foreseeable audio
formats, whether analogue or digital, allowing an unrestricted
reproduction of the sonic quality of SACD and DVD-Audio
and to be a safe capital investment
The MMC 1 operates in the centre of a mastering environment
fulfilling the tasks of speaker management, source connectivity,
audio metering, track assignment, master and monitor
level setting and automated insert routing of external
processors.
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Bob
Ludwig |
Fade In ...
Digital audio formats are subject to further development
and change. The degree of incompatibility enforced
by the “format war” between PCM and DSD
has persuaded us to decide for a technology that is
superior in dynamic range, headroom and sound quality
– and that is discrete analogue technology in
its most advanced implementation.
And there are further requirements speaking for
the employment of high-performance analogue technology:
The number of necessary AD/DA conversions should
be reduced to a minimum. Digital sources can be connected
to a digital router (i.e. of Z-Systems), which outputs
the selected source through the preferred DA converter
to the MMC 1. Thus it is ensured that the sound quality
remains comparable and is not affected by converter
differences.
From a sound-aesthetical view, high-quality analogue
outboard processing is superior to digital processing.
The analogue concept allows for problem-free integration
of those processors.
Monitors and power amplifiers are mostly analogue
designs. Why have another converter in that chain?
New Technologies
In the MMC 1 SPL’s new SUPRA operation amplifiers
are used throughout. They operate at 120 V operating
voltage. During a four-year period, SPL has researched
this discrete operation amplifier, until the basis
of a new generation of analogue audio technology was
found. The SUPRA operation amplifier obtains a signal-to-noise
ratio of 116dB with an headroom of 34dB. The dynamic
range amounts to 150dB with a frequency bandwidth
ranging to 200kHz.
With these basic specs, the MMC 1 is beyond the
requirements of today's PCM digital formats up to
24 bit and 192kHz sampling rate or DSD digital format
with 1 bit and 256 fs.
It is not to be expected that digital technology will
offer an environment in foreseeable time, in which
the MMC 1 could become a “bottle neck”.
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The MMC 1 configuration
in short |
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In
the Source section the Inputs (4x stereo/ 4x
8-channel) and Returns (8x stereo/ 8x 8-channel)
can be selected. |
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The
Input section offers a passive router to re-assign
the track configurations of the various surround
formats to match the SMPTE/ITU standard. Each
input channel is equipped with an On, Phase
Reverse and a special Trim switch for precise
gaining in 0.5dB steps from -9,5dB to +6dB.
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The
Insert section is quite unique. It offers control
functions for an automated patchbay, called
Insert Box. Up to eight 8-channel processors
can be connected to this outbreak 19”
unit. The mastering engineer can store and compare
up to four sequences by a push of a button.
An all-over bypass switches the Insert Box in
and out of processing. |
| • |
The
Monitor section features a central Monitor Level
control and switches for Mute and Dim levels.
Two stereo loudspeaker sets and two surround
loudspeaker sets of up to eight speakers can
be connected to the MMC 1. |
| • |
The
speaker management offers an On and a Solo switch
for each loudspeaker. The Solo function operates
as Solo-in-place. With the Solo-to-Center switch
each speaker can be monitored through the centre
speaker for better comparison. There is provision
to monitor the LFE on the L/C/R. Three Mono
functions (L/R; LS/RS; Lt/Rt) and two mode switches
for stereo or multi-channel operation round
up the Channel Selection section. The meter
bridge houses a RTW Surround Monitor 10800x
and eight big VU meters with superb ballistics.
The remote control for the RTW Surround Monitor
is already built into the console next to the
calibration switches for the VUs. The VUs can
be switched to either show input or output.
The VUs can be calibrated to eight different
values (0 dB/-2/-4/-6/-8/-10/-12/-14 dB). |
| • |
The
Master section is dominated by a second eight
channel level control. With the Master Level
control, the overall output level of the desk
to the recording sends is governed. The range
of adjustment is from -10dB to +10dB. |
| • |
The
Output section offers the same Trim switch for
precise gaining as used in the Input section.
Level differences, which may have been introduced
by outboard processing, can be compensated for
each channel in 0.5dB steps ranging from -9.5dB
to +6dB. |
The
sections in detail
Source
The Source section is divided into two departments.
On the left side are the selectors for the input sources,
which undergo the mastering process. Four stereo sources
and four 8-channel sources can be connected to the
MMC 1. On the right side are the selectors for the
returns of the recorders, DAW, analogue multi-tracks,
SACD- and DVD-Players, TV, AC3/DTS encoder/decoder
etc. The Input/Return button switches the monitoring
to a total of eight stereo and eight multi-channel
returns. The inputs and the returns can be attached
on the back of the MMC 1 both to XLR sockets and to
EDAC multi-pin sockets.
Input
The Input section receives the signal selected in
the Source section. First the signal goes through
a passive routing switch, with which the individual
channels can be routed to every other channel. This
function is essential regarding the different channel
configurations of the surround formats.
A table above the routing switch gives an overview
of the most important channel configurations:
DTS: L / R / LS / RS / C / LFE / L(t/o) / R(t/0)
Film: L / LS / C / RS / R / LFE / L(t/o) / R(t/0)
SDDS: L / LC / C / RC / R / LFE / LS / RS
The MMC 1 buss structure for all inputs and outputs
follows the SMPTE/ITU track assignment:
SMPTE: L / R / C / LF / E / LS / RS / L(t/o) / R(t/0)
Note: L(t/o) and R(t/0) explained: The appendix ‘t’
means ‘total’ and refers to the automatic
stereo downmix function within AC3-encoders, whereas
the appendix ‘o’ means ‘only’
and stands for a separate stereo mix.
The routing selector transfers each conceivable channel
configuration into the SMPTE configuration. The high-quality
switch has gold-plated silver contacts with a life
span of over 25.000 switching cycles.
Audio then runs through an On and a Phase Reverse
switch followed by the 32-position Trim switch. The
range of trimming is -9.5dB to +6dB in 0.5dB steps.
The specialty of this switch is its mechanical architecture
that interconnects only two contacts. Common switches
route the audio through a chain of resistors switched
in series. Thermal noise and tolerances are adding
up. The MMC 1 Trim switch avoids that by routing the
audio through only one 0,1% metal film resistor at
any position.
Insert
While it is relatively easy in a stereo environment
to connect processors via a patchbay and specify their
sequence, it becomes complicated and time consuming
when dealing with surround.
The MMC 1 features an Insert-Box to which up to eight
8-channel processors can be connected. The unique
advantage of MMC 1 is that the engineer can specify
up to four routings, called sequences, which can be
stored and re-called.
The Insert section provides a switch for each of the
eight external processors. Depressing them in a sequence
specifies the signal flow through the processors.
Beside each switch is a seven segment LED-display
indicating the current position of the processor in
the sequence.
The mastering engineer can use this feature to compare
between sequences in a varying order or to compare
the same type of processor like equalisers of manufacturer
A with manufacturer B.
Three memory banks are available. Together with the
current sequence, four different signal flows can
be compared instantly. A bypass switches the Insert
Box to hard-bypass.
Monitor
The audio signals returning from the Insert Box are
sent to the Monitor section and coevally to the recording
outputs. The Monitor section is divided in the following
sub sections:
Speakers
Two stereo pairs and two surround loudspeaker sets
can be connected to the MMC 1 for monitoring.
Channel Selection
Each loudspeaker can be switched on with the On switch,
which is labelled with the respective loudspeaker
position. Underneath them a Solo function is provided
for each loudspeaker. Multiple solo is also possible.
The Solo-to-Center function allows for monitoring
of each loudspeaker through the centre speaker to
obtain a better comparability. Solo-to-Center can
only be activated, if a speaker was switched to solo
before. In a multiple solo situation the Solo-to-Center
cannot be activated.
The LFE-to-L/C/R switch distributes the LFE signal
proportionately on L/C/R.
In the Monitor section two switches are provided to
change the MMC 1 configuration from stereo to multi-channel.
The stereo switch should be pressed before starting
a stereo mastering job to switch off all monitoring
functions except for L/R for improved operation safety.
When depressing Multi-Channel, the MMC 1 resets itself
to the last multi-channel configuration.
The Monitor section offers three mono functions:
1. Mono L/R
2. Mono Rear (cannot be enabled in stereo mode)
3. Mono L(t/o)/R(t/0) (cannot be enabled in stereo
mode)
Monitor Level
The Monitor Level is regulated with a genuine custom-made
potentiometer with eight chambers. The MMC 1 avoids
using DACs, steps ladders or VCAs for this operation.
The specifications of this potentiometer are impressive.
The maximum tolerance is 0,5 dB over the entire control
range! And such a masterpiece deserves an appropriate
optical frame: this noble potentiometers is moved
with an 60 mm diameter knob of massive aluminium.
The scaling is illuminated with 30 blue LEDs on a
circular area of 120 mm with a pointer element from
miniature orange LEDs.
Dim/Mute/Back
Three Dim levels are available (-10 dB, -20 dB and
-30 dB). In addition to the Mute function a switch
labelled Back is incorporated. It is used in case
a Dim function is activated and afterwards Mute was
pressed. The Back function immediately returns to
the actual Monitor Level setting without releasing
Dim and Mute.
Metering
Right of the Monitor Level potentiometers are the
switch functions for the VUs and the RTW Surround
Monitor. All functions of the RTW can be controlled
remotely. They are placed next to the Monitor Control
potentiometer for easy access. Thus the mastering
engineer does not need to leave the optimal hearing
position.
The VUs are likewise custom-made by a Japanese company,
which manufactures VUs with the optimal ballistics.
The VUs can be calibrated on eight different reference
levels (0 dB/-2/-4/-6/-8/-10/-12/-14 dB). Furthermore
the VUs can be switches to indicate either input or
output levels.
Master/Output
The MMC 1 provides three eight channel and four dual
channel recording outputs. The output section features
the same 32-position switch for level trimming in
0,5dB steps as in the input section. Additionally
a Master Output level is provided to regulate all
eight channels simultaneously. The same potentiometer
is used as for the Monitor Level regulation. With
this potentiometer, extremely fine recording level
settings are achievable to retrieve the very last
bit of the recording headroom. Owing to a genuine
potentiometer with infinite resolution a dynamic mastering
is possible
Bob
Ludwig/Gateway Mastering and DVD |
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| Galaxy
Reference Mastering Suite |
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The
MMC 1 in the center of Galaxy's
new Reference Mastering Suite.
Fritz Fey, Studio Magazin 12/01
(GER): "... a mastering-room
second to none in Europe –
if not on this planet."
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My
analog machine beats ... |
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| Monitor
and master level control |
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| Source-Section
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| Input-Section
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| Insert-Section
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| Channel
Selection |
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| Monitor
level control |
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