Our aim in the development of 120V mastering equipment was the creation of a technology that would be superior in audio quality to all known and foreseeable audio formats, whether analog or digital. Such a console would provide both for an unaltered reproduction of the sonic quality of SACD and DVD-Audio and in the process, remain a safe capital investment for many years.
Digital audio formats have undergone continuous development and change and will continue to do so. The degree of incompatibility created by the “format war” between PCM and DSD is a main argument for a technology that is superior in dynamic range, headroom and sound quality to either or any other such format – and that is discrete analogue technology in its most advanced implementation.

Moreover additional aspects speak for the employment of high-performance analog technology:

• The number of necessary AD/DA conversions should be reduced to a minimum. With the MMC2, digital sources can be connected to a digital router, which outputs the selected source through the preferred DA converter. This ensures that the sound quality remains comparable and is not affected by converter differences.
• From a purely aesthetic standpoint, high quality analog outboard processing consistently proves itself superior to digital processing. The analog concept allows for problem-free integration of such analog processors.
• Monitors and power amplifiers are almost exclusively analog in design. Yet another converter at this point in the chain only degrades monitoring signal paths. Furthermore DSD signals cannot be monitored on a digital monitoring that operates in PCM.

New Analog Technology
SPL’s SUPRA operation amplifiers are used throughout. They perform at an industry benchmark of 120 volt. The SUPRA op amp achieves a signal-to-noise ratio of 116dB with a headroom of 34dB. The dynamic range amounts to 150dB with a frequency bandwidth of 200kHz.
With such specifications, the MMC2 rides comfortably beyond the requirements of either the current maximum 24Bit/192kHz PCM format or 1Bit/256 fs DSD format.

MMC2 Configuration

Source
The Source section is divided into two parts: Stereo and Multi-Channel Inputs and Stereo and Multi-Channel Returns. The inputs are fed to the mastering path. The MMC2 accepts two stereo inputs and two 8-channel inputs here.
The Return On switch allows for selection of two stereo and four multi-channel returns in total to offer selection options for returns from recorders, DAW, SACD and DVD-Players, AC3/DTS encoder/decoder, and so on.

Input
Signals selected in the Source section are routed to the Input section. The signal passes a passive Phase Reverse switch, followed by the detended Trim control. The trimming range covers –10dB to +10dB in 0.5dB detentions. The trimming stages can be switched out of the signal path entirely.

Insert
The signal is now routed to the Insert send/return connector. The MMC2 offers a switchable Insert point to include external processors into the signal path.

SPL MasterBay (Option)
While it is relatively easy in a stereo environment to connect processors via a patchbay and specify their function in the audio path, this job is getting much more complicated and time consuming when dealing with surround. To help alleviate this complexity, the MMC2 can optionally be complemented with an automated 8 x 8 channel Patchbay called SPL MasterBay.
The MasterBay consists of an 8U Insert Box and a remote control. Up to eight, 8-channel processors can be connected to the Insert Box which is operated by the remote.

MasterBay Remote
The MasterBay Remote provides a button for each of the eight external processors. Depressing these in sequence switches among choices in processor signal flow. Beside each button a seven segment LED-display indicates the current position 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 processors.
Up to three processing sequences can be stored by the push of a button and together with a present sequence up to four different processor sequences can be compared.
A global bypass switch on the MMC2 activates or deactivates the MasterBay and all connected inserts. Please refer to the SPL MasterBay information for further details.

Output
The audio signals returning from the Insert are sent to the Output section and afterwards simultaneously to the Monitor section and the recording outputs. The Output section offers the same trim controls as the Input section. In each channel level differences which may have been introduced by outboard processing may be compensated for in a range from -10dB to +10dB. The trimming stages can be taken out of the signal path entirely with individual bypass switches.

Master Fader
The Master Fader is regulated by an eight-tiered high-end potentiometer with a minimum tolerance over the entire range in all 8 levels. This control dispenses with step ladders, DACs or VCAs and the specifications of this potentiometer are substantially better than either of these other options could be.
The Master Fader allows for dynamic mastering as well as fine tuning the overall level from +10dB to -80dB. With this control's extremely high, if not infinite resolution, the engineer can attain every ounce of recording headroom. The result is an unparalleled excellence in dynamic mastering.
Each channel can individually be activated with the Fader On switch. If switched to bypass, the fader is taken out of this audio path entirely.

Recording Outputs
The MMC2 provides two 8-channel and four dual-channel recording outputs.

Monitoring
Two stereo pairs and two surround speaker sets can be connected for monitoring the outputs. Three different Dim levels and Mute can be selected by the push of a button.

Monitor Level
The global Monitor Level is regulated with the same eight-tiered, high-end potentiometer as used for the Master Fader.

Speaker Management
The speaker management allows for monitoring of an input, output and return. There is an On switch for each speaker, and each is shown with its respective position. A solo switch is placed right below each speaker switch. It usually operates as Solo-in-Place. A global Solo-to-Center switch routes the selected speaker signal to the center speaker if needed for better comparison.
LFE signals can alternatively be routed to the L/C/R speakers for monitoring through the front speakers.
Two mode buttons change the MMC2 configuration from stereo to multi-channel operation. To switch off all monitoring functions other than L/R, the stereo button is activated before starting a stereo mastering job. When the Multi-Channel button is activated again, the MMC2 restores full multi-channel functionality.
Three Mono functions (L/R; LS/RS; Lt/Rt) round out the Speaker Managemant section.