Surround Master Module for
V700 Stem Mixing Consoles
The M755 is the stem mixing master module for surround consoles. It includes the 5.1 surround master chain with the status control for stereo mode and additional downmix matrix stages, the auxiliary masters for the 3 mono aux sends and the 2 stereo cue sends, the PFL master, an additional stereo return input and a headphone amplifier.
Stereo Return Input Section
The stereo return input completes the feature set of the master module. The return will usually be used for the output of a reverb device but can be used with any stereo line level signal as well. The input is balanced and can process levels of + 30 dBu. The input level is fixed and calibrated to a nominal value of + 6 dBu ~ + 4 dBV. The CUE pot drives the stereo send CUE1 pre fader. The Cut, PFL, Meter, and Solo section as well as the fader and the surround panorama section are not different from the M769 Stereo to Surround Input Module; however, the output of the pan control drives the main master only. A group select section is not included.
The mix bus amps are fed from the surround master bus rails in the console frame. The bus amp outputs drive the mix insert section, that is balanced and buffered. The insert outputs are always available on the connector panel. The insert inputs are switched into the signal chain with the INS switch. The entire surround insert section can process levels of 30 dBu. The master fader is always post insert. It is implemented with high performance, wide bandwidth VCA's that drive special output buffer amplifiers. Audio master faders are available on special order. The LFE pot allows to adapt the level of the LFE channel in a range of +/- 10 dB to the needs. The integrated downmix matrix provides a stereo output signal that is always available in parallel. The two pots, C->LR and S->F control the matrix levels. Both controls have calibrated center positions with 6 dB attenuation for the center channel and the surround channels. The control ranges are from off to 0 dB. The downmix matrix adds the left surround channel to the left stereo channel and the right surround channel to the right stereo channel. The level is determined by the S->F control. The center channel is mixed to the left and right stereo channels. The center level is determined by the C->LR control. The LFE channel is low-pass filtered with a corner frequency of 80 Hz and mixed to the left and right stereo channels with 0 dB. Custom filter frequencies are possible as well. All outputs are electronically balanced and can handle + 30 dBu. Transformer balanced outputs are also possible; however, the optional transformers have to installed in a separate module due to the lack of space in the master module for appropriate output transformer that can process + 30 dBu at low frequencies.
Aux and Cue Masters
The master amplifiers for the three mono aux sends and the two stereo cue sends are also included in the master module. Each send has a rotary master level control with a maximum gain of 6 dB and an AFL switch that routs the output signal post master fader to the PFL bus of the console. All output amplifiers are electronically balanced and can deliver levels of + 30 dBu.
PFL and Headphone Amp
The PFL master amplifier is part of the master module. The electronically balanced output is available on the connector panel. In addition, it switched to the internal headphone amplifier, if one or more PFL switches in the console are active. A LED next to the TRS jack indicate PFL mode. The headphone amplifier allows baisc control without additional, external equipment. If PFL is not active, the stereo output of the downmix matrix drives the headphone amp. The amplifier has a volume control pot and can be used with any headphones.
Mode Stereo Status
The mode stereo status switch ST allows to select the operation mode of the entire console. If ST is pressed, stereo operation is selected. Only the LCR pans in all panorama sections in the console are active now and operate like standard stereo pan pots. The mix master busses operate also in stereo mode, C, SL, SR, and LFE are muted, while Front Left and Front Right are used for the stereo channels. The stereo status avoids hazzles with the settings of the surround pan controls. The entire console behaves like a normal stereo console.
The M755 surround master is a 6U, 1.5 slot wide V700 module with 120 mm depth that can be used with standard and custom build stem mixing frames.