The Master Section E2 can contain up to eight Stereo Effect Returns. The Stereo Return Section is part of every module. The feature list includes input routing, input gain control, a hi-low equalizer, cue send, 24 bus routing, rotary fader and balance control, peakled, PFL, solo circuitry and two mute groups.

Each Module of the Master Section E2 contains a Stereo Effect Return with stereo line input, equalizer, 24 bus routing matrix and stereo cue send.

Nowadays, almost all effect devices have stereo outputs. Therefore, a stereos effect return input makes more sense than a mono unit In addition, an effect return input is only useful, if the effect device can remain connected without the need to move it to other channels for a special task. All funtion blocks that are needed during a production must be existing. To control the level and feed the signal into the stereo master is only the basic task. While recording, it is often necessary to send a particular effect to the multitrack, since the effect device is needed for another purpose while mixing. Besides, the common problem of effect devices in combination with audio subgroups makes it necessary to assign the effect return of a device, which input comes from sends of channels that are routed to an audio group, to the same audio group. If this principle is not considered, changing the group master level will result in different effect level. To cover these problems it is necessary to integrate a routing matrix that give access to all busses.

While recording it is often necessary to send an effect signal to the playback headphones, to improve the quality of the playback mix. This mix must operate independently and can not affect or alter the recording of an effect or the monitor mix for the control room. In addition, at least a simple EQ is desirable. We have combined these basic functions with some additional features.

The input of the stereo return section is available on the connector panel and on the patch bay. If the multipin connector on the connector panel is used for the fixed connection of the effect outputs to the return inputs, these outputs are available on the jacks in parallel. Special installations, normalized jacks, etc. are possible in several ways; please ask.

The switches L and R determine the routing of the input signal. If L is selected, only the left input channels feeds both stereo channels; if R is selected, only the right channel drives both internal stereo channels. Pressing L and R at a time reverses the input channels and the Phase switch reverses the phase of one input channel. The input is electronically balanced. The input level is calibrated (0 dB) unless the GAIN switch is pressed and the gain control pot with a control range of +/- 20 dB is on.

The Stereo Hi-Low Equalizer has two fixed bands with a control range of +/- 20 dB each. The frequency respone of these filters have been optimized for the use with an effect signal. Both filters are bell type filters. The Hi-EQ has a very low Q factor of approx. 0.5 and a center frequency of 10 kHz. The gain or attenuation remains almost constant in the range between 7 and 15 kHz. The Low-EQ has a slightly higher Q-factor of approx. 0.7. It's center frequency is 80 Hz. This allows an efficient control of the low frequency components of any effect signal without the risk of subsonic noise. The equalizer is bypassed unless the EQ switch is pressed

The Cue Send is fed pre solo logic, therefor, the cue signal is present even if the console is in solo mode and the solo logic of the return is switched on. The POST switch sets the cue send post fader and the pan switch puts the cue post the main balance pot. An additional CUT switch mutes the cue sends independently. The cue send is always driven by a stereo signal. The cue pan is always active und makes possible to set the position of the cue mix differently.

The main signal feeds the stereo fader via the solo circuitry. The solo system has a SOLO and an ON switch. It is normally inactive so that every signal on the stereo returns is not muted by solo. This version covers the principle of solo in place that is used with all the 5MT mixing consoles. Solo makes possible to hear a particular channel with the original level and pan and all its effects. If for some reason the effect signal is not supposed to be heard while solo is active or if an independent signal, like a stereo keyboard, is connected to the return, the solo logic can be activated by the ON switch. In this case, the return is muted by solo and it is also able to set the console into solo mode. This does not make any sense if the output of an effect unit, which is driven by aux sends, is assigned to the returns, since a solo would cut the input channels and their aux sends that feed the input of the effect device. The result of this constellation would be, that the solo system lets you just hear the output noise of the effect device.

The PFL switch routs the pre fader signal into the PFL bus and activated the PFL control bus.

The main fader is a stereo rotary pot that has no automation interface with the E2 Master. Automated effect return section are available with the AT Master Section and the Recall Master Section RMST of the 5MT MR Series. The Cut function is controlled by the local CUT switch and can be controlled by the two mute groups as well. Two switches select the mute groups A and B. Parallel selection of both groups is possible.

The multicolor Peak Present LED indicates a level of -20 dB with green color. The color turns to yellow at a level of 0 dB and changes its color via orange to red if the level increases above 0 dB. It reaches deep red color if the headroom is only 5 dB. The LED reads the peak level at the fader input.

A Balance Pot can be inserted by the BAL-ON switch. It controls the left and right channels contra-rotating with a center attenuation of 0 dB that is appropriate for the control of a stereo signal. The MIX switch routs the signal to the main mix bus. In addition, the 24 routing busses can be selected by the switches of the routing matrix. The left stereo channel of the returns is assigned to the odd busses, the right channel to the even numbered busses.