MIDI-controlled mute automation has been around for quite some time now, and the benefits are pretty well established. Even with a digital (or Dolby S analogue) multitrack, unwanted noise is bound to find its way onto tape from noisy sources, and the only practical way to eliminate this is to to gate it out or mute it. It is rarely practical to patch gates into every mixer channel, (though some top studio consoles provide exactly this facility), but a great many budget consoles now offer MIDI muting as a standard feature. Most MIDI muting systems are driven from an external sequencer using standard MIDI note data or, in the case of snapshot systems, MIDI program changes. Though the mutes have to be set manually in the first instance, so long as the sequencer is locked to tape via some kind of timecode system, the mute sequence will run correctly and accurately every time the mix is run through.

In general, such systems are very useful, not only for silencing open tracks during pauses in the programme material, but also for simple automation tricks such as switching a signal between two tracks with different EQ or aux send settings. While consoles with integral muting systems are now relatively cheap, there are still many serious mid-priced consoles around with no MIDI muting, which has created a market for third-party, add-on systems such as the LA Audio MIDI Mute under review.

Housed in a 1U rack, the MIDI Mute offers 32 channels of MIDI-driven muting, and is directly compatible with both pro and semi-pro systems running at -10dBV and +4dBu respectively. Connection to the individual mute channels is via stereo jacks, all located on the rear panel, and these may be connected directly to the insert points of a console or via a patchbay. You will, however, need to make up special cables, as the two cores need to be crossed over to make the right connections. The standard MIDI sockets &re also located on the rear panel.

FET soft switching is used to avoid switching clicks, and the system can either be controlled directly using note-on/note-off information or can store up to 128 internal snapshots, which can be selected using MIDI program changes. The internal memory is battery backed so that no data is lost between sessions, while up to four units may be linked to provide a maximum of 128 channels of muting.

PANEL GAME

Each mute channel has its own front panel button with red status LED, while additional buttons handle Undo, Play, and Edit. Further LEDs indicate the operational mode, these being labelled Patch, Mute Call, and MIDI. No self-respecting MIDI unit would be complete without a few dual-function buttons, but this is handled quite painlessly, with the alternate functions printed below the controls in yellow.

You can use the MIDI Mute with or without a sequencer. Without a sequencer, you can set up and then recall, using the Play button, a sequence of mutes. During mute operation, MIDI note data is present at the MIDI Out socket. Rather more useful is the normal Mute mode, in which the mute buttons are activated in real time, and the mute data stored in a suitable MIDI sequencer. Depending on the type of sequencer you're using, you can then edit the mute data with varying degrees of ease; playing back the sequence will cause the mutes to switch automatically, to the accompaniment of winking status LEDs. This is very easy and, to be quite honest, I wouldn't bother to work any other way.

Even so, Patch mode is available for those who prefer the snapshot way of working, where the on/off status of all 32 mutes constitutes one 'snapshot'. There are 128 snapshots available, which can be called up using MIDI program change messages, or directly from the front panel if manual operation is preferred. The manual method is less intuitive, as the patches are stored as four banks of 32; you therefore have to first select the bank, and then a number from 1-32 using the mute buttons.

Edit mode allows you to change the working MIDI channel, and to define the note range to which the unit responds (you choose the lowest note number, for channel 1, and the other channels are assigned consecutively and in ascending order). Patch banks can be dumped from one unit to another using MIDI, or can be dumped to a sequencer. To maintain your confidence in the unit, a self-test facility runs a set of diagnostics every time the unit is powered up.

SUMMARY

As MIDI mute units go, this one is pretty unexciting — which is a good thing, as the last thing you need from an ostensibly workmanlike machine like this is excitement. It is not for nothing that the Chinese curse their enemies with the phrase "May you live in interesting times". No, the LA MIDI Mute gets on with its job, while letting you get on with yours. The ease of editing (of mute data) is determined by the sequencer you choose to use with it, and with a little imagination, you can use the mutes very creatively. For example, in a 16-track studio, you could assign some of the mutes to the mixer channels handling the tape returns, while others could be accessed via the patchbay, providing the flexibility to mute subgroups, effects sends, effects returns and so forth. Indeed, this flexibility gives add-on units like this the edge over built-in systems.

Of course, sound quality is of vital importance, and I'm pleased to say that no audible noise was evident from the LA MIDI Mute, and the channels couldn't be driven into distortion at normal operating levels. Switching was quite free of clicks, even when several channels were switched simultaneously, and there were no operating problems or mysterious data losses. On a 'per channel' basis, this is one of the least expensive MIDI mute units around, yet it performs to a very high standard. The only drag is having to make up the necessary connecting leads to get it up and running, but after that it's all plain sailing, and I'm sure most users will find it a welcome addition to their studios.

Further information

LA Audio MIDI Mute £581.63 inc VAT.

LA Distribution, (Contact Details).