as well as to solo, and add to aux send 1 and 2. This is routed using the FW/line input selector [23] on channels 11 and 12. This is useful for live performances, where those 2 channels might have, for example, a software synthesizer you are triggering from a MIDI keyboard, and you want to treat the softsynth as "just another instrument," with equal processing and routing options as the hardware keyboards coming into the other channels.

The FireWire interface works with both PC (using ASIO for Windows XP and Vista) and Mac (Core Audio for Mac OS 10.4.11 or higher).

4. LEFT/RIGHT XLR MAIN OUTPUTS

These male XLR connectors provide a balanced line- level signal that represents the end of the mixer chain, where your fully mixed stereo signal enters the real world. Connect these to the inputs of your main power amplifiers, powered speakers, or serial effects processor (like a graphic equalizer or compressor/ limiter). It provides a fully balanced signal that is the same level as the 1/4" TRS main out jacks [13] on the top panel.

5. MAIN OUTPUT LEVEL

When this switch is out (+4 dB), the XLR main outputs [4] provide a "+4 dBu" line-level signal. You can then connect these outputs to the line-level inputs of power amplifiers, powered loudspeakers, or serial processors.

When the switch is pushed in (mic), the XLR main outputs are attenuated to microphone level. You can then connect these outputs safely to the microphone inputs of another mixer, providing a submix for keyboards or drums, for example, in a live sound application. The main outputs can then be plugged directly into a stage snake, and appear back at the front of house console like any other microphone level source.

When mic is engaged, you can safely plug the XLR main output into a mixer's microphone input, even if it provides 48 V phantom power.

The switch is recessed, to reduce the chance of accidently turning it on or off when plugging things in.

6. AUX SEND 1 and 2

These 1/4" TRS connectors allow you to send balanced or unbalanced line-level outputs to external effects devices, headphone amplifiers, or stage monitors. These could either be passive stage monitors powered by an external amplifier, or powered stage monitors with built-in power amplifiers.

12Onyx 1220i

Aux send 1 and aux send 2 are independent of each other, so you can set up two separate aux mixes.

The aux 1 send signal is the sum (mix) of all the channels whose aux 1 send control [29] is set to more than minimum. The aux 2 send is the sum of all the channels whose aux 2 send control is set to more than minimum. The overall aux output level can be adjusted with the aux send master controls [42].

The aux sends can either be pre or post fader, depending on the position of the pre/post switches [43]. For stage monitor work, use pre, so the stage monitors do not increase in volume when the channel faders are adjusted. Imagine how upsetting that can be to big hairy drummers. This allows you to set up the monitor mix and levels just right, and not have it change every time a channel fader is adjusted.

For external processors, use post. In this way, the feed to external processors will vary with the channel faders, so the level of any returned effect (like an echo) will also change if the channel fader is changed, keeping them in the same ratio (wet/dry).

7. AUX RETURN 1 and 2

These 1/4" TRS stereo input connectors allow you to add the stereo processed output from external effects processors or other devices to the main mix.

Level adjustment of the incoming signals is made with the aux return controls [44].

The signals going into aux return 2 can also be added to aux send 1 by engaging the return to aux 1 switch

[45].For example, you could add effects from an external effects processor to your stage monitors.

You can also use these inputs to add any stereo line- level signals to your main mix, so it could be another line-level source, not just an effects processor.

If you are connecting a mono source, use the left (mono) aux return input, and the mono signals will appear on both sides of the main mix.

8. INSERT (Ch. 1-4)

These unbalanced 1/4" jacks on channels 1-4, are for connecting serial effects processors such as compressors, equalizers, de-essers, or filters. The insert point is after the gain control [21] and low cut filter [19], but before the channel’s EQ and fader [33]. The channel signal can go out of the insert jack to an external device, be processed and come back in on the same insert jack. To do this requires a standard insert cable that must be wired thusly:

Tip = send (output to effects device)

Ring = return (input from effects device)

Sleeve = common ground