Stereo Line Inputs (Ch. 5-12); Ctrl-Rm Out; Left/Right 1/4" Main Outputs; Alt 3-4 Out - Mackie ONYX 1220i Owner's Manual

To connect unbalanced lines to these inputs, use a
1⁄4" mono (TS) phone plug, wired as follows:
Tip = Positive (+ or hot)
Sleeve = Shield or ground
The line-level inputs of channels 1 and 2 can also
accept instrument-level signals if the hi-z switches
[18] are pressed in. This allows you to connect guitars
directly to channels 1 and 2, without the need for a DI
box. The input impedance is optimized for direct con-
nection, and high-frequency fidelity is assured.

11. STEREO LINE INPUTS (Ch. 5-12)

These 1/4" jacks can be driven by balanced or unbal-
anced sources.
To connect balanced lines to these inputs, use a 1⁄4"
Tip-Ring-Sleeve (TRS) plug, wired as follows:
Tip = Positive (+ or hot)
Ring = Negative (– or cold)
Sleeve = Shield or ground
To connect unbalanced lines to these inputs, use a
1⁄4" mono (TS) phone plug, wired as follows:
Tip = Positive (+ or hot)
Sleeve = Shield or ground
If you just have a mono source, plug it into the left
input (labeled left/mono), and the signal will appear
(as if by magic) equally on the left and right of the main
mix.

12. CTRL-RM OUT

These 1/4" TRS jacks provide balanced left and right-
line-level outputs to run studio monitors in the control
room. Connect these outputs to the inputs of an ampli-
fier, powered speakers, or recording device.
The source that plays in the control room, head-
phones, and meters can be selected using the switches
[35, 36] in the control room/phones source matrix:
• The main mix, if main mix is selected as the
control room/phones source
• Tape outputs, if tape is selected
• Alt 3-4 outputs if alt 3-4 is selected
• A 2-track FireWire feed from your computer if
FW 1-2 is selected
• A combination of all four above
Except for main mix, whatever is playing in these out-
puts can also be routed to the main mix if assign to main
mix [37] is engaged. (The main mix input to the control
room is disconnected if assign to main mix is engaged.)
The headphones and meters play the same program
as the control room. The meters show the levels prior to
the control room and phones level controls.
14 Onyx 1220i

13. LEFT/RIGHT 1/4" MAIN OUTPUTS

These 1/4" TRS output connectors provide the bal-
anced or unbalanced line-level output of the main mix
to an anxiously-waiting world. This is the same signal
that appears at the XLR main outputs [4] on the rear
panel, except it is not affected by the main output level
switch [5].
Connect these outputs to the next device in the signal
chain, such as an external processor (graphic equalizer
or compressor/limiter), external power amplifiers run-
ning passive loudspeakers, or to the inputs of powered
loudspeakers. They could also be connected to the
inputs of a balanced 2-track recorder, when doing a "live
to 2-track" type recording.
14. ALT 3–4 OUT
These 1/4" TRS jacks provide a balanced line-level sig-
nal that can provide an alternate stereo mix for record-
ing or subgrouping. Connect these outputs to the inputs
of an amplifier, powered speaker, or recording device.
Any channel whose mute switch [31] is engaged, is
added to the alt 3-4 outputs.
The alt 3-4 output doesn't have a master level control.
All channels assigned to the alt 3-4 bus are summed
together (post-fader and pan) and sent directly to the

alt 3-4 out.