Mackie 1220I User Manual

14

   Onyx 1220i

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 
connection, and high-frequency fi delity is assured.

These 1/4" jacks can be driven by balanced or  

unbalanced 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.

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  
amplifi er, powered speakers, or recording device.

The source that plays in the control room,  

headphones, 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  

outputs 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.

These 1/4" TRS output connectors provide the    

balanced 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 amplifi ers 
running 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. 

These 1/4" TRS jacks provide a balanced line-level  

signal that can provide an alternate stereo mix for 
recording or subgrouping. Connect these outputs to the 
inputs of an amplifi er, 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.