Инструкции Пользователя для Mackie ProFX4v2

Owner’

s Manual

In addition to accepting balanced mic or line-level 

signals using an XLR connector, ProFX4v2 mixers  
may also accept 1/4" line-level signals driven by  
balanced or unbalanced sources. These 1/4" jacks  
share circuitry (but not phantom power) with the  
mic preamps.

To connect balanced lines to these inputs, use  

a 1/4" Tip-Ring-Sleeve (TRS) plug. “TRS” stands for  
Tip-Ring-Sleeve, the three connection points available 
on a stereo 1/4" or balanced phone jack or plug.  

TRS jacks and plugs are used for balanced signals and 

stereo headphones and are wired as follows according 
to standards specified by the AES (Audio Engineering 
Society):

1/4" TRS Balanced Mono Wiring:
     Sleeve = Shield (ground) 
     Tip = Positive (+ or hot) 
     Ring = Negative (– or cold)

To connect an unbalanced line to this  input, use  

a 1⁄4" mono (TS) phone plug or  instrument cable.  
They are wired as follows, according to standards  
specified by the AES (Audio Engineering Society):

1/4" TS Unbalanced Mono Wiring:
     Sleeve = Shield (ground) 
     Tip = Positive (+ or hot)

The channel 1 line-level input may also accept 
instrument-level signals if the hi-z switch is 
engaged. This allows you to connect guitars 

directly into channel 1 without the need for a DI box.

The stereo line inputs are designed for 1/4" TRS   

balanced or 1/4" TS unbalanced signals. They may    
accept any line-level instrument, effects device, CD 
player, etc. 

If you are connecting a mono source, use the left 

(mono) input, and the mono signals will appear  
on both sides of the main mix.

ProFX4v2 mixers have a “U” symbol on almost every 

level control. It stands for “unity gain,” meaning no 
change in signal level. The labels on the controls  
are measured in decibels (dB), so you’ll know what 
you’re doing level-wise if you choose to change a  
control’s settings.

If you haven’t already, please read the "Getting 

Started" section on page 4. Setting the gain correctly 
will ensure that the preamplifier’s gain is not too high, 
where distortion could occur, and not too low, where  
the quieter, exquisitely-delicate passages might be lost 
in background noise.

The gain knobs adjust the input sensitivity of the mic 

and line inputs. This allows signals from the outside 
world to be adjusted to run through each channel at 
optimal internal operating levels.

For mono channels (mic input with  
a mono line input), the gain knob  
adjusts the input sensitivity of the  
mic and line inputs.

If the signal originates through the mic XLR jack, 

there will be 0 dB of gain with the knob fully down, 
ramping to 50 dB of gain fully up.

Through the 1⁄4" mono line inputs, there is 20 dB of  

attenuation fully down and 30 dB of gain fully up, with 
unity gain “U” at 12:00.

This 20 dB of  attenuation can be very handy when you 

are  inserting a hot signal, or when you want to add EQ 
gain, or both. Without this  “virtual pad,” there is more 
chance of channel clipping.

For stereo channels (no mic input)  
the gain control just affects the line-level 
inputs, with 20 dB of gain, and 20 dB  
of attenuation.