American Audio Mixer M1224FX User Manual

							
User Guide 
and Reference Manual
    6/08
M1224FX
6122 S. Eastern Ave
Los Angeles, CA 90040
www.AmericanAudio.us 
						

							
©American Audio®   -   www.americanaudio.us   -   M1224FX Instruction Manual Page 2
   M1224FX                                                       CONTENTS
  M1224FX                                                                Mai N  F EaTURES
MAIN FEATURES.........................................................................................................................\
...........2
ELECTRICAL  PRECAUTIONS.............................................................\
...................................................3
SAFETY  PRECAUTIONS.............................................................\
...........................................................5
INTRODUCTION....................................................................................................................................6
SET-UP  PRECAUTIONS.............................................................\
............................................................6
U NPAC kIN g.........................................................................................................................................7
qUICk  START........................................................................................................................................7
CONTROLS AND FUNCTIONS
  CHANNEL  CONTROL................................................................................................\
.................8
 MAIN  CONTROL.......................................................................................................................11
 INPUT  &  OUTPUT  CONNECTIONS.............................................................\
............................14                                                                         \
                                       
CO N N E C T O R S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6
HOME/STUDIO  RECORDINg  SET-UP........................................................................\
.........................18
LIVE  PERFORMANCE  SET  UP........................................................................\
.....................................19
EFFECTS LIST........................................................................\
..............................................................20
CLEANIN g......................................................................................................................22
TROU bLESHOOTIN g......................................................................................................................22
WARRANTY.........................................................................................................................................23
SPECIFICATIONS.....................................................................................................................24
• 4 Mono & 4 Stereo Channel Inputs
•  Stereo Main Outputs & ALT 3/4 Output 
•   3-band Eq, 1 Aux with Pre/Post Switch, 1 EFX,  bAL, Mute, & PFL for Stereo Input
•  Trim With Peak LED, HPF, 3-band Eq, 1 Aux With Pre/Post Switch, 1 EFX, Pan, Mute, & PFL     
 Switch for Mono Input
•  Trim With Peak LED, HPF (CH 5-8)
•   Main L/R With AFL Switch, ALT 3/4 With AFL, To Main Switch, AUX & EFX Send, AUX & EFX     
 Return
•  Tape With PFL Switch, HP/Control Room & Phantom Power
•   24-bit DSP Effect, 100 Presets, EFX On/Off & EFX Level
•   Tape With PFL Switch, HP/Control Room & Phantom Power
•   6 XLR Mic/Inputs
•   XLR & 1/4” Phone Jack  balanced & 1/4” Phone Jack for Mono Input
•  XLR & 1/4” Phone Jack For Stereo (Ch 5-8) & 1/4” Phone & Phono Jack For Stereo Input
•   1/4” Phone Jack For Stereo Return & Phono Jack For Tape In
•   1/4” Phone Jack For Main, ALT 3/4, Aux Send, EFX Send, Control Room & Headphone
•   Phono Jack For Tape & 1/4” Phone Jack For Footswitch 
						

							
©American Audio®   -   www.americanaudio.us   -   M1224FX Instruction Manual Page 3
NOTE:  This  product  satisfies  FCC 
regulations  when  shielded  cables 
and  connectors  are  used  to  con-
nect  the  unit  to  other  equipment. 
To  prevent  electromagnetic  inter-
ference  with  electrical  appliances 
such as radios and televisions, use 
shielded  cables  and  connectors 
for connections.
WARNINg: TO PREVENT FIRE OR ELECTRIC 
SHOCk  HAZARD,  DO  NOT  EXPOSE  THIS 
UNIT TO RAIN, LIqUIDS, OR MOISTURE 
CAUTION:  TO  PREVENT  ELECTRIC  SHOCk 
DO  NOT  USE  THIS  (POLARIZED)  PLUg 
WITH  AN  EXTENSION  CORD,  RECEPTACLE, 
OR  OTHER  TYPE  OF  ELECTRICAL  OUTLET 
UNLESS  THE  WIDE bLADES  CAN  bE 
CAREFULLY  INSERTED  INTO  A  MATCHINg 
WIDE SLOT.
ATTENTION:  POUR  PREVENIR  LES  CHOCS 
ELECTRI qUES  NE  PAS  UTILISER  CETTE 
FICHE  POLARISEE  AVEC  UN  PROLON-
gATEUR,  UNE  PRISE  DE  COURANT  OU 
UNE  AUTRE  SORTIE  DE  COURANT,  SAUF 
SI  LES  LAMES  PEUVENT  ETRE  INSEREES  A 
FOND SANS EN LAISSER AUCUNE PARTIE A 
DECOUVERT.
   M1224FX                                                ELECTRiCaL SaFETY PRECaUTiONS
The  serial  and  model  number  for  this  unit  is 
located  on  the  rear  panel.  Please  write  down 
the  numbers  here  and  retain  for  future  refer-
ence. 
Model No._____________________________
Serial No._____________________________
Purchase Notes:
Date of Purchase_______________________
Dealer Name__________________________
Dealer Address_________________________
_____________________________________
_____________________________________
Dealer Phone__________________________ 
						

							
ELECTRICAL PRECAUTIONS
RISK OF ELECTRIC SHOCKDO NOT OPEN
CAUTION
The exclamation point within an equilateral triangle isintended to alert the user to the presence of importantoperating and maintenance (servicing) instructions inthe literature accompanying the appliance.
The lightning flash with arrowhead symbol, within anequilateral triangle, is intended to alert the user to thepresence of uninsulated dangerous voltage within theproducts enclosure that may be of sufficient magnitudeto constitute a risk of electric shock to persons.
REad iNSTRUCTiONS — All the safety and operatinginstructions should be read before the product isoperated.RETaiN iNSTRUCTiONS — The safety and operatinginstructions should be retained for future reference.HEEd WaRNiNGS — All warnings on the product andin the operating instructions should be adhered to.FOLLOW iNSTRUCTiONS — All operating and useinstructions should be followed.CLEaNiNG — The product should be cleaned only witha polishing cloth or a soft dry cloth. Never clean withfurniture wax, benzine, insecticides or other volatileliquids since they may corrode the cabinet.aTTaCHMENTS — Do not use attachments notrecommended by the product manufacturer as theymay cause hazards.WaTER aNd MOiSTURE — Do not use this productnear water — for example, near a bathtub, washbowl, kitchen sink, or laundry tub; in a wet basement;or near a swimming pool; and the like.aCCESSORiES — Do not place this product on anunstable cart, stand, tripod, bracket, or table. Theproduct may fall, causing serious injury to a child oradult, and serious damage to the product. Use onlywith a cart, stand, tripod, bracket, or tablerecommended by the manufacturer, or sold withthe product. Any mounting of the product shouldfollow the manufacturer’s instructions, and shoulduse a mounting accessory recommended by themanufacturer.CaRT — A product and cart combination should bemoved with care. Quick stops, excessive force, anduneven surfaces may cause the product and cartcombination to overturn.
vENTiLaTiON — Slots and openings in the cabinet areprovided for ventilation and to ensure reliableoperation of the product and to protect it fromoverheating, and these openings must not beblocked or covered. The openings should never beblocked by placing the product on a bed, sofa, rug,or other similar surface. This product should not beplaced in a built-in installation such as a bookcase orrack unless proper ventilation is provided or themanufacturer’s instructions have been adhered to.POWER SOURCES — This product should be operatedonly from the type of power source indicated on themarking label. If you are not sure of the type ofpower supply to your home, consult your productdealer or local power company.LOCaTiON – The appliance should be installed in astable location.NONUSE PERiOdS – The power cord of the applianceshould be unplugged from the outlet when left un-used for a long period of time.
GROUNdiNG OR POLaRiZaTiON•If this product is equipped with a polarized alternatingcurrent line plug (a plug having one blade wider thanthe other), it will fit into the outlet only one way. Thisis a safety feature. If you are unable to insert the plugfully into the outlet, try reversing the plug. If the plugshould still fail to fit, contact your electrician toreplace your obsolete outlet. Do not defeat thesafety purpose of the polarized plug.•If this product is equipped with a three-wiregrounding type plug, a plug having a third (grounding)pin, it will only fit into a grounding type power outlet.This is a safety feature. If you are unable to insert theplug into the outlet, contact your electrician toreplace your obsolete outlet. Do not defeat thesafety purpose of the grounding type plug.POWER-CORd PROTECTiON - Power-supply cordsshould be routed so that they are not likely to bewalked on or pinched by items placed upon oragainst them, paying particular attention to cords atplugs, convenience receptacles, and the point wherethey exit from the product.OUTdOOR aNTENNa GROUNdiNG — If an outsideantenna or cable system is connected to the product,be sure the antenna or cable system is grounded soas to provide some protection against voltage surgesand built-up static charges. Article 810 of the NationalElectrical Code, ANSI/NFPA 70, provides informationwith regard to proper grounding of the mast andsupporting structure, grounding of the lead-in wireto an antenna discharge unit, size of groundingconductors, location of antenna-discharge unit,c o n n e c t i o n t o g r o u n d i n g e l e c t r o d e s , a n drequirements for the grounding electrode. See FigureA.LiGHTNiNG — For added protection for this productduring a lightning storm, or when it is left unattendedand unused for long periods of time, unplug it fromthe wall outlet and disconnect the antenna or cablesystem. This will prevent damage to the productdue to lightning and power-line surges.POWER LiNES — An outside antenna system shouldnot be located in the vicinity of overhead power linesor other electric light or power circuits, or where itcan fall into such power lines or circuits. Wheninstalling an outside antenna system, extreme careshould be taken to keep from touching such powerlines or circuits as contact with them might be fatal.OvERLOadiNG — Do not overload wall outlets,extension cords, or integral convenience receptaclesas this can result in a risk of fire or electric shock.
OBJECT aNd LiQUid ENTRY - Never push objects ofany kind into this product through openings as theymay touch dangerous voltage points or short-outparts that could result in a fire or electric shock.Never spill liquid of any kind on the product.SERviCiNG — Do not attempt to service this productyourself as opening or removing covers may exposeyou to dangerous voltage or other hazards. Refer allservicing to qualified service personnel.daMaGE REQUiRiNG SERviCE  - Unplug this productfrom the wall outlet and refer servicing to qualifiedservice personnel under the following conditions:• When the power-supply cord or plug is damaged.•If liquid has been spilled, or objects have fallen intothe product.•If the product has been exposed to rain or water.•If the product does not operate normally by followingthe operating instructions. Adjust only those controlsthat are covered by the operating instructions as animproper adjustment of other controls may result indamage and will often require extensive work by aqualified technician to restore the product to itsnormal operation.•If the product has been dropped or damaged in anyway.• When the product exhibits a distinct change inperformance — this indicates a need for service.REPLaCEMENT PaRTS -- When replacement partsare required, be sure the service technician has usedreplacement parts specified by the manufacturer orhave the same characteristics as the original part.Unauthorized substitutions may result in fire, electricshock, or other hazards.SaFETY CHECk - Upon completion of any service orrepairs to this product, ask the service technician toperform safety checks to determine that the productis in proper operating condition.WaLL OR CEiLiNG MOUNTiNG — The product shouldnot be mounted to a wall or ceiling.HEaT — The product should be situated away from heatsources such as radiators, heat registers, stoves, orother products (including amplifiers) that produceheat.
IMPORTANT SAFETY INSTRUCTIONS
ANTENNALEAD INWIRE
GROUNDCLAMP
ANTENNADISCHARGE UNIT(NEC SECTION 810-20)
GROUNDING CONDUCTORS(NEC SECTION 810-21)
GROUND CLAMPS
POWER SERVICE GROUNDINGELECTRODE SYSTEM(NEC ART 250, PART H)
ELECTRICSERVICEEQUIPMENT
Fig. A
NEC — NATIONAL ELECTRICAL CODE
C A U T I O N : T O R E D U C E T H E R I S K O F E L E C T R I C SHOCK, DO NOT REMOVE THE COVER (OR BACK). T H E R E A R E N O U S E R S E R V I C E A B L E P A R T S INSIDE  REFER SERVICE TO YOUR AUTHORIZED AMERICAN AUDIO® SERVICE TECHNICIAN.
   M1224FX                                               ELECTRiCaL SaFETY PRECaUTiONS
©American Audio®   -   www.americanaudio.us   -   M1224FX Instruction Manual Page 4 
						

							
©American Audio®   -   www.americanaudio.us   -   M1224FX Instruction Manual Page 5
1. For  adult  use  only  -  keep  out  of  the  reach 
of   children.
2. Water and Moisture - The player should not 
be  used  near  water  -  for  example,  near  a  bath 
tub,  kitchen  sink,  laundry  tub,  in  a  wet base-
ment  or  near  a  swimming  pool,  etc. Do  not 
spill  water  or  other  liquids  in  to  or  on  to  your 
mixer.
3. Ventilation  -  The  Mixer  should  be  situated 
so  that  its  location  or  position  does  not  inter-
fere  with  its  proper  ventilation.  For example, 
the  Mixer  should  not  be  situated  on  a  bed, 
sofa, rug, or similar surface that may block the 
ventilation  openings;  or,  placed  in  a  built-in 
installation, such as a bookcase or cabinet that 
may impede the flow of air through the ventila-
tion openings. 
4. Heat  -  The  Mixer  should  be  situated  away 
from heat sources such as radiators, heat reg-
isters,  stoves,  or  other  appliances  (including 
amplifiers) that produce heat.
5. Power Sources - The Mixer should be con-
nected  to  a  power  supply  (wall  outlet) only  of 
the type described in the operating instructions 
or as marked on the Mixer.
6. Servicing  -The  user  should  not  attempt  to 
service the Mixer beyond that described in the 
operating  instructions. There  are  no  user  ser-
viceable parts inside. All other servicing should 
be  referred  to  qualified  service  personnel.  The 
Player  should  be  serviced  by  qualified  service 
personnel when:
 A.  The power-supply cord or the plug has   
  been damaged.
 b. Objects have fallen, or liquid has been    
  spilled into the Mixer.
 C. The Mixer has been exposed to rain   
  or water.
     D. The Mixer does not appear to operate   
  normally or exhibits a marked change  
  in performance.
7. Never  disassemble  or  modify  your  unit  in 
any way, doing so will void your manufactures 
warranty.
   M1224FX                                                SaFETY PRECaUTiONS
8. Never plug this mixer in to a dimmer pack.
9. Do not let insecticides, benzene, or thinner 
come in contact with the surface of the  
unit.
10. This unit is intended for indoor use only, use 
of this product outdoors voids all warranties.
11. Always  mount  this  unit  in  safe  and  stable 
matter.
12. Disconnect from main power before making 
any type of connection.
13. Cleaning - The  mixer should be cleaned 
only as recommended by the manufacturer. 
Use a soft cloth to wipe down the outside of the 
unit. For stubborn stains moisten a soft cloth 
with  glass cleaner or other mild detergent to 
wipe away any stains. Use a soft cloth to wipe 
any residual cleaner. Never use volatile clean-
ers  such as benzene, solvent, or thinner to clean 
your unit, these cleaners will damage the units 
surface. 
14.  Handle the power supply cord carefully. Do 
not  damage  or  deform;  it  may  cause  electric 
shock  or  malfunction  when  used.  Hold  plug 
attachment  when  removing  from  wall  outlet. 
Do not pull on the cord.
15.  To  avoid  electric  shock,  do  not  open  the 
top cover when the unit is plugged in. If prob-
lems occur with the unit, call American Audio® 
customer support.
16.  Do not place metal objects or spill any liq-
uids    inside  or  on  the  mixer.  Electric  shock  or 
malfunction may occur.
17.  Power  Cord  Protection  -  Power  supply 
cords  should  be  routed  so  that  they  are  not 
likely  to  be  walked  on  or  pinched  by  items 
placed upon or against them, paying particular 
attention to cords at plugs, convenience recep-
tacles,  and  the  point  where  they  exit  from  the 
mixer. Route your power cord out of the way of 
foot traffic.
18. Always  have  the  trim  controls  set  to  their 
lowest  level  during  initial  power-up  to  prevent 
speaker damage. 
						

							
Introductions: Congratulations and thank you for purchasing the American Audio® M1224FX mixing 
console. This mixing console is a representation of American Audio’s continuing commitment to pro-
duce  the  best  and  highest  quality  audio  products  possible  at  an  affordable  price.  Please  read  and 
understand this manual completely before attempting to operate your new mixer. Please carefully read 
and understand the instructions in this manual thoroughly before attempting to operate this unit. These 
instructions contain important safety information regarding the use and maintenance of this unit. Take 
special care to follow all warning symbols and labels both on the unit and printed in this manual. Also, 
Please keep this manual with the unit, for future reference.
Customer Support: 
American  Audio®  provides  a  toll  free  customer  support  line,  to  provide  set  up  help  and  answer  any 
question should you encounter problems during your initial set up or operation. You may also visit us 
on the web at www.americanaudio.us for any comments or suggestions. Service Hours are Monday 
through Friday 9:00 a.m. to 5:30 p.m. Pacific Standard Time.
 Voice:    (800) 322-6337
 Fax:    (323) 582-2941
 E-mail:   [email protected]
To purchase parts online visit http://parts.americandj.com
Caution!  There  are  no  user  serviceable  parts  inside  this  mixer.  Do  not  attempt  any  repairs  yourself, 
without being instructed to do so by an authorized American Audio service technician. Doing so will 
void your manufactures warranty. In the unlikely event your mixer may require service, please contact 
American Audio® customer support.
Do not discard the packing carton in the trash. Please recycle when ever possible.
  M1224FX                                                                                  iNTROdUCT iON
©American Audio®   -   www.americanaudio.us   -   M1224FX Instruction Manual Page 6
  M1224FX                                 SET -UP  P REC aUT iONS
Please be sure to make any connections before plugging the mixer in to an electrical outlet. All fader 
and volume controls should be set to zero or minimum position, before the mixer is switched on. If the 
mixer has been exposed to drastic temperature fluctuation (e.g. after transportation), do not switch on 
the mixer immediately. The arising condensation of water might damage your device. Leave the device 
switched off until it has reached room temperature.
Operating Determinations:
•  When installing this mixer, please make sure that the device is not exposed or will not be 
 exposed to extreme heat, moisture or dust!
• Do not operate the mixer in extremely hot (more than 30°/100°F) or extremely cold (less than 
 5°C/40°F) surroundings. 
•  keep the unit out of direct sunlight and away from heaters.
• Operate the mixer only after becoming familiar with its functions. Do no\
t permit operation by 
 persons not qualified for operating the mixer. Most damages are the result of unprofessional 
 operation!
• Do not attempt to operate this mixer if the power cord has been frayed or damaged. 
• Disconnect from main power before making any type of connection.
• Do not attempt to operate this mixer, if it becomes damaged in any way.
• Never operate this mixer when it’s covers are removed.
• To reduce the risk of electrical shock or fire, do not expose this mixer to rain or moisture.
• This mixer is intended for indoor use only, use of this product outdoors voids all warranties.
• During long periods of non-use, disconnect the mixer’s main power. 
						

							
©American Audio®   -   www.americanaudio.us   -   M1224FX Instruction Manual Page 7
  M1224FX                                                      FRONT  &  R Ea R  P aNEL
  M1224FX                                                                  UNPaCki NG
Every  M1224FX  has  been  thoroughly  tested  and  has  been  shipped  in  perfect  operating  condition. 
Carefully check the shipping carton for damage that may have occurred during shipping. If the carton 
appears to be damaged, carefully inspect your mixer for any damage and be sure all equipment neces-
sary to operate the mixer has arrived intact. In the event damage has been found or parts are missing, 
please contact our toll free customer support number for further instructions. Please do not return the 
mixer to your dealer without first contacting customer support. 
						

							
  M1224FX                      CH aNNEL  CONTROLS  aNd  FUNCT iONS
©American Audio®   -   www.americanaudio.us   -   M1224FX Instruction Manual Page 8
4
3
1
7
6
5
9
8
2
10
CHANNEL CONTROL SECTION
MONOMONO/STEREO 
COMbO
STEREO 
						

							
CHANNEL CONTROL SECTION:
1.   PEAK LED INDICATORS & TRIm C ONTROL -  
PEAK INDICATORS - These LED indicators will “light” when the input signal reaches 5d b below the 
channel’s  clipping  point.  If  the  LED  “lights”  more  then  usual,  you  should  use  the TRIM  CONTROL  to 
decrease the input level of the channel. If this does not work, reduce the output level of the connected 
source.
TRIm CONTROL - This adjustment is used to adjust the audio source signal input gain for a channel. 
The best S/N and dynamic range balance will be reached if you adjust the TRIM CONTROL so that the 
PEA k INDICATORS “light” occasionally. 
Channel Sensitivity”
  MIC input sensitivity is between +6d b and -50db. 
  Line input sensitivity is between +14d b and -30db.
  The Mono/Stereo Combo input channel sensitivity is between +20d b and -20db.
2.  HPF (HIGH PASS FILTER) BUTTON - This button toggles the HPF (Hight Pass Filter) on or off. To 
turn the HPF on press the button in. The HPF cuts frequencies  below 75Hz.
3. EQUALIZER - Please see the chart below for the max. Boost/Cut for each control. 
   CHANNEL H IGH CONTROL - This knob is used to adjust the high (treble) frequency levels of the channel. 
Turning the knob in a counter-clockwise direction will decrease the amount of treble applied to a channel 
signal, turning the knob in a clockwise direction will increase the amount of treble applied to a channel signal.
    CHANNEL mID  CONTROL - This knob is used to adjust the midrange levels of the channel. Turning 
the knob in a counter-clockwise direction will decrease the amount of midrange applied to a channel 
signal,  turning  the  knob  in  a  clockwise  direction  will  increase  the  amount  of  midrange  applied  to  a 
channel signal.
      CHANNEL  LOw  CONTROL - This  knob  is  used  to  adjust  the  low  frequency  levels  of  the  chan-
nel. Turning the knob in a counter-clockwise direction will decrease the amount of bass applied to a 
channel signal, turning the knob in a clockwise direction will increase the amount of bass applied to a 
channel signal.
4. AUX CONTROLS - The AUX knobs control the signal level that the channel sends to AUX bus. 
5. PRE/POST BUTTON - This button determines if the AUX signal is Pre Fader (signal level is not 
affected by fader position) or Post Fader (signnal level is affected by the fader position). 
6.  EFX CONTROL - These knobs control the signal levels sent to the EFX bus. The channel signals 
mixed by this bus have their overall level set by the MASTER EFX SEND control to the EFX jack located 
on the front top panel. Since the control is place after the channel fader, the signal level will be 
affected by the channel fader’s setting.
NOTE: The Effect bus signal is also fed into the internal DSP (digital signal processor).
  M1224FX                 CHaNNEL  CONTROLS  aNd  FUNCT iONS  cont.
©American Audio®   -   www.americanaudio.us   -   M1224FX Instruction Manual Page 9
CONTROLMAX.
BOOST/CUTFREQUENCYTYPE
HIGH±15dB12kHzShelving
MID±12dB2.5kHzPeaking
LOW±15dB80HzShelving 
						

							
©American Audio®   -   www.americanaudio.us   -   M1224FX Instruction Manual Page 10
7. PAN/BALANCE CONTROL - 
PAN (mono Control) - This control pans the channel signal across the master L and R buses, there-
fore determining the ideal position of the sound from that channel.
EXA mPLE:  If  the  PAN  control  is  set  all  the  way  to  the  left,  the  sound  from  that  channel  will  only  be 
projected from the left speaker only. Same goes for the control being set all the way to the right, only 
from the right speaker.
BALANCE (Stereo Control) - This control lets you adjust the balance of the L/R position, of the stereo 
input signal. Turning this knob to the left moves the source signal towards the MAIN MIX L bus, turning 
the knob to the right sends the signal towards the MAIN MIX R bus.
8.  mUTE/ALT  3/4  BUTTON  - When  the  corresponding  channels  MUTE/ALT  3/4  button  is  not  active 
(depressed) the channel output will be sent to the ALT 3/4 output, and not the MAIN L/R output. The 
ALT 3/4 bus gives you a second independent stereo sub mix with its own sub master stereo fader.
9.  PFL  BUTTONS  - This  button  allows  you  to  monitor  the  PRE  FADER  LEVEL  input  signal  through 
headphones or the control room outputs. When the button is NOT pressed the channel signal will be 
sent to the PFL bus.   
10.  CHANNEL  FADERS  - Thes  faders  are  channel’s  main  level  control.  These  fader’s  control  the 
signal level sent from the channel to the master mixing, group outs, and effect buses. The settings of 
the input channel faders affect the mix or the sound level balance between the instruments or other 
sources  connected  to  the  inputs.  When  a  channel  is  not  being  used,  the  fader  should  be  set  at  the 
minimum position to prevent any unwanted noise added to the main signal. 
  M1224FX                 CHaNNEL  CONTROLS  aNd  FUNCT iONS  cont.