Electro-Voice Mixer Amplifier MA-1206 User manual

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
User Manual
MA-1206/MA-1212
Professional Mixer/Amplifiers

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Table of Contents
Typical Connections ............................................................................... 3
Features ................................................................................................. 2
Description ............................................................................................. 2
Installation .............................................................................................. 3
Grounding .................................................................................. 3
Ventilation .................................................................................. 3
Key Input Connections ............................................................... 3
Typical Connectons ................................................................... 4
Output Connections ................................................................... 6
Hig Impedance/Constant-Voltage Systems .............................. 7
Operation ................................................................................................ 8
Front Panel Controls .................................................................. 8
Rear Panel Controls and Connections ....................................... 9
Appendix A: Limited Warranty .............................................................. 13
Exclusions and Limitations....................................................... 13
Obtaining Warranty Service ..................................................... 13
Ot er Rig ts ............................................................................ 13
Appendix B: Safety Guidelines ............................................................. 14
AC Power Supply..................................................................... 14
DC Power Supply .................................................................... 14
Safety Precautions................................................................... 14
Tec nical Specifications ....................................................................... 16

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Page 2
Features
•Level controls for each input and a master volume control.
•Individual bass and treble tone controls.
•Automatic muting circuit with threshold adjustment.
•600 ohm transformer-isolated line input for paging, with
automatic muting of all other inputs.
•Low distortion.
•Output protection circuit.
•Au iliary line level inputs with internal mi ing for stereo source.
•Balanced line level output.
•Insertion point between preamp and amplifier.
•Phantom power on all microphone inputs enables microphones
to be used without separate power supplies.
Description
The Electro-Voice MA series of mi er-amplifiers are available with output
power ratings of 60 (MA-1206) or 120 (MA-1212) watts. The MA series
products provide background music and allow paging in environments
such as churches, small businesses, and professional offices.
The MA inputs include 10 combination balanced or unbalanced
Microphone/AUX level connections, 2 stereo AUX summing inputs,
telephone paging and Power Amp In connections. Inputs to Mic 1 can
be set to automatically mute the other Mic and AUX level input channels.
Input sources to Au 1 and 2 may include: tape players, compact-disc
players, AM/FM tuners, mi er-preamplifiers or wireless microphones.
The telephone paging input accepts the signal from a standard 600 ohm
paging line.
The Power Amp In jack, along with the Preamp Out jack, is provided to
insert an equalizer or other signal processing device before the power
amplifier.
The amplifier includes protection circuitry to prevent damage from either
open or shorted speaker lines.
An adjustable automatic muting circuit mutes all other inputs when the
paging input is activated.

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Page 3
Installation
To avoid hum in the output, be certain that all input cables are physically
separated from power wiring and transformers. Speaker cables should
also be kept away from input cables and power cables.
An e ample of what sources and output devices would be connected to
this unit is shown in Figure 1.
Grounding
Ground the chassis of the unit by using the ground terminal located on
the back panel. For the best grounding, connect the amplifier to an earth
ground such as a cold water pipe or ground rod. If additional equipment
is installed along with the amplifier, make sure their chassis are
connected together to reduce noise and hum.
Ventilation
To remove the heat generated by the power amplifier, provide ample
ventilation around the unit. Avoid blocking or impeding the vent slots in
the cabinet.
Locate the unit where it is free from direct sunlight, humidity, dust and
vibration.
Key Input Connections
Microphones. The Mic inputs are for use with balanced Low Impedance
(appro imately 200 ohms) or unbalanced high impedance
(appro imately 20k ohms) microphones. For high impedance
microphones, cables should be as short as possible in order to avoid
loss of High Frequency response. The results will vary with the
microphone and cable capacitance. However, a limit of 30 feet is
recommended.
The Mic inputs may be accessed by either XLR connectors or ¼ phone
plugs.
Figure 2 shows the wiring configurations of both unbalanced and
balanced microphones using either ¼ or XLR type connectors.

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Page 4
Typical Connections
Figure 1:
Typical Connections

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Figure 2:
XLR and Jack Inputs
Figure 2 shows the wiring configurations of both unbalanced and
balanced microphones using either ¼ or XLR type connectors.
Phantom Power: Phantom power allows the use of microphones without
separate power supplies on the Mic inputs. When phantom power is on,
24 V dc is produced at pins 2 and 3 on the Mic inputs. To enable
phantom power simply move the selector switch to the 24v position
above the desired input connector.
Microphone auto muting input: When a microphone or other source is
connected to input 1 and the front panel mute switch in the on position,
advance the threshold control to the point where the typical voice, and
not noise in the room, will operate the mute circuit. The microphones on/
off switch may be on, with the actual voice announcement triggering the
mute. If you want to defeat the muting function, place the mute switch in
the off (defeat) position.
Au iliary 1 and 2: High-level unbalanced sources may be connected to
the Au 1 and 2 jacks on the back panel.
Appropriate sources include a tape player, compact-disc player, AM/FM
tuner, mi er-preamplifier, wireless microphone or turntable equipped with
a ceramic or crystal cartridge. Use a single-conductor shielded cable.
Turntables usually have a separate ground wire. Connect this wire to the
ground terminal on the back panel to minimize hum.
Page 5

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Page 6
The set of RCA jacks (R and L) provided on the AUX 1 and 2 inputs are
designed to match to the two outputs of the typical stereo source. The
jacks are in parallel through internal series resistors and mi both
channels. The series resistors are chosen to avoid undesirable loading
effects on the output stage of typical stereo sources.
Plug monaural high-level unbalanced sources into either the R or L
jacks.
Paging: The voice paging signal from a 600 ohm balanced audio paging
line (such as a PBX system) may be connected to the au paging input
on the back panel.
Power Amp In: The Power Amp In jack provides direct access to the
power amplifier. It requires a line- level signal fed through a RCA type
phono plug wired with a single-conductor shielded cable.
Output Connections
The amplifier-can accommodate both Low Impedance and high
impedance constant-voltage speaker loads (25, 70.7, and 100 volt lines).
There are several considerations in the connection of a speaker or
multiple speakers to an amplifier:
1. Matching speaker impedance to the amplifiers rated Impedance: In
general, power amplifiers deliver rated power into a rated load
impedance. Lower impedances reduce the ma imum available power
available at rated distortion. Significantly lower impedances may cause
the amplifiers protection fuses to open, especially at high volume levels.
These low impedances should be avoided.
2. Power loss in speaker wire: The impedance of the speaker connecting
wire would ideally be zero, so all of the amplifier output power can be
delivered to the speaker load. However, the impedance of a longer
speaker wire installation can become a significant proportion of the total
impedance. Thus, part of the amplifier power is lost in the wire and the
power to the load is reduced. Wire impedance is highest for the longest
wire runs and smallest wire sizes.
Table 1 shows the two wire cable (copper) lengths permissible for a
number of wire sizes and speaker impedances to avoid a loss of more
than 0.5 dB. For a 1 dB loss (basically imperceptible), double the wire
lengths. For a 2 dB loss, multiply the lengths by 4.4.
In general, note that high load impedances allow the use of longer,
smaller gauge wiring.

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
3. Balancing relative speaker levels: There is no easy, electrically
efficient way to balance and adjust the sound levels among multiple
speakers in a low impedance installation. Constant-voltage high
impedance systems ease this process because they typically employ
speakers equipped with transformers with multiple input taps marked in
watts.
Low Impedance Speakers. The low impedance ohm output terminal is
provided for direct connection of one or more standard low impedance
speaker systems. For e ample, connect a single speaker system to the
common and 4 ohm terminals. Correct connection of several low
impedance speakers must follow the rules of proper series and parallel
impedance summation.
High Impedance/Constant-Voltage Systems
Installations that require high impedance speaker loads permit smaller
diameter wire for a given power loss in the speaker lines. Usually, low
impedance speakers are still used in such systems, but transformers are
used at the speaker locations to increase the impedance to the desired
value. Multiple transformer taps, labeled in watts, permit easy adjustment
of the individual speaker levels. Use simple parallel connection of the
transformer primaries (inputs). This eliminates the determination of load
impedance and series-parallel speaker connections.
For proper operation, all speakers should have transformers with the
same voltage rating, i.e. 25, 70.7, or 100 volts. The total of all the power
taps should be equal to or less than the amplifiers rated output power.
When the total equals the rated power, the amplifier may deliver rated
power to the load, depending on the input signal levels. Totals less than
the rated amplifier output will not damage the amplifier since the
resultant load impedance is higher than the amplifiers rated impedance
and thus only reduces the power delivered at ma imum amplifier level.
How ever, avoid power totals greater than rated amplifier power, since
the total load impedance drops below the amplifiers rated load.
Preamp Out: The Preamp Out jack provides a line-level mi of the input
signals, fed through a 1/4 inch phone plug wired with a single-conductor
shielded cable.
Use the signal at the Preamp Out jack to feed an e ternal equalizer or
signal processor whose output would connect to the Power Amp In jack.
Page 7

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Page 8
The preamplifier output may also be used alone to drive an additional
e ternal power amplifier with its own set of speakers. When the Preamp
Out jack is used, the mi ed signal to the internal power amplifier is
interrupted.
The balanced line level XLR output connector is ideal for feeding an
e ternal recording device or assistive listening system. When the rear
panel switch is in the fi ed position, the master volume control does not
affect the level at this line out jack, which permits setting the tape
recorders input level independent of system volume. The tape output is
buffered, so that an improper load will not affect system performance.
Operation
Figure 3:
Front Panel Layout
Front Panel Controls
(Refer to Figure 3)
1. Mute function switch: This switch lets you turn the Voice
Priority or page ducking function on or off of input 1 (1).
2. Au iliary 1&2 : These controls adjust the level of the two stereo
summing au iliary inputs. Input 1-10: These controls adjust the
levels of the 10 multi-use inputs.
3. Music signal monitor output level control: This control is a
screwdriver adjustment and lets you individually set the volume
of a headphone that is connected to the MONITOR OUTPUT
(4) or a small speaker connected to the 1w 8 ohm terminals on
the rear panel (25). Turning the control clockwise increases the
volume of the corresponding source.

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Page 9
Front Panel Controls (cont )
5. Overload indicator light: When the amplifiers output overloads
the OVER LOAD indicator illuminates and interrupts the output
signal. The output will resume when the volume is lowered or
the offending load is remove from the output line.
6. Power Switch and Power Indicator: This switch supplies power
to the unit. The power indicator lights when power is applied to
the unit.
7. Master: This control adjusts the level of the combined input
signals to the power amplifier.
8. Treble: This control adjusts the high frequency response by
providing up to 7 dB of boost or 12 dB of cut at 10 kHz.
9. Bass: This control adjusts the low frequency response by
providing up to 7 dB of boost or 12 dB of cut at 100 Hz.
Rear Panel Controls and Connections
(Refer to Figure 4)
10. Main cord connector: This connector is for the connection of the
supplied AC line cord.
11. AC fuse: The fuse can only be changed, in the event of a fault or
changing the supply voltage. This service should only be done by
an EV service center.
12. GND screw: In case the main outlet does not provide a ground
conductor, this screw offers the possibility to ground the amplifi-
ers metal parts.
Figure 4:
Rear Panel Layout

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Rear Panel Controls and Connections (cont )
13. Terminals for the DC battery supply: These two terminals allow
the connection of an e ternal 24V DC power supply such as a
24V battery. Operation of the amplifier is maintained even during
a power outage, since it is automatically switched to the DC
power source.
14. Output terminals: All speaker connections are made here. 25v/
70v/100v and low impedance speaker connections are sup-
ported. For additional information on constant voltage and low
impedance speaker hookups see section 4 Output Connec-
tions.
15. PRE OUT terminal: This terminal output provides the mi ed
audio signals of all sources that are connected to the amplifier
and can be utilized to feed an e ternal power amplifier, a signal
processor or any other e ternal appliance. The unbalanced signal
is affected by the individual input controls. Before using the PRE
OUT you have to remove the bridging-strip between this binding
post and the MAIN IN terminal (16).
16. MAIN IN terminal: After removing bridging-strip between the
PRE OUT and the MAIN IN terminals you can include an
e ternal signal processor in the audio-chain between the pre-
amplifier and the power output stage of the power amplifier.
17. AUX 1 and AUX 2 inputs: These two RCA-type connectors let
you connect the two channels of an e ternal high-level unbal-
anced signal source. Such as an AM/FM tuner, a cassette deck,
a CD player, etc.. An input level switch(20) is provided to properly
balance the input sensitivity with a variety of sources.
18. INPUT 1- 10 jacks: These ten balanced/unbalanced combination
type jack (XLR and 6.3mm) inputs are meant for the connection
of-condenser type microphones that accepts 24V phantom
power, dynamic microphones (30-600ohms) or a high level sound
sources (e.g AM/FM tuner, cassette deck, CD player, etc.)
Note: Connecting unbalanced microphones to the appliance when the
phantom is switched on could lead to severe damage to the
microphones and is therefore not advisable. It is absolutely
mandatory to only plug or unplug a microphone cable with the
phantom power turned off. Also make sure that the phantom
power is turned off when utilizing microphones that are not meant
to be operated with phantom power. The voltage that is present
on pin2 and pin3 of the XLR-connector could lead to severe
damage to the microphones. When in doubt, contact your dealer
before you perform any connections.
Page 10

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
19. INPUT 1-10 sensitivity switches: By moving these switches onto
the LINE position the corresponding input can be connected to
an audio source with high level signal output. By turning these
switches onto the MIC position, the corresponding input can be
connected to a dynamic microphone with low impedance. By
turning these switch onto 24V position, connects the 24V
phantom supply on XLR of pin2 and pin3 of inputs, necessary to
operate a condenser type microphone which require this type of
e ternal supply. It is recommended to operate this switch only
when the master volume set on minimum.
20. AUX1-2 input sensitivity switch: By turning switch onto the 1
position, the AUX 1 , AUX 2 input is suitable for connecting to
a CD player signal. The 2 position, is best used for an AM/FM
tuner signal output. By turning this switch onto the3" position, the
AUX1 AUX2 input is balanced for a desktop cassette player
signal output. The 4 position, provides the best match for high-
level signal outputs.
21. TEL. Paging input level control: This control let you set the
volume of the sound source that is connected to the Tel. Paging
(23) terminals. Turning the control clockwise can increase the
volume of the corresponding source. We recommend to leave
the control at its minimum setting 0 when it is not used.
22. LINE OUTPUT CONNECTOR: This XLR balanced output mi es
audio signals of all sources that can be utilized to feed an e ter-
nal tape deck or an other e ternal appliance. The volume level
can be set to a fi ed level or a variable output level controlled by
the master volume knob.
Page 11

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
23. Input TEL.Paging: It lets you connect to an au iliary signal (600
ohms). The input features the Voice Priority function, which
overrides all other input signals, once an au iliary message is
sent.
24. Priority terminal: When short-circuiting these terminals (i.e
means of using an electrical switch). The audio signals coming
from AUX1, AUX2,CASSETTE and TUNER are attenu-
ated, while the signals coming from the inputs 1-10 remain
unchanged.
25. Output terminal for au iliary loudspeaker: The terminal is meant
for the connection of a small e ternal 8 ohm loudspeaker that
gets driven by an internal au iliary power amplifier, providing a
nominal output of 1 watt. Only the mi ed audio signal coming
from AUX1 , AUX2 CASSETTE and TUNER are included
in the output signal. In addition, the output signal is controlled
only by the volume controls of the AUX1,AUX2",TUNER and
music signal level control(4).
26. DC switch: This switch lets you turn the battery supply on or off.
Page 12

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Appendix A: Limited Warranty
Electro-Voice ® amplifiers are guaranteed against malfunction due to
defects in materials or workmanship for a period of three (3) years from
the date of original purchase.
If such malfunction occurs during the specified period, the product will be
repaired or replaced (at our discretion) without charge. The product will
be returned to the customer prepaid.
Exclusions and Limitations
The Limited Warranty does not apply to: (a) e terior finish or appearance;
(b) certain specific items described in the individual product-line state-
ments below, or in the individual product sheet or owners manual; (c)
malfunction resulting from use or operation of the product other than as
specified in the product data sheet or owners manual; (d) malfunction
resulting from misuse or abuse of the product; or (e) malfunction occur-
ring at any time after repairs have been made to the product by anyone
other than Electro-Voice ® Service or any of its authorized representa-
tives.
Obtaining Warranty Service
To obtain warranty service, a customer must deliver the product, prepaid,
to Electro-Voice ® Service or to any of its authorized service representa-
tives, together with proof of purchase of the product in the form of a bill of
sale or receipted invoice. A list of authorized service representatives is
available from Electro-Voice ® Service at:
12000 Portland Avenue South
Burnsville, MN 55337
Phone: [phone]
Incidental and Consequential Damages E cluded
Product repair or replacement and return to the customer are the only
remedies provided to the customer. Electro-Voice ® shall not be liable for
any incidental or consequential damages including, without limitation,
injury to persons or property or loss of use. Some states do not allow the
e clusion or limitation of incidental or consequential damages, so the
above limitation or e clusion may not apply to you.
Other Rights
This warranty gives you specific legal rights, and you may also have other
rights which vary from state to state.
Page 13

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Appendix B: Safety uidelines
At all times, the amplifier has to be operated under appropriate condi-
tions. This includes choosing an operation location that provides sufficient
ventilation and that the device is not e posed to direct sunlight including
the direct radiation or reflection from any heat source. When installing the
loudspeaker systems choose a location that does not transmit e treme
and/or constant vibration or other mechanical oscillation.
Do not take the risk of electro-shock or shock hazard. To reduce the risk
of electro-shock, all connections have to be accomplished before it is
permissible to connect the amplifier to the main supply. Verify that all
e ternal connections are complete and that no short-circuits e ist in any
of the wiring. The overall sound reinforcement installation has to be in
accordance to the laws, regulations, standards, and guidelines that are
relevant and applicable in the country/locality where the equipment is
going to be operated.
AC Power Supply
This equipment operates from a power source that does not apply more
than 244 VAC between the supply conductors or between either supply
conductor and ground.
DC Power Supply
A 24V DC power source (i.e. a battery) has to be connected to the
terminals (13) that are covered by a protective lid. To reduce the risk of
dropping voltage to a minimum and to eliminate the danger of damaging
the battery cables by thermal overload, these cables have to be at least
2.5mm in diameter, each Switching the amplifier on or off is performed
through the power switch (6).
Safety Precautions
1. Please read the notes proceeded by the symbol with special
attention, as they provide important safety information.
2. The power supply voltage of the amplifier has a sufficiently high
value to involve the risk of electrical shock; therefore, never
install, connect, or disconnect the equipment with the power
supply switched on.
3. The metal parts of the equipment are earthed by means of the
power cable. If the power socket used to supply power does not
have an earth connection, call a qualified electrician who will
earth the equipment by means of the terminal.
Page 14

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Safety Precautions (cont )
4. Make sure that the power supply cable of the equipment cannot be
trodden on or crushed by objects.
5. There are no parts inside that can be serviced.
6. Make sure that no objects or liquids can get into the amplifier, as
this could cause a short circuit.
7. Never attempt to make any repairs that are not described in this
manual. Contact your authorized service centers or highly
qualified personnel when:
•The equipment does not function (or functions in an
abnormal way).
•The power supply cable has been seriously damaged.
•Objects or liquids have got into the equipment.
•The equipment has been subject to heavy impact.
8. If the equipment is not to be used for long periods of time, switch it
off and disconnect the power supply cable.
9. If the equipment gives off any strange odor or smoke, switch it off
immediately and disconnect the power from the supply cable.
Page 15

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Technical Specifications
2121-AM6021-AM
:)zHk1ta(tuptuOrewoPsttaW021sttaW06
:esnopseRycneuqerFBd3/+,zHk51zH05Bd3/+,zHk51zH05
ecnadepmI/ytivitisneS/tupnI
:gnitteSciM011stupnI)decnalab(mho006/Vm3.0)decnalab(mho006/Vm3.0
:gnitteSeniL011stupnI)decnalab(mhok74/Vm57)decnalab(mhok74/Vm57
:gnigaPmho006/mBd02
)detalosiremrofsnart(
mho006/mBd02
)detalosiremrofsnart(
:nIpmArewoP)decnalabnu(mhok01/V1)decnalabnu(mhok01/V1
:xuA)decnalabnu(V1otVm001)decnalabnu(V1otVm001
:)tuptuodetarta(DHTzHk1ta%1<zHk1ta%1<
oitaResioN-ot-langiS
:ciMBd25<Bd25<
:xuABd56<Bd56<
:gnigaPBd56<Bd56<
:nIpmArewoPBd09<Bd09<
ecnadepmI/leveLtuptuOeniL
:tuptuOpmaerP)decnalabnu(mhok1/V1)decnalabnu(mhok1/V1
:tuptuOeniLdecnalaB)decnalabnu(mhok74/Vm005)decnalabnu(mhok74/Vm005
:stuptuOrekaepStloV001dna,7.07,52,mho61,8,4 tloV001dna,7.07,52,mho61,8,4
slortnoenoT
:ssaBzH001taBd01/+zH001taBd01/+
:elberTzHk01taBd01/+zHk01taBd01/+
:gnituMnoitaunettaBd04noitaunettaBd04
:noitcetorPyramirp,sesufolBolStnadnepedni3
CDdnaCA
yramirp,sesufolBolStnadnepedni3
CDdnaCA
:noitapissiDrewoPsttaW093sttaW002
:ylppuSrewoPzH06/05,CAV231801zH06/05,CAV231801
:)DxWxH(miD"6.21x"9.81x"9.5
)mm023xmm084xmm051(
"6.21x"9.81x"9.5
)mm023xmm084xmm051(
:thgieWteN)gk0.21(sbl4.62)gk0.9(sbl8.91
:thgieWgnippihS)gk7.21(sbl0.82)gk7.9(sbl4.12
Page 16

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Notes

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
Notes

Electro-Voice®®
®®
®
MA-1206 and MA-1212 User Manual
U.S.A. and Canada:
For customer orders, contact the Customer Service department at:
800/392-3 97 Fax: [phone]
For warranty repair or service information, contact the Service Repair
Department at:
800/685-2606
For technical assistance, contact Technical Support at:
866/78-AUDIO
Specifications subject to change without notice.
All Other International Locations:
952-88 - 051 Fax: [phone]
www.electrovoice.com l Telex Communications, Inc. l www.telex.com
Printed in U.S.A
© Telex Comm nications, Inc. 10/2002
Part N mber 38110-190 Rev A