Electro voice ev 1244 x brochure

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Edema/:12: ENGINEERING DATA

DESCRIPTION

The EV 1244X amplifier provides easy expansion of an
existing stereo system into 4-channel operation. In ad-
dition to two complete amplifier channels with full
controls, the EV 1244X includes the Electro-Voice
STEREO-4 integrated circuit decoder. By decoding
records and FM stereo broadcasts which have been pre-
viously encoded with 4-channel material, four distinct
sources of sound can be recreated in the home using
conventional stereo phono cartridges and standard FM
stereo tuners. No portion of an existing stereo system
becomes obsolete.

In addition to the recovering of four channels from a
STEREO-4 encoded program, the E-V 1244X decoder
creates a remarkable enhancement of conventional two.
channel program material. While this enhancement is not
real" four-channel, the effect ranges from pleasing to
astounding, depending upon the information contained in
the stereo signal. If four-channel playback or enhance:
ment is not desired, the decoder is easily bypassed for
conventional system operation.

Because the EV 1244X has full switching and control
facilities, it may be used with an existing stereo system for
4-channel tape playback. Either open reel or cartridge
machines may be used: The E-V 1244X may also be used
independently as the heart of a fine 2-channel stereo
system.

SPECIFICATIONS
Power Output,

[HF Music Power: 65 watts into 4 ohms,
50 watts into 8 ohms
Continuous Sine Wave: 18 watts per channel
Frequency Response: 1 1.5 dB,
20-20,000 Hz at rated output
: 1.5 dB,
20-30,000 Hz at 1 watt

E-V STEREO-4 TM SYSTEM PERMITS:

O Playback of 4channel phonograph records

0 Reception of 4-channel FM Broadcasts

0 Dramatic enhancement of ordinary 2-channel
stereo records, tapes and broadcasts

Less than 1.0%
at rated output

Harmonic Distortion:

Hum and Noise,

High Level Inputs: Better than 70 dB
below rated output
Magnetic Phono Input: Better than 60 dB
below rated output

Channel Separation: 40 dB minimum at 1,000 H2
Inputs: Mag. Phono, Tuner, Aux, Tape (high level)
Input Sensitivity,

Phono: 3 mv

Tuner, Aux, Tape: 150 mv
Controls (Rotary),

Volume: with on/off switch

Balance: with Pull/Mono switch

Selector: Phono-Tuner-Aux

Bass: +10 dB, -12 dB at 50 Hz

Treble: + to dB,-lZ dB at lOkHz
Controls (Switches),

Decode On/Off

Source/T ape

Speaker Orr/Mute

Loudness On/Off

Amp. Selector Front/Back

Tape Monitor Tape Mon 2/Nomtal
Outputs,

Speakers: 4-16 ohms per channel

Line Outputs: to other amplifiers

Stereo Tape Recorder

Stereo Headphones: on front panel

Output Damping Factor: 35 at 8 ohms
Auxiliary AC Outlet: one switched
Power Requirements: 1 10-120 volts,

50-60 Hz AC

Dimensions: 33/8" h., 8-3/8 w., 10%" d.

SYSTEM REQUIREMENTS
For four independent sound channels to exist, there must

E-V1244X WED-4 AMPLIFIER

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be four separate power amplifiers (two stereo amplifiers)
and four speakers. The E-V 1244x is designed primarily
to add two Back channels to'an existing stereo system.
Connection to the existing stereo electronics are easily
made if your present unit includes a tape monitor (also
called tape-source) switch. Through the use of the tape
monitor connection, and with the flexibility provided on
the E-V 1244X, a wide range of 4-channel operation is
available, and yet your system can be returned to its
original stereo form in just a second.

The E-V 1244X has a switch on the chassis which permits
selection of either Front or Back amplifier operation. For
the purposes of the connection and operating instructions,
it is assumed that the E-V 1244X will be used to power
the Back speakers and that your present stereo system will
become the Front channels.

While the selection of equipment for a 4-channel system is
a concern to many, the criteria for good performance are
less severe than for 2-channel stereo. As is the case with
2-channel stereo, acoustical performance is best balanced
if all four speakers are the same. However, the results are
still excellent if the Back channels have more modest
speakers. For best results, however, the two Front
speakers should be closely matched. as should the Back
pair.

SYSTEM WIRING

Your present system may include an amplifier or receiver,
and you may have a variety of program sources (phono,
tuner, tape, etc.). To keep these instructions as simple as
possible, your present electronic unit is considered to
drive the Front pair of speakers and will be called the
Front amplifier; the E-V 1244X will be connected to drive
the Back speakers.

First, a few hints for a successful hookup.

I. Program sources (phono, tuner, etc.) should be
connected to the Front amplifier.
2. If the two pairs of speakers are not identical, the
better pair should be considered the Front speakers.
3. Follow the hookup directions slowly and carefully.
With so many cables to connect, it is easy to become
_ confused Observe the Left and Right channel con-
nections scrupulously. In fact, it may be less
confusing to go through the hookup steps for the
Left channel only, and then repeat the operation for
the Right channel. This way there is less chance of
interchanging channels.

CONNECTIONS

1. Using convenient length shielded audio cables, con-
nect the Front amplifiers Tape Out jacks to the EV
1244K AUX inputs.

2. Connect the EV 1244X Out To Other Amp jacks to
the Tape In jacks on the Front amplifier. At this
point you should have cables going to and from the
Front amplifier's Tape Out and Tape In jacks.

3. Connect the four speakers to the appropriate ampli-
fier output terminals. Just as the fenders of a car are
identified from the drivers seat, the speaker locations
are named while facing the front" of the 4-channel
system. Thus, the Left Back speaker is connected to
the Left speaker terminals of the Back amplifier (E-V
1244X). The positive (+, T1, red) terminal of the
Back speakers should be connected to the L or R
speaker output terminals on the EV 1244X. The
speaker common temiinals should be connected to
the terminals marked "C" on the amplifier output
strip. Be sure that the Front speakers are connected
in phase to the Front amplifier, as outlined in your
electronics and speaker instructions.

4. Connect the AC line cords to a convenient outlet.
The Front amplifier line cord may be plugged into
the switched outlet on the EV 1244X, thus turning
on both amplifiers with the EV l244X power switch.

TAPE CONNECTIONS

Twa~Channel Tape. Connect a 2-channe] tape recorder or
player to the Tape In and Tape Out jacks on the E-V
1244X. These jacks duplicate the jacks previously used on
the Front amplifier, and additionally, allow you to decode
the output of your tape recorder into four channels.

Four-Channel Tape. A 4-channel discrete open reel or
cartridge machine may be connected to play through all
four amplifier channels without decoding. Connect the
front channels (1 and 3) to the Front amplifiers AUX
inputs, and connect the back channels (2 and 4) to the
B-V 1244X Tape Inputs.

E-V 1244K CONTROL FUNCTIONS

VOLUME/POWER OFF

Adjusts listening level and controls the main AC power to
the amplifier in addition to any equipment connected to
the switched AC outlet on the rear panel. This control
should be in the Off position whenever any connection
change to the amplfier or associated equipment is made.

When the Decode switch is On, this Volume control acts
as Master Gain Control for the complete 4-channe1 sys-
tem Front-to-back balance is adjusted with the Volume
control on the Front amplifier. Once the proper front-to-
back balance is established, the volume of all four

. speakers will be controlled simultaneously with the EV

1244X Volume control.

When the Decode switch is Off. this control adjusts the
volume of the two Back speakers, while the Volume
control on the Front amplifier adjusts the volume of the
two Front speakers. There is no Master Gain Control
during discrete 4channel operation, unless it is provided
on the associated tape machine.

BALANCE
Adjusts the relative volume of the Left and Right speakers
connected to the EV 1244X. The center, or 12 o'clock

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