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Power Consumption (both channels
operating in dual mode,
1
/
8
power),
4 Ohms:
550 VA
Dimensions, (See Figure 1)
Height:
88.1 mm (3.5 in.)
Width:
483 mm (19.0 in.)
Depth:
426 mm (16.8 in.)
Color:
Gray
Net Weight:
16 kg (36 lb)
Shipping Weight:
17 kg (37.5 lb)
DESCRIPTION
The Electro-Voice P1200 Precision Series
TM
amplifier is a very-high-quality power amplifier
designed to elicit maximum performance from
any speaker system. Its ultralow distortion and
powerful amplifiers ensure that program mate-
rial will be amplified very accurately.
Each channel of the P1200 delivers more than
350 watts continuous average power into
8 ohms, 500 watts into 4 ohms and 600 watts
into 2 ohms over the full audio frequency range.
In the bridge mode, the amplifier can deliver
more than 740 watts into 8 ohms and 1,300
watts into 4 ohms at less than 1% THD. The
power supply, with its large toroidal transformer,
gives the amplifier impressive headroom and
current output.
The P1200 contains 20 high-power output de-
vices with 5,000 watts of dissipation capability.
These devices are protected from overheating
by two, three-speed, temperature-sensitive fans.
The fans are quiet enough to permit use of the
P1200 in noise-sensitive applications such as
recording studios and houses of worship.
The output devices are mounted to a massive,
extruded-aluminum heat sink that is engineered
to minimize thermal gradients and allow the
amplifier to operate safely into low-impedance
loads. The output devices have a maximum
junction temperature of 200 °C (392 °F), so high
operational temperatures present no problems.
The output devices are mounted directly to the
heat sink without mica insulators to ensure
better dissipation of heat.
Many electronic circuit innovations exist in the
P1200. Among the most novel of these circuits
is the Dual Differential Discrete Topology
TM
.
This circuit is part of the front end of the ampli-
fier and uses discrete electrical components
instead of integrated circuits and is fully sym-
metrical for both polarities.
The P1200 has sophisticated protection cir-
cuits that guard it and the load from problems.
Protection circuits guard against overload,
overtemperature, shorted outputs, radio-fre-
quency interference and dc faults. The output
devices are protected against damage from
reverse feeding of electrical energy (back EMF)
and are switched on via relays to avoid tran-
sients which could damage speakers.
The P1200 has built-in limiters to protect speak-
ers from the deleterious effects of amplifier
clipping. The limiter’s action is governed by
very sophisticated input/output comparators
which have acoustically optimized time con-
stants to preserve the integrity of the source.
The limiter’s time constants are switchable fast/
slow, so the limiter may be matched to the
application for which the amplifier is being
used.
The P1200 has built-in switchable high- and
low-cut filters. These filters attenuate infrasonic
and ultrahigh-frequency signals, preventing
them from being amplified; this allows more
effective use of the amplifier’s power and adds
a measure of load protection. These filters are
switchable on/off for use in applications utiliz-
ing frontend units (like crossovers or equaliz-
ers) which have these filters built-in.
A multifunction display keeps the user informed
of the operating status of the amplifier. Sepa-
rate LED displays for each channel show power
on, input signal, output signal, limiter on and
protection active.
The P1200 has electronically balanced XLR-
type input and output connectors that allow
easy, problem-free connections and signal rout-
ing. The P1200 has an input routing switch that
allows selection of either normal dual-channel
operation, or parallel mono operation, which
routes an input to both channels but still allows
for independent level control. The P1200 also
has a constant-gain option which allows the
voltage gain to be fixed. This permits different
amplifiers to be used in fixed installations with-
out rebalancing, and ensures headroom is not
wasted.
The P1200’s output connectors are profes-
sional Neutrik Speakon
®
connectors which pro-
vide a sturdy, reliable connection and allow use
of heavy wire for loss-free signal transmission.
There are separate output connectors for chan-
nels A and B, and for the bridge mode. The
bridge-mode connector is sealed with a plastic
cover to prevent connection errors.
To prevent ground loops from occurring, the
P1200 is equipped with a ground-lift switch.
When the amplifier is operated in a rack with
units of different ground potential, the switch
may be adjusted to eliminate hum.
Calibrated, detented potentiometers on the front
panel regulate the gain of the P1200. The panel
nomenclature shows the amount of attenuation
accurately.
The P1200 also has a constant-gain option
which, with input level controls full clockwise,
provides a 26-dB voltage gain that is identical to
that of all Electro-Voice Precision Series
TM
am-
plifiers in the constant-gain option, regardless
of power rating. This makes it possible to ex-
change amplifiers of different power ratings
without upsetting delivered sound pressure lev-
els or spectral balances.
The Electro-Voice P1200 is the choice for seri-
ous, professional amplification applications
which require optimum sound quality, speaker
protection, and the highest level of construction
quality and long-term reliability.
Figure 3 shows P1200 front and rear panels.
The block diagram is shown in Figure 4.
ARCHITECTS’ AND ENGINEERS’
SPECIFICATIONS
The power amplifier shall be a dual-channel
model of solid-state design employing high-
power output devices in a true-complementary-
symmetry output circuit . It shall be capable of
operating from a 120/200/220/240-V, 50/60-Hz
ac line. The power amplifier shall contain a
modern limiter circuit with switchable time con-
stants to protect the load from damage by
amplifier clipping.
The amplifier shall contain sensing circuitry to
provide protection for the output transistors
against overtemperature, excessive output
voltage, radio-frequency interference, shorted
loads and excessive phase shift. The load shall
be similarly protected against infrasonic sig-
nals, startup/shutdown transients, low ac line
voltage and dc.
Rear-mounted panel controls shall include an
input routing switch for selecting dual/stereo or
parallel mono operation, a switch for turning the
infrasonic and ultrasonic filters on or off, a
switch for selecting dual/stereo or bridged op-
eration and a switch for selecting fast or slow
speed for the built-in limiters. Input connections
for each channel shall include a 3-pin female
XLR-type connector wired in parallel with a
male 3-pin XLR output connector for signal
routing. Output connectors shall be Neutrik
Speakon
®
NL4MP’s for channels A and B, and
for bridged operation.
Front-panel indicators shall include power on,
input present, output, limit and protect LEDs for
each channel. Front-panel controls shall in-
clude a power switch and level controls that
shall be calibrated, detented potentiometers
and have accurate markings. The amplifier
shall have a constant-gain option that, with
input level controls full clockwise, provides a
26-dB voltage gain that is identical to that of all
Electro-Voice Precision Series
TM
power ampli-
fiers.
The power amplifier shall meet the following
performance specifications: maximum input
voltage, 7.75 V rms; rated output power from
20-20,000 Hz at less than 0.1% THD, each
channel, >350 watts into 8 ohms, 500 watts into
4 ohms, 600 watts into 2 ohms, 1,000 watts
bridged into 8 ohms and 1,300 watts bridged
into 4 ohms; hum and noise, at least 100 dB (A-
weighted) below rated output power; frequency
response, 10-30,000 Hz(+0/–1 dB) at any out-
put power up to rated output power; damping
factor, >300 at any frequency up to 1 kHz in any
mode with an 8-ohm load; THD (total harmonic
distortion), <0.05% at 1 kHz at rated power;
transient intermodulation distortion (DIN 30 or
DIN 100), <0.01%; crosstalk, <70 dB below
rated output power. Dimensions shall be 88.1
mm (3.5 in.) x 483 mm (19.0 in.) x 426 mm 16.8
in.) hwd. Net weight shall be 17 kg (37.5 lb).
Color: gray.
The power amplifier shall be the Electro-Voice
P1200.