P1200 Precision SeriesTM Power Amplifier - Electro

Precision SeriesTM
Power Amplifier
1. 0 dBu = 0.775 V rms.
2. Dual-mode ratings are for each channel,
both operating, unless noted.
3. 120-volt ac line voltage maintained
throughout testing.
Continuous Rated Output Power (2020,000 Hz at less than 0.1% THD, both
channels driven per EIA RS-490),
Dual Mode, 2 Ohms:
600 watts
Bridged Mode, 4 Ohms:
1,200 watts
Dual Mode, 4 Ohms:
500 watts
Bridged Mode, 8 Ohms:
1,000 watts
Dual Mode, 8 Ohms:
350 watts
Continuous Rated Output Power (1 kHz,
1% THD, both channels driven per EIA
Dual Mode, 2 Ohms:
650 watts
Bridged Mode, 4 Ohms:
1,300 watts
Dual Mode, 4 Ohms:
550 watts
Bridged Mode, 8 Ohms:
1,100 watts
Dual Mode, 8 Ohms:
370 watts
Power Bandwidth
(+0/–1 dB, reference 1 kHz),
Dual Mode, 4 Ohms:
20-20,000 Hz
Bridged Mode, 8 Ohms:
20-20,000 Hz
Dual Mode, 8 Ohms:
20-20,000 Hz
Frequency Response
(–1 dB, reference 1 kHz/1 watt):
10-30,000 Hz
Voltage Gain, 1 kHz, Input Level Controls
Full Clockwise, Constant-Gain Option:1
26 dB
Input Sensitivity, 1 kHz, Dual Mode for 550
Watts into 4 Ohms:
0 dBu (775 mV)
Maximum Input Level (reference 1 kHz):
+20 dBu (7.75 V)
Input Impedance (per channel,
20-20,000 Hz), Balanced:
20 kilohms
Phase Response (at rated power, any
mode, 10-30,000 Hz):
±22.5 degrees
THD Plus Noise at 1 kHz (at rated power,
measurement bandwidth 80 kHz):
IMD (SMPTE) (60 Hz/7 kHz, typical, at
rated power; see Figure 2):
Rise Time (10% to 90% at rated power,
any mode):
<2.5 microseconds
Slew Rate, Any Mode:
>30 V/microsecond
Damping Factor, Any Mode:
Amplifier Protection:
Excessive output voltage; shorted loads;
excessive phase shift; rf interference;
overtemperature; excessive back EMF;
In-rush current limiter
Load Protection:
Start-up/shutdown transients; dc fault;
infrasonic signals; low ac line voltage;
nonlinear signal limiter
1. Configured for constant-gain option, all Precision SeriesTM
amplifiers, regardless of power rating, have a maximum
voltage gain of 26 dB.
370 watts per channel
at 8 ohms, 550 watts per
channel at 4 ohms, 650
watts per channel at 2 ohms
Compact, two-rack-space
Neutrik Speakon® output
connectors allow use of
heavy-gauge speaker wire
for low-loss connections
Three-year parts-and-labor
Output Topology:
True complementary symmetry with
ungrounded collectors (no mica insulators
means better heat transfer)
Output Devices,
Total Number: 20 devices
Pd(max) Rating: 250 watts
Ic (collector current): 16 amps dc
Tj(max): 200 °C (392 °F)
Controls and Switches,
Hi-Lo-Cut Filter(On/Off); Bridged Mode
switch (Bridged/Normal); Limiter mode
(Fast/Slow); Circuit ⊥ To Chassis
Switch (Grounded/Ungrounded); Input
Routing (Parallel Mono or Dual Stereo)
Two calibrated input level controls;
power switch
Front-Panel Indicators:
Five LED’s per channel (10 total) for power
on, input signal; output signal; limiter
on and protect on
3-pin female XLR-type connectors for
each channel in parallel with a 3-pin
male XLR-type output connector for
easy signal routing; the XLR connectors are wired according to the IEC 268
standard: pin 1 shield, pin 2 positive,
pin 3 negative
Neutrik Speakon® NL4MP for channels
A, B and for bridged mode
14-gauge, 3-wire, permanently attached
power cable;
Operating Voltage:
120 V, 60 Hz ac
FIGURE 1 — P1200 Dimensions
FIGURE 3 — P1200 Front and Rear Panel
FIGURE 2 — P1200 Intermodulation Distortion
(SMPTE 60 Hz/7,000 Hz) vs. Power
Power Consumption (both channels
operating in dual mode, 1/8 power),
4 Ohms:
550 VA
Dimensions, (See Figure 1)
88.1 mm (3.5 in.)
483 mm (19.0 in.)
426 mm (16.8 in.)
Net Weight:
16 kg (36 lb)
Shipping Weight:
17 kg (37.5 lb)
The Electro-Voice P1200 Precision SeriesTM
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 material 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 devices 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 TopologyTM.
This circuit is part of the front end of the amplifier and uses discrete electrical components
instead of integrated circuits and is fully symmetrical for both polarities.
The P1200 has sophisticated protection circuits that guard it and the load from problems.
Protection circuits guard against overload,
overtemperature, shorted outputs, radio-frequency 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 transients which could damage speakers.
The P1200 has built-in limiters to protect speakers from the deleterious effects of amplifier
clipping. The limiter’s action is governed by
very sophisticated input/output comparators
which have acoustically optimized time constants 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
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 utilizing frontend units (like crossovers or equalizers) which have these filters built-in.
A multifunction display keeps the user informed
of the operating status of the amplifier. Separate LED displays for each channel show power
on, input signal, output signal, limiter on and
protection active.
The P1200 has electronically balanced XLRtype input and output connectors that allow
easy, problem-free connections and signal routing. 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 without rebalancing, and ensures headroom is not
The P1200’s output connectors are professional Neutrik Speakon® connectors which provide a sturdy, reliable connection and allow use
of heavy wire for loss-free signal transmission.
There are separate output connectors for channels 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
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 SeriesTM amplifiers in the constant-gain option, regardless
of power rating. This makes it possible to exchange amplifiers of different power ratings
without upsetting delivered sound pressure levels or spectral balances.
The Electro-Voice P1200 is the choice for serious, 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.
The power amplifier shall be a dual-channel
model of solid-state design employing highpower output devices in a true-complementarysymmetry 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 constants 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 signals, 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 operation 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 include 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 SeriesTM power amplifiers.
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 (Aweighted) below rated output power; frequency
response, 10-30,000 Hz(+0/–1 dB) at any output 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
Electro-Voice products are guaranteed against
malfunction due to defects in materials or workmanship for a specified period, as noted in the
individual product-line statement(s) below, or in
the individual product data sheet or owner’s
manual, beginning with the date of original
purchase. If such malfunction occurs during the
specified period, the product will be repaired or
replaced (at our option) without charge. The
product will be returned to the customer prepaid. Exclusions and Limitations: The Limited Warranty does not apply to: (a) exterior
finish or appearance; (b) certain specific items
described in the individual product-line
statement(s) below, or in the individual product
data 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 re-
sulting from misuse or abuse of the product; or
(e) malfunction occurring at any time after repairs have been made to the product by anyone
other than Electro-Voice or any of its authorized
service representatives. Obtaining Warranty
Service: To obtain warranty service, a customer must deliver the product, prepaid, to
Electro-Voice or any of its authorized service
representatives 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
at 600 Cecil Street, Buchanan, MI 49107 (616/
695-6831 or 800/234-6831). Incidental and
Consequential Damages Excluded: 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 exclusion or limitation of incidental or
consequential damages so the above limitation
or exclusion 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.
Electro-Voice Electronics are guaranteed
against malfunction due to defects in materials
or workmanship for a period of three (3) years
from the date of original purchase. Additional
details are included in the Uniform Limited
Warranty statement.
Service and repair address for this product:
Electro-Voice, Inc., 600 Cecil Street, Buchanan,
Michigan 49107 (616/695-6831 or 800/2346831).
Specifications subject to change without notice.
FIGURE 4 — P1200 Block Diagram
a MARK IV company 600 Cecil Street, Buchanan, Michigan 49107
© Electro-Voice, Inc. 1995
Litho in U.S.A.
Part Number 532406 — 9530