Electro-Voice Precision P 1200 User manual

P1200
Precision SeriesTM
Power Amplifier
• 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
chassis
• Neutrik Speakon®output
connectors allow use of
heavy-gauge speaker wire
for low-loss connections
• Three-year parts-and-labor
warranty
SPECIFICATIONS
Conditions:
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 (20-
20,000 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
RS-490),
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):
<0.01%
IMD (SMPTE) (60 Hz/7 kHz, typical, at
rated power; see Figure 2):
<0.01%
Rise Time (10% to 90% at rated power,
any mode):
<2.5 microseconds
Slew Rate, Any Mode:
>30 V/microsecond
Damping Factor, Any Mode:
>300
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
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,
Rear:
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)
Front:
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
Connections,
Input:
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 connec-
tors are wired according to the IEC 268
standard: pin 1 shield, pin 2 positive,
pin 3 negative
Output:
Neutrik Speakon®NL4MP for channels
A, B and for bridged mode
Power:
14-gauge, 3-wire, permanently attached
power cable;
Operating Voltage:
120 V, 60 Hz ac
__________________
1. Configured for constant-gain option, all Precision SeriesTM
amplifiers, regardless of power rating, have a maximum
voltage gain of 26 dB.

P1200 SPECIFICATION GRAPHICS
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, 1/8power),
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 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 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
into2ohmsoverthefullaudiofrequencyrange.
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
powersupply,withitslargetoroidaltransformer,
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
bytwo,three-speed,temperature-sensitivefans.
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-aluminumheatsinkthatisengineered
to minimize thermal gradients and allow the
amplifier to operate safely into low-impedance
loads. The output devices have a maximum
junctiontemperatureof200°C(392°F),sohigh
operationaltemperaturespresentnoproblems.
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 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
reversefeedingofelectricalenergy(backEMF)
and are switched on via relays to avoid tran-
sients which could damage speakers.
TheP1200hasbuilt-inlimiterstoprotectspeak-
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.
Thelimiter’stimeconstantsareswitchablefast/
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-cutfilters.Thesefiltersattenuateinfrasonic
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.
Amultifunctiondisplaykeepstheuserinformed
of the operating status of the amplifier. Sepa-
rateLEDdisplaysforeachchannelshowpower
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-freeconnectionsandsignalrout-
ing.TheP1200hasaninputroutingswitchthat
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-
sionalNeutrikSpeakon®connectorswhichpro-
videasturdy,reliableconnectionandallowuse
of heavy wire for loss-free signal transmission.
Thereareseparateoutputconnectorsforchan-
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,detentedpotentiometersonthefront
panelregulatethegainofthe P1200.Thepanel
nomenclatureshowstheamountofattenuation
accurately.
The P1200 also has a constant-gain option
which, with input level controls full clockwise,
providesa26-dBvoltagegainthatisidenticalto
that of all Electro-Voice Precision SeriesTM am-
plifiers in the constant-gain option, regardless
of power rating. This makes it possible to ex-
change amplifiers of different power ratings
withoutupsettingdeliveredsoundpressurelev-
els or spectral balances.
The Electro-Voice P1200 is the choice for seri-
ous, professional amplification applications
which require optimum sound quality, speaker
protection,andthehighestlevelofconstruction
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-
poweroutputdevicesinatrue-complementary-
symmetry output circuit . It shall be capable of
operatingfroma120/200/220/240-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
loadsandexcessive phaseshift.Theloadshall
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
parallelmonooperation,aswitchforturningthe
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
speedforthebuilt-inlimiters.Inputconnections
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,
inputpresent,output,limitandprotect LEDsfor
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 SeriesTM 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,>350wattsinto8ohms,500wattsinto
4 ohms, 600 watts into 2 ohms, 1,000 watts
bridged into 8 ohms and 1,300 watts bridged
into4 ohms;humand noise,at least 100dB (A-
weighted)belowratedoutputpower;frequency
response, 10-30,000 Hz(+0/–1 dB) at any out-
put power up to rated output power; damping
factor,>300atanyfrequencyupto1kHzinany
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 426mm16.8
in.) hwd. Net weight shall be 17 kg (37.5 lb).
Color: gray.
The power amplifier shall be the Electro-Voice
P1200.

ELECTRO-VOICE a MARK IV company 600 Cecil Street, Buchanan, Michigan 49107
MANUFACTURING PLANTS AT BUCHANAN, MI NEWPORT, TN SEVIERVILLE, TN OKLAHOMA CITY, OK GANANOQUE, ONT.
© Electro-Voice, Inc. 1995 Litho in U.S.A. Part Number 532406 — 9530
UNIFORM LIMITED WARRANTY
Electro-Voiceproductsareguaranteedagainst
malfunctionduetodefectsinmaterialsorwork-
manship for a specified period, as noted in the
individualproduct-linestatement(s)below,orin
the individual product data sheet or owner’s
manual, beginning with the date of original
purchase.Ifsuchmalfunctionoccursduringthe
specifiedperiod, the product will be repaired or
replaced (at our option) without charge. The
product will be returned to the customer pre-
paid. Exclusions and Limitations: The Lim-
ited 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 re-
pairshavebeenmadetotheproductbyanyone
otherthanElectro-Voiceoranyofitsauthorized
service representatives. Obtaining Warranty
Service: To obtain warranty service, a cus-
tomer must deliver the product, prepaid, to
Electro-Voice or any of its authorized service
representativestogetherwithproofofpurchase
of the product in the form of a bill of sale or
receipted invoice. A list of authorized service
representativesis 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 cus-
tomer are the only remedies provided to the
customer. Electro-Voice shall not be liable for
any incidental or consequential damages in-
cluding, without limitation, injury to persons or
property or loss of use. Some states do not
allow the exclusion or limitation of incidental or
consequentialdamagessotheabovelimitation
orexclusionmaynotapplytoyou.OtherRights:
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.,600Cecil Street,Buchanan,
Michigan 49107 (616/695-6831 or 800/234-
6831).
Specifications subject to change without notice.
FIGURE 4 — P1200 Block Diagram