Power Consumption (both channels operating in dual mode, 1/8 power),
4Ohms: 550 VA
Dimensions, (See Figure 1)
Height:
88.1mm (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 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 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 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 SeriesTM 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 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, >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.
