Phase Linear Model 400

Solid State Stereo Amplifier Model 400 has gained an international reputation as the world's mos reliable and most accurate high powered amplifier. It puts out 201 watts per channel which enables it to drive all the better bookshelf speakers as well as the most exotic loudspeakers available. It also rates better than any amplifier in its power range on a dollar per watt basis.

If you contemplating the purchase of high powered amplifier, you should audition the Phase Linear 400.

Circuit description

The Phase Linear amplifier consists of two direct coupled designed linear power amplifiers combined to form a single, dual channel unit capable of extremely high power output. The output stages employ twelve high current, high voltage, triple-diffused silicon output transistors arranged in a quasi-complimentary format and biased for class AB operation. The output stages are driven by two stages of Darlington connected current amplifiers, which in turn are driven by a predriver voltage amplifying stage swinging the full supply voltage.

The upper output transistors are driven into saturation by a constant current source and the lower transistors are driven by the predriver. Bias control is accomplished by a bias regulator consisting of two voltage reference diodes, a regulator transistor, and temperature compensating circuitry. The low level stage consists of a differential pair which provides voltage gain and level shifting to accommodate the predriver requirements.

 The patanted protective circuits consist of four small analog to digital computers,each computer monitoring the operating conditions of four output transistors. Output current,voltage, energy, time raate of current and voltage change, and common mode conduction are monitored continuously during amplifier operation. If the value any one, or the sum value of more than one or all of these quantities exceeds a safe stress level for the transistors, the computer instructs a "disconed circuit" to instantly shut down the amplifier.

Specifications:

Power:  201 watts per channel (min. RMS at 8 Ω, 20-20,000 Hz, with no more than ,25%T.H.D.)

Hum and Noise:  at least 100 dB below rated output

Damping Factor:  1000 : 1 at 20 Hz

Rise Time:  less than 1,7 microseconds

Phase Shift:  lagging 12 degrees at 20 kHz

Sensitivity:  1,75 volts for rated power output

Slew Rate:  11 volts/microsecond.

Meter ballistics:  V.U. calibration is such that impulsive waveforms result in 0 V.U. at clipping

Stability:  absolutely stable with all loudspeakers including electrostatic units.

Protection:  electronic energy limiters together with supply fuses prevent excursions into unsafe operating regions

Dimensions (W x H x D):  19" x 7" x 10"

Weight:  35 lbs

Finish:  light brushed gold, baked enamel and black anodize.