AT4003 (PZA)
3 channels - 200 watts/channel
Amplifier Technologies, Inc., the prolific manufacturer of many of the finest high-end amplifiers, has introduced a new series of amplifiers designed by its president and chief engineer, Morris Kessler. The ATI AT4003 amplifier and all AT4000 Signature Series amplifiers, available with 2 to 7 channels, share the design philosophy and circuit sophistication of ATI's award-winning 6000 Series amplifiers with power output reduced to 200W RMS per channel at 8 ohms and 300W RMS at 4 ohms. Furthermore, their "Signature Series" designation with a facsimile of Kessler's signature on the main panel attests to the special nature of these amplifiers.
The ATI AT 4003 amplifier and all AT4000 series amplifiers are rated at 200 watts RMS/channel into 8 ohms from 20 Hz to 20 kHz with no more than 0.03% THD with all channels driven and 300 watts RMS into 4 ohms under the same conditions. The ATI AT 4003 amplifier has a signal-to-noise ratio that is typically 126 dB referenced to full output, so each amplifier in the series is capable of reproducing the full dynamic range available in today's lossless recordings. The AT4000 is available in 2- to 7-channel configurations and can be upgraded by adding 200-watt power modules.
Beyond Kessler's personal identification, these amplifiers are new in more significant ways:
- As with Kessler's previous top-of-the-line designs, these amplifiers are fully balanced differential amplifiers, but unlike their previous balanced designs which were essentially balanced bridged amplifiers, the 4000 Series uses only one input stage with dual differential output stages. The reason: the advantages of balanced designs are maintained and noise is reduced by 50%.
- The design uses current feedback instead of the more common voltage feedback. The reason: Today's feedback amplifiers are faster, with virtually unlimited slew rate, and can better reproduce today's best music and movies.
- Kessler used Thermaltrak output devices for the 4000 series. Unlike traditional designs where external diodes connected to heat sinks track the operating conditions of the amplifiers and use the details to adjust biasing, Thermaltrak devices have the diodes in the same package as the transistors. The results: bias is optimized in real time.
- The 4000 series uses dual DC servos to track and maintain DC offset. The result: the DC at the amplifier output is reduced to negligible levels.
- All amplifiers in the series use dual toroidal transformers with independent secondary windings. Electrically, each channel of the amplifier has its own transformer.
Remote Trigger:Triggered from 3.3 VDC to 24 VDC by a heavy duty relay.Protection Circuitry:Optically coupled with full auto reset.Toroidal Transformers:40% more efficient than EI type. Separate bifilar windings for each channel ensure lower noise and crosstalk.Circuit Boards:Double-sided, computer-grade FR-4 glass and epoxy boards are assembled in-house.Soft Start Circuitry:Ultra-soft turn-on reduces in-rush current to a minimum. Multiple units can be powered up without tripping circuit breakers, eliminating the need for sequencing. Power Transistors: High-current bipolar output transistors with active bias circuitry result in effortless operation. Thermaltrak Output Devices: Thermaltrak devices have tracking diodes in the same package as the transistors, so bias is optimized in real time. Power Cord: Detachable 3-wire cord. 7-Year Warranty: Parts and labor against defects in parts or workmanship. Dimensions: 17.25" W x 7.875" H x 17" D (chassis). Handles protrude 1 3/4" (44.5 mm); add 1 1/4" (32 mm) for input/output jacks. Weight: 86 to 136 lbs (depending on model). More Features