ATI AT4000 Signature Series

Description Why It Matters A great power amplifier should not call attention to itself. It should be quiet.It should be powerful.It should control the loudspeaker.It should preserve the signal.It should have enough reserve power to handle real music and movie dynamics without strain. That’s the AT4000 Series. The fully balanced differential design reduces noise, increases signal purity, and gives the amplifier the stability needed to drive demanding loudspeakers with confidence. ATI rates the AT4000 Series at greater than 125 dB signal-to-noise ratio, less than 0.03% THD N, and a damping factor of greater than 400. The SAE Pedigree Morris Kessler is one of the great amplifier designers in American high fidelity history. Before ATI, Morris co-founded SAE — Scientific Audio Electronics — one of the respected American amplifier brands of the classic hi-fi era. That same engineering DNA continues today in ATI. The Signature Series is personal. Morris’s signature appears on the front panel because these amplifiers represent his statement of what a serious modern power amplifier should be: clean, powerful, stable, durable, and built in America. Sound & Vision noted Kessler’s SAE background and ATI’s long history of building amplifiers in the USA, including work for brands such as Crestron, Theta Digital, and Outlaw Audio. What They’re Saying “This amp never broke a sweat driving my 4-ohm speakers at insanely loud levels.”— Sound & Vision, reviewing the ATI AT6005 Signature Series amplifier “The ATI would be at the top of my list, due to its low noise and seemingly endless power output.”— Sound & Vision “Incredible power reserves with dead silent backgrounds.”— Secrets of Home Theater and High Fidelity, reviewing the ATI AT6002 Signature Series amplifier “No amplifier has ever been this quiet in my system.”— Secrets of Home Theater and High Fidelity “A fully balanced, dual mono amplifier with high-end build quality… it sounds like a statement product.”— Secrets of Home Theater and High Fidelity Built for Real Loudspeakers The AT4000 Series is rated for 4-ohm to 16-ohm loudspeakers and is safe for all types of loads. That matters. Many high-performance loudspeakers present difficult impedance curves. Lesser amplifiers can sound compressed, strained, or edgy when pushed. The AT4000 Series is built for control, headroom, and composure. Whether used in a high-end stereo system, a serious 5.1 home theater, or a full 7-channel surround system, the AT4000 Series gives each channel its own clean, authoritative power. Balanced or Unbalanced Inputs Each channel includes both: Balanced XLR inputUnbalanced RCA input A rear-panel selector lets you choose the input type for each channel. This makes the AT4000 Series compatible with a wide range of stereo preamps, AV processors, legacy systems, and modern balanced-output components. AT4005: The Sweet Spot for Serious 5-Channel Systems The ATI AT4005 is the natural choice for a serious 5-channel home theater or music-surround system. It delivers: 5 channels of equal power200 watts per channel into 8 ohms300 watts per channel into 4 ohmsBalanced and unbalanced inputs on every channelMade in the USA construction7-Year Warranty For customers who already own a great surround processor or AVR with preamp outputs, the AT4005 is a major performance upgrade. It removes the heavy lifting from the receiver or processor and gives the loudspeakers the clean current they need. ATI AT4000 Signature Series — Features & Specifications Feature / Specification ATI AT4000 Series Number of Channels 2 to 7 FTC Full Bandwidth Power Output @ 8Ω 200 watts RMS per channel FTC Full Bandwidth Power Output @ 4Ω 300 watts RMS per channel Input Sensitivity for Full Rated FTC Output @ 8Ω 1.6 volts Frequency Response ±0.1 dB, 20Hz–20kHz Phase Response 5 to -15°, 20Hz–20kHz @ 1W Signal-to-Noise Ratio >125 dB, referenced to FTC rated power, A-weighted THD N, 20Hz–20kHz <0.03% Intermodulation Distortion <0.03% Recommended Load Impedance Safe for all types of loads; rated for 4Ω to 16Ω FTC Power Bandwidth 0, -3 dB, 5Hz–100kHz Damping Factor >400 Crosstalk Greater than -80 dB, 20Hz–20kHz Voltage Gain — RCA Inputs 28 dB ±0.2 dB Voltage Gain — XLR Inputs 28 dB ±0.2 dB Slew Rate >60 V/µS Input Impedance 28kΩ Output DC Offset Less than ±1mV Remote Trigger Activated from 3.3VDC to 24VDC via heavy-duty relay Protection Circuits Optically coupled with full automatic reset Toroid Transformers 40% more efficient than EI type; separate bi-filar windings for each channel ensure lower noise and crosstalk Circuit Boards Double-sided FR-4 glass-epoxy computer-grade boards, assembled in-house Soft Start Circuitry Ultra-soft turn-on reduces in-rush current to a minimum; multiple units can be turned on without tripping circuit breakers, eliminating the need for sequencing Power Transistors High-current bipolar and ThermalTrak™ output transistors optimize performance in real time Power Supply Capacitance 46,200 µF per channel Power Cord Dual detachable 3-wire cord Power Requirements Factory built for single voltage: 120VAC or 240VAC AC Circuit Requirement 1 × 20 Amp circuit Power Consumption — Standby ≤1W at 120VAC; ≤0.5W at 240VAC Power Consumption — Idle TBD Chassis Dimensions — Inches 17.0″ W × 7.75″ H × 18.0″ D Chassis Dimensions — Millimeters 440 W × 197 H × 457 D Warranty 7 years parts and labor against defects in parts or workmanship Model Weights Model Net Weight Shipping Weight AT4002 51 lbs / 23.1 kg 77 lbs / 35 kg AT4003 71 lbs / 32.2 kg 86 lbs / 39 kg AT4004 TBD 90 lbs / 41 kg AT4005 TBD 99 lbs / 45 kg AT4006 TBD 109 lbs / 50 kg AT4007 93 lbs / 42.2 kg 119 lbs / 54 kg The AT4000 Series is not lightweight equipment. It is built the old-fashioned way: heavy chassis, serious power supply, substantial output stage, and real heat-sinked amplifier hardware. The Essence Take The ATI AT4000 Signature Series is for listeners who want real amplifier authority without moving into unnecessary excess. It has the pedigree.It has the build quality.It has the power.It has the warranty.And it is made in the USA by one of America’s most respected amplifier companies. For a serious home theater, a demanding music-surround system, or a high-performance stereo installation, the AT4000 Series is exactly the kind of amplifier we like to recommend: honest engineering, real power, and long-term value.