ATI Signature Series are fully balanced, differential amps, advanced from previous designs which were essentially balanced bridged amplifiers. Signature Series uses only a single input stage with dual-differential output stages. This design approach retains the advantages of balanced designs and reduces noise by 50%. Using current feedback rather than voltage feedback, Signature Series amps respond faster with a virtually unlimited slew rate which makes them capable to reproduce todays best music and film sound.

ThermalTrak™ output devices are incorporated in Signature Series amps to provide an integrated device for temperature sensing with the output transistor resulting in real-time bias performance. Combining these advancements with dual DC servos reduces DC offset at the output to insignificant levels.

The use of a modular PCB layout with amplifier and power supply parts on the same card with edge to edge isolation of AC and signal input provides improved signal-to-noise ratio. Dual toroidal transformers, dual power switches and dual AC power cords bring a complete dual-mono design to the AT4002 and AT6002. Multi-channel amplifiers up to the 7-channel AT4007 and AT6007 models may be connected to independent 20 amp circuits for greater sustained output power than would be possible than from a single AC circuit.

4000 Series amps are rated at 200 Watts RMS from 20Hz to 20kHz with no more than 0.03% THD at 8 ohms with all channels driven and 300 Watts RMS at 4 ohms under the same conditions. Signal-to-noise ratio is typically -126dB referenced to full output so that each Signature Series amp is capable of playing back the full dynamic range available on today’s lossless recordings.