Amplifier Technologies Adds 4000 Series Available with two to seven channels, these amps share the design philosophy of the company's 6000 series.RS Staff ⋅ Nov 8, 2015 Amplifier Technologies has added the new 4000 series amplifiers to its lineup. Available with two to seven channels, these amps share the design philosophy of the company’s 6000 series. All amplifiers in the 4000 series are rated at 200 Watts RMS from 20 Hz to 20 kHz 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. The signal-to-noise ratio is typically 126 dB referenced to full output so each amplifier in the series is capable of playing back the full dynamic range available on today’s lossless recordings. All amplifiers in the company’s range are available in standard (17-inch) and rack-mount (19-inch) chassis with domestic (117V) or export (220 to 240V) chassis.