Усилители мощности стерео — Audio Research Reference 160S

The Reference 160S is a two-channel tube amplifier from Audio Research, the Minnesota company that has built tube electronics since 1970. Launched in 2019, it follows the Reference 160M monoblock of 2018 and places the same circuit concept, eight KT150 output tubes and floating GhostMeters, in a single stereo chassis.

Key specs that matter

Output is 140 W per channel continuous from 20 Hz to 20 kHz in Ultralinear mode, and about 70 W in Triode mode. THD at 1 kHz is typically 1% at 140 W and below 0.04% at 1 W. Power bandwidth is 5 Hz to 70 kHz, and frequency response at 1 W is 0.5 Hz to 110 kHz (-3 dB). Input sensitivity is 2.4 V balanced for rated output, giving 25.5 dB of gain into 8 ohms. Input impedance is 300 kohm balanced and 100 kohm single-ended. Output taps are 16, 8 and 4 ohms, the damping factor is about 14 and overall negative feedback is 14 dB. The chassis measures 483 x 260 x 546 mm and weighs 45 kg.

Engineering and use context

Signal handling is balanced from input to output, with four 6H30 twin triodes in the gain stages and four matched pairs of KT150 output tubes. A front-panel switch changes between Ultralinear and Triode operation without changing tubes. An automatic bias circuit, factory set, compensates as the KT150s age, removing routine manual adjustment, and a Tube Monitor mode reports the status of each output tube. The amplifier uses a four-layer circuit board. Two 120 mm low-profile fans in the bottom plate provide forced-air cooling, with switchable high and low speed, and an auto-shutoff function can turn the amplifier off after two hours without signal. Rear handles help move the heavy chassis, and the silver faceplate can be replaced by black to special order. Power consumption is 875 W at rated output, 700 W in Triode mode and 500 W at idle. A switch selects the XLR or RCA input, and a 12 V trigger and RS-232 port support system control. The GhostMeters in front of the tubes offer four brightness levels, including off.

Pairing

The modest damping factor means the 160S works best with speakers of relatively even impedance, and the output taps let the owner choose the best match for each load. The balanced input sensitivity suits Audio Research preamplifiers such as the LS28 or Reference 6SE. The amplifier needs ample ventilation above and around the tubes.

Alternatives

Audio Research's Reference 160M is the monoblock version with the same KT150 output stage in each channel.