Усилители мощности стерео — Boulder 1162

In the 1100 Series, the 1162 is the bigger stereo power amplifier of Boulder Amplifiers, a company founded in 1984 that still carries out all design, engineering and manufacturing in-house at its facility in Louisville, Colorado. Within the 1100 range it sits beside the 1151 mono amplifier, the smaller 1163 stereo model, the 1110 preamplifier and the 1108 phono stage, and its machined front panel depicts the topography of Flagstaff Mountain near Boulder.

Key specs that matter

Boulder rates the 1162 at 300 W continuous per channel into 8 ohm. Peak figures are 450 W into 8 ohm, 900 W into 4 ohm and 1,000 W into 2 ohm. THD is 0.002% at 1 kHz into 8 and 4 ohm, rising to 0.01% at 20 kHz, and 0.003% into 2 ohm. Equivalent input noise is 2.2 microvolts over a 20 kHz bandwidth, and the magnitude response deviates by no more than 0.04 dB from 20 Hz to 20 kHz, with -3 dB points at 0.015 Hz and 150 kHz. Voltage gain is 26 dB. Input impedance is 200 kohm balanced and 100 kohm unbalanced. Maximum consumption reaches 3,000 W, with 120 W at idle and 10 W in standby, and the amplifier weighs 61.2 kg.

Engineering and use context

Boulder applies Class-A Smart Current biasing to the output stage, a fast bias adjustment scheme that keeps idle dissipation far below that of a conventional class A design. Two power transformers are DC filtered and housed in a welded steel case. The 1162 is direct-coupled, with a servo that zeroes DC offset from the source, and a protection circuit disconnects the loudspeakers if input DC reaches a harmful level or a speaker cable is shorted. A clip detector turns the front LED red, and a thermal cutout mutes the output when transistor cases reach 70 degrees C, releasing it at 60 degrees C. An ARM supervisor controls the power-up relays that handle the inrush of the large toroidal transformer, and its Ethernet link brings software updates plus IP and HTML control. A 32 A IEC power cord comes supplied, and Boulder asks for at least 8 cm of free air around the chassis.

Pairing

Inputs are balanced XLR only, so an unbalanced preamplifier connects through an RCA-to-XLR cable or the Boulder ABL2 adapter. Four pairs of 6 mm binding posts accept spade terminals for bi-wired loudspeakers, while banana plugs are not supported. Boulder Net links the 1162 with other Boulder components and networked home systems, which makes the 1110 preamplifier the matching partner from the same series.

Alternatives

The Boulder 1163 is the compact stereo sibling, with half the continuous power and less than half the weight.