Welcome

For years Boulder has built the world’s

finest high-powered, high-performance

amplifiers, amplifiers whose power

output required substantial and heavy

casework to contain all of the

electronics inside. In every one of

these cases, these amps also needed

a heavy wooden crate for transport, a

large, obtrusive power connector, and

multiple people for installation.

When we were asked to create an

amp that could be shipped in a carton,

carried by a single person, and

installed in a shelf or cabinet without

any decrease in musicality, we gave it

a lot of thought.

And then we did it.

Basic Architecture

Physically, the 1161 is the smallest

amplifier in the 1100 Series and comes

in at 150W per channel, half the power

output of the larger 1160 Stereo

Amplifier. As a member of the 1100

Series, it is also fully-balanced and

includes the equivalent circuitry and

functional features of its larger siblings.

The chassis is cut from solid slabs of

metal, there are a host of external

control options, all types of active

protection are in place, and power is

substantial and conservatively rated.

Power Where it’s Needed

One could initially assume that cutting

the power output in half would mean a

marked drop in dynamics and control

for the 1161. This is most certainly not

the case. While the amplifier’s 150W

Basic Design

continuous power output is half that of

the larger 1160, it is still a Boulder. All

of the control, neutrality, and detail are

there. A new transformer design and

current limiting circuit have given the

1161 capabilities far beyond what is

expected from 150W. Other than

limitations in absolute maximum output

level, the 1161 is perfectly at home

with any of its 1100 Series stable

mates.

The key to control of a loudspeaker

while remaining clear and transparent,

regardless of the delicacy or

complexity of the audio signal, is the

ability to deliver undistorted power from

a noise-free background into any

reasonable load. The 1161

accomplishes this with a combination

of balanced inputs and outputs to

reduce noise to vanishingly low levels

and more output devices than are

typically found in a 150W amplifier.

The 1161’s extremely low output

impedance makes it non-reactive

regardless of how the speaker’s load

changes during playback. This

guarantees that the 1161’s character

will never change, regardless of what

you connect it to.

The output section also makes use of

multiple smaller, faster filter capacitors

instead of fewer larger, slower caps to

deliver prodigious and dramatic

dynamic impact. As in all other 1100

Series products, Boulder’s 983 gain

stage is featured and is capable of

pushing substantial current swings into

the output section whenever

necessary without flinching. Even

small details like a new bias circuit

based on output to eliminate the

manual bias setting at the factory

mean that the amplifier is always

optimized regardless of use or age.

The 1161 has a new feature, however,

that sets it apart: It’s the first amplifier to

take advantage of a new current

limiting circuit. Current limiting senses

current through each output device,

operating on a governor. It is generally

used for protection to keep the

amplifier safe by shutting down the

outputs in the event of a short or a

crossed speaker cable. Boulder’s

engineers theorized that this same

circuit could be used to manage

maximum power during very high

output and demanding passages of

music. By adjusting the way the circuit

operates and relaxing the time limits

that it will allow from the amplifier for

very short durations, extreme power

outputs can be achieved without any

additional distortion. Cleanly executed

dynamics or explosive transients in

music or film scores are easily taken in

stride by the 1161.

What does all this technical info mean

to you? Other than achieving ultimate

loudness, the 1161 runs neck and

neck with Boulder’s larger amplifiers

and won’t get between you and the

way your music collection was

recorded.

Available Technology

Technology should make things easily

accessible when needed but be out of

the way when not. The 1161 is

perfectly at home in a stripped-down,

less-is-more, two-channel setup in the

heart of a music lover’s system. A 12V

Basic Design

trigger port is available for straight-

forward theater systems or automatic

turn-on with a Boulder preamplifier. Yet

complete IP control capability is also

available to connect it to an integrated

cinema or smart home’s network for

fully-automated control and monitoring.

There’s even a USB port for software

updates. Because all of this operates

through the amplifier’s built-in ARM

system controller, it’s incredibly flexible

for those who will need it and invisible

to those who won’t.

Mechanical Design

Every panel in the 1161’s casework is

precisely carved from solid blocks of

aluminum and damped during

assembly to prevent mechanical

resonance from affecting the audio.

We’ve also potted, canned, and

damped the transformer to prevent

any mechanical hum or vibration from

interfering with your enjoyment of the

music passing through. It should be

evident by now that no shortcuts were

taken when it came to developing the

smaller 1100 Series amplifier.

The Truth is in the Listening

Every song played through the 1161 is

a personal expression and every film

soundtrack is a way to put you in the

center of the action. Likewise, there

are songs of incredible intimacy and

cinema features of intense drama. The

1161 was created to let you hear and

feel everything the performers wanted

without any size, connection, or

installation limitations.

It’s time you had it all.

Technical? Specifications

Peak Power? 450W, 2 ohms

Continuous Power? 150W, 8, 4, 2 ohms

Inputs 3-pin XLR

Outputs? 0.25-inch (6mm) wingscrew

Input Impedance? Balanced: 200k ohms,

Unbalanced: 100k ohms

Voltage Gain? 26 dB

Equivalent Input Noise (EIN), 20 kHz, BW? 1.5 μV

Magnitude Response, 20 Hz to 20 kHz +0.00, -0.04 dB

Magnitude Response, -3 dB at 0.015 Hz, 150 kHz

Common Mode Rejection (Balanced only)? 60 Hz: 90 dB, 10 kHz: 70 dB

Crosstalk, L to R or R to L? -100 dB or better, 20 Hz to 20 kHz

Power Requirements? 100, 120, 200, 240 VAC, 50-60Hz

Power Consumption? 100W nominal, 1000W maximum

Amplifier Dimensions 18” W x 16.43” D x 7.2” H

45.7 cm W x 41.7 cm D x 18.3 cm H

Amplifier Weight? 54 lbs. (24.5 kg)

Amplifier Shipping Dimensions 24” W x 23” D x 14” H?

61 cm W x 58 cm D x 36 cm H

Amplifier Shipping Weight? 64 lbs. (29 kg)