Power amplifiers mono — Boulder 1151

The 1151 is a mono power amplifier from Boulder, built with an extraordinarily wide bandwidth and exceptional measured performance. The 1151 brings Boulder's most accomplished current engineering to dedicated monoblock power amplification.

Key specs that matter

Input impedance is 200k ohms balanced or 100k ohms single-ended. Output power is a substantial 350W into 8 ohms, doubling cleanly to 600W into 4 ohms - a textbook power doubling indicating a robust, well-regulated power supply. Gain is 26dBu. Frequency response spans an extraordinary 0.015Hz to 150,000Hz within plus-or-minus 3dB - a remarkable bandwidth extending far beyond conventional audible range. Total harmonic distortion plus noise is 0.002% at 1kHz, rising to 0.01% at 20kHz into 8 ohms. Weight is 24.5kg, reflecting Boulder's uncompromising build standards.

Sound and use context

Expect substantial power delivery combined with exceptionally clean measured performance reflecting the sub-0.002% distortion at 1kHz, combined with the extraordinarily wide 0.015Hz-150kHz bandwidth, representing Boulder's most accomplished current monoblock engineering ambition.

Pairing

The clean power doubling into 4 ohms suits a wide range of loudspeaker impedances, and Boulder's own 1110 preamplifier shares the brand's coherent engineering philosophy.

Alternatives

Boulder's own 861 offers a stereo alternative within the same broader amplifier catalogue for buyers wanting a two-channel configuration instead.