Burmester 159 Amplifier (pair)

Burmester spent seven years on the 159 and calls it the most powerful amplifier it has built. Each unit is a single channel in full-bridge configuration, operating in class A/B, with the input and voltage-gain stages built from Burmester's X-Amp modules; the same input topology was later carried down into the 218 and 216. The published figures describe an amplifier designed around current rather than wattage: 1,200 W into 4 Ω under the IEC 62368-1 continuous rating, 2,500 W on CEA pulse testing, 17 A continuous and 70 A peak output current, 0.0009% THD+N at 50 W and an unweighted signal-to-noise ratio above 116 dB at full power. The feature that sets the 159 apart from every other Burmester amplifier is an adjustable damping factor, set by a rotary encoder on the rear panel, which lets the owner tune the amplifier's grip on the loudspeaker to the speaker and the room. The control electronics are hidden beneath an aluminum cover so the front shows nothing but the chrome panel, and all sound-relevant components are sourced from German manufacturers.

Each 159 takes more than 100 hours to build. Circuit boards are assembled by hand, transformers are selected, and the finished amplifier goes through several days of trial runs on a computer-aided measuring station before a final listening test. Robert Harley reviewed the 159 for The Absolute Sound in late 2022 and opened by saying that "everything about Burmester's flagship 159 monaural power amplifier is extreme," adding that it is something you have to see firsthand to appreciate. Burmester's own account is of power and control reaching levels it had not measured before, with the Burmester character of spatial resolution and warmth intact; because the damping factor is adjustable, the final balance between control and ease is partly in the owner's hands.

A pair of 159s is meant to stand beside the loudspeakers with the shortest practical speaker cables, fed over long balanced runs from a Reference Line preamplifier such as the 808 MK5 or 077, with the 111 Musiccenter or 257 turntable as source. In Burmester's own Signature system the 159 drives the BC350 loudspeaker, and it is a natural match for the largest Wilson Audio, Magico and Sonus faber designs we carry. The 909 MK5 below it is a stereo amplifier that can be bridged to 1,930 W; the 159 is a monoblock from the outset, with roughly half the distortion and a much larger current reserve.

The 159 is the only amplifier in Burmester's Signature Line. Each measures 21 inches wide, 16 inches high and 26 inches deep and weighs about 396 lb, so placement, flooring and electrical supply need to be planned before delivery.