MBL 9011 Reference Monoblock Amplifier

The MBL 9011 is the most powerful amplifier MBL builds — the Reference Line statement that anchors 101 X-Treme MKIII installations and the largest Radialstrahler systems. Designed as a differential-balanced monoblock, it can also run as a stereo power amplifier in single-ended mode, so a system can begin with one 9011 in stereo and grow to two, or ultimately four, monoblocks without replacing a single chassis.

The 9011 features everything the 9008 A offers — and then some. Three groups of eight output transistors each, eight electrolytic charging capacitors, and a third 400VA toroidal transformer deliver more long-term power output and faster short-term current distribution. The result is up to 50 amps of peak current and pulse output of up to five kilowatts into a 2-ohm load, from a 95 kg (215 lb) chassis. The first watts operate in pure Class A before transitioning to Class AB; MBL's Direct Push-Pull topology and Isolated Gain Cell circuit keep the semiconductors in their linear range under any signal demand, eliminating dynamic compression. Power transistors rest on a vibration-impeding solid copper foundation.

All three toroidal mains transformers can be switched on or off from a rocker switch on the rear — MBL's Silent Reserve fine-tuning. The additional transformers do not change power output, but charge the output capacitors faster and let the amplifier be matched to the room and the speaker's impedance curve. Six in-house-manufactured solid copper terminals support bi-wiring. Handbuilt in Berlin. Hear it at LMC — walk in during business hours at Scottsdale or Tempe, or book ahead for a prepared listening session.