Larry Greenhill

The No.331 is the latest iteration in a series of Mark Levinson 100Wpc, solid-state, stereo power amplifiers. Extensive cosmetic alterations, internal structural changes, and new circuit designs make it quite different from the No.27 and No.27.5 models that preceded it. These design refinements emanate from Madrigal Audio Laboratories' latest flagship amplifier, the $32,000/pair, 300W RMS Mark Levinson No.33 Reference.

When I learned that Madrigal Audio Labs was marketing their first integrated amplifier, the Mark Levinson No.383, I felt this was a big change for the Connecticut company. Mark Levinson literally started the high-end marketing revolution back in the early 1970s by manufacturing cost-no-object separate amplifiers and preamplifiers. The purist designs had one overriding rule: employ the simplest circuit path possible. Each amplifier or preamplifier used only individual circuit-board components (no integrated circuits) and had a minimal number of controls, eschewing elaborate switches and tone controls. Mark Levinson Audio Systems and its successor, Madrigal Audio Laboratories, has continued this philosophy of separate components for the past 25 years.

All high-end audio companies turn over their product lines periodically. Even those amplifiers I have depended on as references go out of production. Although my reference amplifier can remain a part of the reviewing sequence, readers won't be able to purchase a discontinued model and get the results I describe. Thus I am compelled to get a review sample of a new amplifier or speaker, and hope for the best.

The $25,000, 500W Mark Levinson No.53 digital-switching reference monoblock amplifier made its regular non-playing appearance at CES 2012 but this time with an illuminated cutaway display, allowing its lead design engineer, Mark Seiber, to walk me through its circuitry. The transparent panel, which the display used in place of heatsinks allowed me to easily see the No.53's four major subsections (analog input stage, modulation, amplifier output stage with its eight air-core inductors, and power supply section, which is at the bottom of the chassis.