Усилители мощности моно — Mark Levinson № 536

The № 536 is a monaural power amplifier from Mark Levinson, the American high-end brand now part of Harman's luxury division. Announced at CES 2015, it replaced the No. 532 and was an entirely new design. Its analogue circuitry is based on the gain stage developed for the preamplifier section of the No. 585 integrated amplifier, combined with a high-speed, high-current output stage.

Key specs that matter

Output is 400 W into 8 ohms and 800 W into 4 ohms, with stability into 2 ohms. Voltage gain is 26 dB. Inputs are one balanced XLR and one single-ended RCA, with input impedances of 60 kohm and 30 kohm. Two pairs of speaker binding posts are fitted. Filter capacitance totals 169,200 uF. Control connections are Ethernet, RS-232, trigger in and out, USB-A and mini USB. The unit measures 197 x 451 x 508 mm (height first) and weighs roughly 45 kg.

Engineering and use context

The amplifier uses Mark Levinson's Pure Path circuit design, a discrete, direct-coupled, fully balanced monaural signal path with no integrated circuits. The architecture is fully differential Class AB, and all the voltage gain and driver stages run in full Class A, while the output devices run in Class AB and stay in Class A for most listening conditions. Each amplifier contains two output stages, one per half of the differential circuit, with 12 bipolar output transistors rated 15 A and 200 W per stage, 24 in total, each with its own driver transistor. The power supply uses eight fast Schottky rectifier diodes and 18 filter capacitors per output stage. A custom low-noise toroidal transformer has separate secondary windings for each output stage, and it is shielded and encapsulated against electrical and mechanical noise. Design targets included harmonic distortion below 0.02% at 1 kHz and 0.2% at 20 kHz, low feedback and high open-loop linearity. The chassis is 6000-series aluminium, machined to close tolerances. The speaker terminals carry Mark Levinson's hurricane wings, which allow cables to be tightened without tools. The network connection allows web monitoring and control. The amplifier is designed and handcrafted in the USA.

Pairing

With its high current and low-impedance stability, a pair of № 536 drives demanding floorstanders and electrostatic panels. The Ethernet, RS-232 and trigger connections integrate with Mark Levinson's No. 526 and No. 523 preamplifiers.

Alternatives

Mark Levinson's № 534 is the stereo power amplifier of the same generation, built on the Pure Path design.