Mark Levinson – No 526 Preamplifier

Motherlode of High-End Preamplifiers Features 12 Inputs, Precision Link DAC, Pure Phono, 2x DSD Support, More: Mark Levinson Dual-Mono № 526 Redefines Performance, Features, Sound, and Build

Deemed by Stereophile “a preamplifier to die for” and a Class A Recommended Component, Mark Levinson № 526 dual-mono preamplifier redefines the field when it comes to performance, features, customizability, purity, and build. Handcrafted in the U.S.A., № 526 tips the scales with a total of 12 inputs; the company’s world-class 32-bit Precision Link DAC with three selectable filters and seven power supplies; a Class A Pure Phono MM/MC phono preamplifier; a Class A Main Drive Headphone amplifier; and Clari-Fi music restoration technology. At once practical and luxurious, classic and modern, this reference-grade audiophile component takes music to a higher plane and affords you all the convenience, connectivity, and clarity you deserve. Whether you want to hear vinyl LPs or digital up to DSD 5.6MHz, whether you want to listen through your main speakers or enjoy a more personal experience through headphones, № 526 has you covered.

Mark Levinson’s proprietary Pure Path discrete, direct-coupled, fully balanced, dual-mono signal path and Folded Cascode connections function as internal anchors of the definitive-sounding № 526. If you’ve been seeking to hear music with the kind of purity and accuracy experienced in the recording studio and played back with undetectable coloration, № 526 awaits. It offers degrees of tonality, soundstaging, clarity, and imaging that inspire hyperbole but which must be experienced to be placed in proper perspective.

Managing to achieve unrestricted purity and off-the-charts precision, № 526’s state-of-the-art components suite – including a discrete R-2R Ladder volume control and selectable fourth-order 80Hz high-pass filter for subwoofer integration – teems with complex circuitry, leading-edge engineering, and military-grade build. Everything is hand-selected for a specific task, from the gain-stage JFETs to the tantalum nitride resistors and 6000-Series aircraft-aluminum chassis. It all explains why the objectives of many preamplifiers – high gain, low noise, wide bandwidth, hypnotic linearity – become everyday reality with № 526. 100% Music Direct Guaranteed.

“With its many features, intuitive controls, customizability, textbook engineering, five-year warranty – and jaw-dropping sound, the No.526 is a preamplifier to die for. Strongly recommended, and without reservation.”
– Stereophile, Class A Recommended Component

“$20,000 is getting into end-game audiophile territory these days, but this DAC-PRE earns its price tag with best in class performance, incredible build quality, and ergonomics that elevate it above the pack.”
— HomeTheaterReview, Best of 2018 Award

Unfettered Purity: Pure Path Circuit Design
Since 1972, Mark Levinson has been dedicated to the uncompromising art of sound, guided by the principle of musical purity. To achieve that goal like never before, Mark Levinson engineers scoured company archives and developed a circuit-design philosophy called Pure Path. On a conceptual level, its hallmark principles include a discrete, direct-coupled, fully balanced, dual-monaural signal path that delivers unrestricted, uncompromising purity. Far from merely arranging high quality components in an intelligent manner, Pure Path represents the meeting of science and art – and both measured and subjective performance. Pure Path highlights in the № 526 include Folded Cascodes, an R-2R Ladder volume control, Class A Pure Phono stage, and Class A Main Drive Headphone amplifier output.

Attaining Analog Mastery: The Folded Cascode
Mark Levinson components are designed around a Pure Path amplifier circuit concept that makes heavy use of a circuit design element called a cascode. Originally created for improving the bandwidth of vacuum-tube circuits in radios, cascodes both improve bandwidth and enhance linearity. A cascode combines two transistors so that they operate as a single composite device that functions like a single transistor, using the wanted characteristics of each component transistor, and rejecting the unwanted characteristics. Mark Levinson engineers began their design of the preamp gain stage with pairs of JFETs (junction field-effect transistors) chosen for their low noise and high gain. JFETs achieve such characteristics by being large, and with their size comes nonlinear gain – or distortion. To mitigate this, BJTs (bipolar junction transistors) are added to the circuit. BJTs exhibit very low input impedance and very high output impedance, which translates to excellent bandwidth and linearity. By creating a cascode of the JFETs and BJTs, Levinson engineers created a design with the best characteristics of both sets of devices. The output of the cascode is then connected to another transistor of the opposite “gender.” Current flows through it in the opposite direction to “turn around” the direction of the signal current. This special connection is called a Folded Cascode and a hallmark of the Pure Path circuit: High gain with low noise, wide bandwidth, and excellent linearity.

Pure Phono: Class A for a Classic Medium
Preamplifying from turntable to line level can a difficult task, and is an area where some equipment makers skimp on components and design. № 526 features Pure Phono, itself following Pure Path design principles including discrete design free of op amps. Pure Phono operates exclusively in Class A throughout, employing tantalum nitride thin-film resistors and polypropylene capacitors with punishingly low tolerances. Pure Phono also contains physically separated channels and balanced inputs for purity. In № 526, Pure Phono offers a fixed-gain MM section with five capacitive cartridge-loading settings, and an MC section with three gain settings and 10 resistive cartridge-loading settings. And an ultrasonic filter intelligently compensates for rumble and warping.

A Mark Levinson Hallmark: The Precision Link DAC
The Mark Levinson Precision Link DAC transforms digital data streams into analog audio art. It combines unique Pure Path engineering design approaches with painstakingly selected components to deliver impeccable performance than can be appreciated both on the test bench and in the listening room. The converter chip comes from ESS Technologies, known for jitter-elimination circuitry, and resynchronizes incoming data to its own extraordinarily stable clock. Combined with its 32-bit resolution, the low-jitter stream reduces distortion and noise, allowing remarkable retrieval of ambient detail that other DACs miss. The Precision Link DAC operates the converter’s outputs in current mode, where they are fed into a fully balanced current-to-voltage (I/V) converter that provides the exact signal level desired. Maintaining near-zero voltage keeps the current sources virtually immune to nonlinearity, maximizing bandwidth and minimizing distortion. Common-mode noise and distortion are cancelled in this mirror-imaged, differential configuration, resulting in a pristine signal with a vanishingly low noise floor. A unique power supply configuration – five independent power supplies operate the converter chip alone, and individual linear power supplies for the left and right channels power the discrete I/V and antialiasing filter circuits – further advance the reference performance.

Get Personalized Performance with Precision Link DAC Filters
The Precision Link DAC performs oversampling and digital filtering of digital audio data, increasing the effective sample rate by filling in additional data points between the actual data present, which in turn reduces the demands on the low-pass (antialiasing) filter required on the analog output of the converter. Three digital filter options are available in the Mark Levinson Precision Link DAC. The Fast filter has a steep roll-off for maximum attenuation of unwanted high frequency information. It offers the best noise and distortion measurements. The Slow filter has a gentler roll-off of high frequencies and exhibits less pre- and post-ringing on transients. The Minimum Phase filter has a steep roll-off of high frequencies. These filters are selectable because there is no one correct choice. Some listeners are sensitive to pre-ringing on transients and believe it sounds unnatural. A digital filter with pre-ringing exhibits excellent frequency response behavior precisely because of its transient behavior. Other listeners might be more sensitive to the relatively long period of ringing exhibited by the Minimum Phase filter and therefore would prefer the Fast or Slow filter. More likely, listeners will prefer different filters with different genres of music, and they have that option with № 526.

Teeming with Flexibility: Stocked with Pure Path Digital Inputs
№ 526 offers six digital inputs for system flexibility. One Balanced AES/EBU (XLR) input and two Coaxial (RCA) inputs use high-speed differential receivers to reject noise and provide clean digital waveforms to the Cirrus Logic digital audio receiver chip. Two additional Optical (Toslink) receivers directly drive the digital audio receiver. For direct connection to a computer, № 526 also offers an asynchronous USB Type-B input built around a CMedia USB audio processor chip. Using the high-speed USB 2.0 standard, the CMedia chip reliably and accurately receives audio data over USB in up to 32-bit/192kHz PCM or in native DSD format at up to double speed (5.6MHz. The CMedia chip transfers USB data asynchronously. It gets as much data as possible as and when it is available, rather than transferring the data in sync with the music playback, which reduces demands on the computer and instead allows the processor chip to precisely control the flow of data to the DAC.

A Superior Volume Control: R-2R Ladder
The analog potentiometer – a device with a number of performance drawbacks – is the basis of many volume controls. For starters: The mechanical connection wears out, creating scratching or crackling noises. It is nearly impossible to manufacture an identically performing pair, and mismatches in a stereo pair can cause level imbalances between the two channel. And, due to their varied reaction to parasitic capacitances at different volume settings, the sound changes depending on where the volume is set. Rather than attempting to improve upon this flawed design, Mark Levinson engineers abandoned it and employed a complex circuit architecture called an R-2R Ladder. In the R-2R Ladder, a string of resistors with identical resistance (R) form the side of the ladder, with another set of resistors forming the rungs, all identically with double the resistance (2R). This unique circuit takes whatever current appears at its input and successively divides it in half at each “rung” of the ladder. Different combinations of “rung” currents can then be selected and added together, precisely delivering nearly any output current, and thereby, volume setting. The currents through the rungs are determined by fixed resistors, capable of very tight tolerances, able to be closely matched to one another in value. Analog switches “steer” the currents, are precision devices, and have no mechanical contacts to wear out. In short, the R-2R Ladder solves all the problems inherent to potentiometer-based volume controls.

No-Compromise Build: Military-Grade Components
All Mark Levinson equipment employs electronic components carefully chosen for their specific task. Gain-stage JFET pairs have high gain, low noise, and low distortion. And since they are encapsulated in the same package, the two devices operate under nearly identical conditions. Capacitors used in critical filtering locations are film types, noted for their consistent performance regardless of temperature and frequency. Finally, resistors in critical gain-setting and feedback locations use tantalum nitride thin-film elements. Tantalum nitride typically finds use in sensitive military equipment because it is unusually stable with respect to temperature, exhibits very low noise, and is unaffected by magnetic fields. In fine audio equipment, those characteristics make the sound more revealing and effortless, free of the low-level nonlinearities caused by lesser resistive materials as they heat and cool under dynamic conditions.

Clari-Fi Music Restoration Technology Defeats Compression
Clari-Fi music restoration technology analyzes compressed digital audio files during playback in real time and reconstructs much of what was lost in the compression process. The complex Clari-Fi processing algorithm is implemented on a powerful Analog Devices SHARC DSP. Unlike simple equalization, Clari-Fi continuously and automatically adapts the amount of reconstruction it performs to the degree to which an audio file has been compressed. № 526 offers an Intensity control, enabling fine adjustment of the amount of reconstruction applied to the signal – or bypass, if preferred.

Loaded with Connectivity: Completing the Signal Path
№ 526 offers five line-level analog inputs: two balanced (XLR) and three single-ended (RCA) in addition to the Pure Phono (RCA with grounding pin) input. The preamplifier delivers its signal to balanced (XLR) and single-ended (RCA) stereo outputs, as well as a 1/4-inch (6.3mm) Main Drive Headphone output integrated into the front panel. The Main Drive Headphone amplifier circuit drives up to 32-ohm headphones in Class A by employing the main output circuit rather than a secondary signal path. A selectable fourth-order, 80Hz high-pass filter enables seamless integration of a single or dual subwoofers for full-range performance with a wide range of loudspeakers. System-integration connectivity includes Ethernet/IP control, RS-232, USB for monitoring and configuration via web page, plus 12V triggers and an IR input. An included machined metal remote delivers the robust feel and precise control befitting of a component of the preamplifier’s caliber.