I am the original owner; this No. 51 is in very good condition and has very low hours, all original accessories, remote and boxes/packing are included. It has just been checked out from top to bottom by the Mark Levinson service center United Radio in East Syracuse, NY.
Power Supply: The power supply is the foundation upon which the audio and video signals are built. The analog audio outputs utilize a dedicated power system consisting of a custom-designed low-noise toroidal transformer, a secondary analog power section which performs the
first stage of regulation and filtering, followed by a final stage of local regulation in the output section itself.
Power to the digital audio and video sections is provided by a switch-mode power supply that delivers a single constant voltage, which is distributed to local modules where it is converted to the voltages required for each individual circuit. This “point of load” power distribution technique prevents unwanted interactions, caused by uneven supply, during periods of high demand from any single circuit. Another advantage is the efficient distribution of power reducing thermal dissipation to provide a more stable operating environment.
Video: Custom calibrated scaling and de-interlacing are provided with support for resolutions up to 720p and 1080i. Other features include:
• Aspect ratio conversion to eliminate letterboxing and pillar boxing.
• High quality 14-bit / 216MHz video Digital-to-Analog Converters (DACs) provide exceptional video output for analog displays.
• An on-screen display, unique to the Nº51, complements the elegance of its industrial design.
In addition to the standard analog video outputs, the Nº51 includes a High-Definition Multimedia Interface (HDMI) output for use with digital display devices
Audio: The Nº51 employs a Direct Digital Synthesis circuit incorporating a very high frequency reference clock. All data and clock signals carrying the digital audio information to the DACs are sent via a balanced Low Voltage Differential Signaling transmission line. This transmission scheme was first utilized in the Nº40 Media Processor and Nº390S CD Processor. The Nº51 also has the ability to output 44.1, 48, 88.2, or 96kHz signals from the S/PDIF, AES or EIAJ outputs using a dedicated sample rate converter.
Digital-to-analog conversion in the Nº51 is implemented using balanced multi-bit Sigma/Delta DACs delivering superb technical performance. In addition to the multi-bit architecture, these DACs have a differential current output, which allows optimization of the critical current-to-voltage conversion stage with dedicated operational amplifiers, possessing superlative rise time and bandwidth characteristics. Each channel incorporates two DACs in a dual-mono mode configuration. Following this, a custom active filter circuit sums both halves of the balanced signal and provides excellent common mode noise rejection in addition to outstanding audio characteristics. This approach to the digital-to-analog circuit topology yields extraordinarily low distortion, improved signal-to-noise ratio and superb, musical sound quality.