Ejilif: A Wadia 860x and an 861 are 2 different animals altogether. There is a very noticeable increase in resolution and image focus. This is taken directly from Wadia's site:
Available immediately, Wadia has introduced the 1 Upgrade for owners of the Wadia 860 CD Player. A solid affirmation of the advantages of Wadia's modular based architecture the 1 Upgrade allows owner of the Wadia 860 CD Player to realize the full performance of the most current state of the art reference CD Player from Wadia. Here is a description of the new technology included with the 1 Upgrade for the Wadia 860 CD Player:
All New Digital-to-Analog Circuitry --
Based on Wadia 861 CD player and featuring enhanced 24-bit Burr-Brown 1704 DACs, this new circuit incorporates a variety of Wadia technologies, including Wadia Swift Current IC , and improved passive parts in sonically critical locations, representing more than a decade of digital audio development. The result is compelling musical realism.
Wadia Swift Current Technology --
The 1 Upgrade, which will supercede the highly-regarded Wadia 860, is the first to use the companys patented Swift Current IC. This proprietary circuit, first introduced in the Wadia PowerDAC digital amplifier last year, performs the sonically critical current-to-voltage conversion with no negative feedback, resulting in demonstrably superior sound quality.
Conventional digital-to-analog converters perform current-to-voltage (I/V) conversion using feedback circuits based on operational amplifiers. Because the signal from the DAC chip consists of a series of step changes, the distortion introduced by this feedback circuit is a significant limitation on sonic performance.
In contrast, the Swift Current circuit performs this I/V conversion with Wadias patented current-conveyor integrated circuit (IC) that eliminates feedback. This bipolar IC consists of an innovative connection of Wilson current mirrors, an emitter degeneration compensation scheme to optimize transient response and stability, and a novel current mirror arrangement to enhance output impedance.
DigiMaster Up-sampling System Software --
The Wadia 861 CD Player uses the newest version of our patented filtering system with true 24-bit processing. Executed in DSP, the all new software also features user-selectable digital algorithms allowing optimization of sonic performance based on system matching and personal musical priorities. The Wadia 861 software includes the latest version of Wadia's classic DigiMaster time-domain interpolation filter which is optimized to preserve subtle time and phase information critical to music reproduction. Three selectable algorithms are part of a processing system that upsamples* digital information to 1.4112 MHz (DAC sample rate), while differing in time and frequency domain characteristics.
Improved Performance State of the Art Technology --
The performance of the Wadia 861establishes a new standard for all-in-one CD playback systems. The 1 Upgrade for the Wadia 860 CD Player will unveil the richness and magic that make music an essential form of human communication.