California Audio Labs Icon Mk.II Power Boss CD player
Hard-core analog geeks such as myself prayed that this activity meant that vinyl would return as a major market force. Alas, vinyl today is as much a niche medium as open-reel (a far superior format to vinyl, I feel) was in the 1960s. Moreover, technological improvements over the last decade have made high-end audio a much higher-resolution medium. As a result, while the sound quality of CD has grown closer to that of LP, today's playback gear has made the remaining differences easier to perceive.
The Power Boss
One of the factors bringing CD sound closer to what it should be is HDCD. The Power Boss upgrade for the California Audio Labs Icon Mk.II not only adds HDCD capability to the basic CD player, but upgrades other circuitry as well. The 18-bit Burr-Brown PCM61P DAC set has been replaced with two Burr-Brown PCM1702 DACs, a higher-performance 20-bit package. CAL claims that this chipset improves the measured S/N ratio and dynamic range of the player, as well as reducing distortion. In addition, the '1702 employs "Sign Magnitude Architecture," which, according to CAL's literature, uses two matched, inverted "mirror-image" DACs that "allow for smaller amplitude steps than previous multi-bit configurations, eliminating unwanted glitches and other linearity errors around the critical bipolar zero point, from which the amplitude steps commence."
The Power Boss is available to all current owners of Icon and Icon Mk.II CD players (footnote 1). It includes six separate power supplies, four of which are three-stage regulated power supplies. Each of these includes a 1-farad capacitor for improved voltage stability. The Power Boss also employs a synchronous system clock, which CAL claims removes timing error or jitter.
Furthermore, the Power Boss circuit board is pre-prepped for an EEPROM serial-port interface, currently under development at CAL. This will permit user adjustment of certain parameters of the dither modes via personal computer. In addition, future upgrades to the HDCD decoder's software can be done via downloading from computer.
The ole, trusty Icon
First, a bit about the stock Icon Mk.II. In 1993, devastated by the disappearance of vinyl, I was seeking a one-box CD player to use as a primary reference for new CD releases. The price had to be under $1000; I wasn't sufficiently committed to the medium to want to spend more than that. A sample of the CAL Icon Mk.II arrived for me to review for The Abso!ute Sound (footnote 2). I was mightily impressed.
Yes, the player had quite a few colorations, most notably a warm and bloated midbass, a powerful but somewhat loose bottom end, and a forward midrange that was quite noticeable on vocals and woodwinds. It was not the last word on detail resolution or ambience retrieval, and its top octave did not sound that extended. But those caveats aside, it was a tremendously musical player, which I could listen to for hours on end, and it was sufficiently revealing to become my primary digital reference front-end for reviewing equipment and music on my "affordable" system.
To my surprise, I was still enjoying the player in spring 1995 as much as I did when I first heard it. Moreover, when I listened to the unit again for comparison for this review, I realized my original enthusiasm remained, even though there were obvious differences between the original and upgraded units. I applaud California Audio Labs for producing a player for under $1000 that can still impress five years after its release.
The associated equipment for this review included a Creek 4240 Special Edition integrated amplifier driving the Acarian Systems Alón Trio System (Petite speakers and PW-1 stereo passive subwoofer). Interconnects were MIT Terminator 2 and speaker wire a tri-wired Acarian Systems Black Orpheus configuration.
As the Power Boss upgrade includes circuitry beyond the HDCD decoder (and thus it is impossible to separate the sonic differences created by the HDCD filter circuitry from those of the additional upgrades), I auditioned the Icon with a wide range of nonHDCD recordings. I also compared the unit to a stock Icon Mk.II without the upgrade. To judge its HDCD performance, I used all of the Winston Ma Golden String CDs, the HDCD/non-HDCD comparison tracks on the Reference Recordings HDCD Sampler 2 (Reference Recordings RR905CD), and Emmy Lou Harris's Wrecking Ball (Elektra/Asylum 61854-2).
Is it really the boss?
The areas of greatest weakness in the original Icon Mk.II are those of the Power Boss upgrade's greatest strengths:
Neutrality: Whereas the original Icon Mk.II was replete with colorations, the Power Boss unit is one of the most neutral-sounding digital players I've ever heard. Vocals were particularly captivating. Robin Holcomb's voice on Rockabye (Elektra/Musician 961289-2) was presented with silky and seductive realism, as was Emmy Lou Harris's on Wrecking Ball, despite producer Daniel Lanois's considerable use of processing.
Footnote 1: The Icon was reviewed for Stereophile by Guy Lemcoe and Robert Harley in April 1990 (Vol.13 No.4, p.159), with the Mk.II version reviewed by Jack English and Thomas J. Norton in July 1992 (Vol.15 No.7, p.135).—John Atkinson
Footnote 2: My review didn't air in The Abso!ute Sound until Issue 101, published in the spring of 1995.—Bob Reina