Musical Fidelity Nu-Vista 3D CD player Page 2
Direct control is via series of small buttons to either side of the drawer/LED stack. On the left are Next, Previous, Language (for discs encoded with CD text), and Power. On the right are Play/Pause, Open/Close, and Stop, below which is a red Error LED. The display offers the usual amenities, as well as a grid that tells you how many tracks the current CD includes. I found that very few discs had text encoding, but when one did, it was cool watching the song titles slide by like headlines in Times Square. Honest.
If you take the time to remove the heavy top plate's 14 snugly tightened hex bolts, you'll be rewarded with scenery worth pulling over for. You'll count two toroidal transformers (and two rather large chokes that look like transformers) and three circuit boards: one contains the power-supply capacitor bank (six caps), one the transport controller circuitry, and the biggest one the upsampling, DAC, and filtering components and the analog output, including the four nuvistors—all laid out like a work of art.
The Nu-Vista 3D's foundation is a smoothly operating transport from Sony, a Burr-Brown 24-bit DAC, and a Crystal Semiconductor CS8420 sample-rate converter chip that upsamples the CD data to 96kHz. But the layout, construction, and circuit design, including the filters, are pure Musical Fidelity, based on MF's research into the sonic and measured performance differences between SACD and CD. The accompanying literature says that MF found that the biggest audible differences between CD and SACD had to do mostly with high-frequency performance, and to a lesser degree with absolute signal/noise ratio and dynamic range, both of which affect high- and low-frequency performance.
To prove its point, the company took a high-quality Sony SACD player and "deliberately altered the HF performance for the worse" while also reducing its signal/noise ratio. According to the press blurb, a panel of seven listeners then preferred MF's A3CD player to the SACD player (playing SACDs, I assume!) by a margin that just reached statistical significance.
From this, MF deduced that, once the SACD player had been so hobbled, the A3CD's sonic performance was either better or indistinguishable. To make a CD player that would sound as good as SACD, MF concentrated its efforts on HF distortion, noise and regulation, power-supply configuration, and internal layout.
Given that SACD's out-of-band problems occur well above 25-30kHz, MF felt it necessary to implement upsampling, which would move digital artifacts out-of-band to at least 35kHz. This allowed the redesign and simplification of the digital and analog filters so that phase shift and group delay were also well out of band, and permitted a reduction in the amount of feedback.
Independently regulated low-noise choke power supplies are used for the 3D's DAC, spindle motor, display, nuvistors, and logic and remote control. Within the nuvistor supply are separate chokes for the high-voltage and heater supplies, which are self-balancing and -regulating to keep the nuvistors operating under optimal voltage conditions. According to MF's literature, the chokes prevent power-supply noise from getting into the circuit and any noise from getting out, thus helping to ensure a high degree of inter-stage isolation.
The small choke regulators (small because small-signal electronics don't draw a lot of current) are PCB-mounted, which saves space and money, but they require the company to invest in the tooling to have them custom-made. Musical Fidelity claims that a choke-regulated power supply yields a better S/N ratio, which leads to increased dynamic range, which results in better resolution.
Particular attention was also paid to the layout and orientation of chokes, transformers, and capacitors in order to eliminate stray fields, which is also why the transport was encased in copper inside the chassis.
The nuvistor stage includes dual-differential class-A amplification and a two-pole passive analog filter network, which MF claims "dramatically reduces" passband ripple effects compared to the A3CD, which uses a seven-pole active, hybrid feedback filter and measures pretty well itself.
According the to the press release, the 3D's output stage is fully complementary, with high current and damping factor, low impedance and feedback, and wide bandwidth, and is capable of producing "huge output voltage, so it cannot be overloaded at any frequency between 4Hz and 150kHz."
"As good as SACD"?
I wouldn't have thought to compare a CD player under review to an SACD player, but Musical Fidelity itself had laid down the gauntlet, and I had the $7500 Marantz SA-1 in-house. To make the test fair, I ran the Marantz and the Nu-Vista 3D into the Hovland HP-100 preamp's standard inputs. The preamp's "purest" input is its tape loop, which bypasses the selector switch. I also used two runs of the same cable, switching between Yamamura Millennium 6000 and Wireworld Gold Eclipse.