Digital Processor Reviews

By all means, reread Fremer's review of the Nu-Vista 3D in last October's issue. Mikey preferred the sound of SACDs played on a Marantz SA-1 SACD player to the sound of CDs through the Nu-Vista 3D. But he found that the 3D did a better job than the Marantz with regular CDs.

Here's how the argument in favor of buying a CD player goes: There may not be much software yet, but more is coming soon. So why not buy an SACD player mainly for playing CDs and have the SACD capability?

Seems like a good argument. Is it?

No one disputes that SACD players do a more than adequate job of playing "perfect sound forever" CDs. But do these SACD players maximize the performance of CDs to the extent that the Musical Fidelity Nu-Vista 3D does...or the new Musical Fidelity A3²⁴ processor? If you want to get the most performance from your CDs, should you forgo SACD capability? That's the question.

At $4995, the Nu-Vista 3D CD player is a limited-edition product. Antony made only so many and he's not making any more. If you want one, better buy one now or lose your chance. Or, if you're like me, do digital on the cheap and buy his A3²⁴ D/A processor for $1195. Hang on to most of your money and keep your present CD player.

The A3²⁴ borrows its design and many of its parts from the Nu-Vista 3D. But it doesn't use nuvistors in the analog output stage and it's not a limited edition.

"Look," said Antony at lunch the other day, "we're not saying that CD is absolutely as wonderful as SACD, but it's bloody near. The A3²⁴ is available now and it will work with the CD player you've got. Don't throw away your player. Don't throw away your discs. In fact, buying the A3²⁴ will be like buying a whole new CD library, for only $1195."

There's no quelling Antony's enthusiasm. He told me that the A3²⁴ is the best processor he knows how to make, regardless of price. "If I built it to a higher price point, there's very little extra I would do with it," he said.

Here's what you get for your $1195: You get a processor that increases the word length to 24 bits. Like the Nu-Vista 3D, the A3²⁴ uses Crystal Semiconductor's CS8420 sample-rate converter chip to upsample to 96kHz. An additional chip provides further upsampling to 192kHz.

Why the two upsampling rates?

With some digital sources—most notably those with Sony transports—the A3²⁴ sounds better upsampled to 96kHz, says Antony. But with other players the processor sounds better upsampled to 192kHz. Michaelson knows of no explanation for this—but it's true, as I heard myself. The Rega Jupiter uses a Sony transport mechanism, and I preferred 96kHz. But with my Denon DCD-1650 I thought that 192kHz provided more space, more air, and greater subjective dynamic range. When you're dealing with digital, some of the stuff is voodoo.

Antony, in his exuberance, suggests that any old CD player with a digital output will serve as a transport. After all, as part of the upsampling process, the A3²⁴ reclocks the incoming digital datastream, suppressing jitter.

But I'm not sure things are that simple. Some transports might sound better than others, even if not dramatically so.

First, as Antony admits, a coaxial RCA connection provides better sound than the optical TosLink connection. (Some cheap players, especially changers, have only a TosLink digital output, so the A3²⁴ includes a TosLink input.) And, as I found with the Rega and Denon players, inserting a Monarchy Audio 24/96 Digital Interface Processor into the chain improved the sound. One of the things the DIP does is reclock the digital datastream. Why should the Monarchy DIP make the sound even more dynamic and less edgy when the Musical Fidelity A3²⁴ itself reclocks the datastream? Perhaps reclocking twice doesn't hurt. I don't consider the Monarchy DIP essential with the A3²⁴, but it helped.

The big advantage of upsampling is that digital distortion and noise are pushed well out of the way—above 30kHz. So the digital and analog filters can be shoved out of band, too, minimizing phase shift and group delay. (In simple terms, phase shift wrecks spatial reproduction, while group delay ruins harmonic reproduction.) Phase shift and group delay are why conventional CDs often sound airless and harsh.