More and more audio equipment manufacturers who offer CD players are also beginning to manufacture and sell separate, stand-alone, digital-to-analog converters. What we are generally told is that, although the company's top CD players deliver excellent sound quality, the use of a separate D/A converter will provide an additional small measure of sonic perfection to a system. A stand-alone converter can be linked to any CD player that has a separate digital output. Most will also respond to digital inputs from DAT players or recorders (at 44.1 or 48 kHz) and from digital broadcast receivers (at 32 kHz) such as those available in Europe and Japan.
The Marantz CD-94 player and CDA-94 D/A converter not only are perfectly matched cosmetically, but are intended to work as a pair to provide the "ultimate" in CD playback performance. I did a comparison study between the CD-94 operated alone and the CD-94 and CDA-94 operated as a system. Essentially, this involved two complete lab testing sessions, using the various test discs available for this purpose. Before I get to the results of this head-to-head contest, let me describe the components themselves.
Both the CD-94 and the CDA-94 can be purchased either in a black-satin anodized finish with oak or rosewood side panels or in a rose-gold finish with rosewood side panels.
Up to 20 "blocks" of programming can be memorized by the CD-94, using numeric keys on its front panel or on the supplied remote control. A "block" can be a track number, a track-plus-index number, or a time-into-track number. Shuffle (random) play of all tunes is possible, and Favorite Track Selection, first introduced in Magnavox and Philips CD players, is also featured in the Marantz CD-94. Favorite Track Selection, or FTS, enables you to store track information for a maximum of 226 discs. The number of discs decreases with the number of tracks selected for each disc. For example, if five :racks are memorized per disc, disc capacity of FTS will be 150. If 20 selections per disc are memorized, however, the number of discs that can be handled will drop to 70.
Both optical and coaxial (wired) digital outputs are provided on the CD-94, as well as unbalanced analog outputs.
The CDA-94 D/A converter is equipped with two sets of coaxial wired digital inputs, an optical digital input; digital tape monitoring facilities (for use when listening to a DAT recorder connected to the unit), and a headphone output jack and level control. The converter automatically switches to the correct sampling frequency to match the digital input signal fed to it. The converter has balanced and unbalanced fixed-level output terminals as well as variable-level unbalanced output terminals. Both the CD-94 and the CDA-94 use D/A converters with four-times oversampling and digital filtration. According to Marantz, however, the CDA-94's design further protects signal integrity by using separate circuit boards, power supplies, and power transformers for the digital input-output section, the D/A converters, and the analog amplifiers. This extra care is said to provide a signal-to-noise ratio that is 5 dB better than the CD-94's. The CDA94 also features an "Absolute Phase" switch that can compensate for phase inversion which took place anywhere in the recording chain.
Marantz CDA-94 Control Layout
At first glance, the CDA-94 D/A converter's front panel resembles that of the CD-94. It, too, has a display area and a hinged flip-down panel. The only controls visible when the hinged panel is shut are the power switch and a large rotary volume knob for the variable output terminals on the rear panel. The display area shows which input has been selected, whether the monitor switch is on or off, and which sampling frequency (32, 44.1, or 48 kHz) is currently being converted. A stereo headphone jack and level control are behind the hinged panel, as are switches for input selection, tape monitoring, and "Absolute Phase."
The digital connections on the converter's rear panel include an optical input, two coaxial electronic inputs, and coaxial tape input and output jacks. The analog connections are all outputs, including fixed-level and variable unbalanced outputs and a pair of 600-ohm balanced outputs. A fuse-holder completes the rear-panel layout.
Use and Listening Tests
I listened extensively to the CD-94, operating alone, and was very pleased with what I heard. I have recently acquired a new set of reference loudspeakers, the Infinity RS 9 Kappa units, and I must say that it has taken me awhile to get used to their awesome bass response and somewhat more brilliant high end. All of us tend to get used to our loudspeakers, and when we finally change (and we surely must from time to time, as the state of the art improves), it takes a period of adjustment to become familiar with their "new" sounds. Nevertheless, given some of the most recent CDs in my collection, such as a Telarc recording of Mozart's Symphonies Nos. 25, 28, and 29 (CD-80165) and a Delos recording of Rachmaninoff's Symphony No. 2 (DCD-3071), it was obvious that I was dealing with a good-sounding CD player. Moreover, its many conveniences-such as Favorite Track Selection, shuffle play, and extensive programming facilities-make it one of the more full-featured players that have passed through my lab and listening room recently.
The real evaluation started when I hooked up the CD-94/ CDA-94 combination. All listening tests for this pairing were done using optical coupling between the two units. I selected this method because Marantz and others claim that it will provide audibly better results than a wired digital-to-digital connection. (The same hookup mode had been used for the bench measurements.)
During normal listening, I could not detect any difference in sound quality between the two setups. Oh, every once in awhile, I seemed to think that one or the other sounded better on certain passages of music, but with careful level matching, I found it almost impossible to favor one hookup over the other in an overall sense. There were moments, in the quieter passages of the Rachmaninoff recording, when I felt that the CD-94 alone provided a cleaner, more transparent sound. Switching to the combination, during those same quiet passages, seemed to add a bit of sheen to the string sounds. Though not unpleasant, the string sound did not seem totally lifelike to my ears.
The CD-94 does not boast the linearity of some other high-end players I have tested recently, yet it certainly has many compensating features that may justify its high price.
I'm afraid the same cannot be said of the CDA-94 converter.
If the sample I tested is representative of the full production run, I can see only one reason for spending as much money to own this component as for the player alone: The need for D/A conversion of sampling rates other than the CD's 44.1 kHz. Even so, there are other D/A converters that cost less and do a better overall job. Marantz seems to have batted 500 with this pair.