like most CD players, the Marantz unit has a PAUSE button that instantly interrupts play, which resumes at the same point the next time the button is pressed. Buttons marked REv. and F.F. slew the laser pickup back or forward while they are held in. In this mode, however, there is no audio output and no indication of pickup position other than the amber light designating the track being scanned.
The programming controls of the Marantz CD73 are located under the display window. They can be set to play or to omit any of the tracks on a disc, to a maximum of fifteen. The amber light corresponding to any track can be lit by pressing the SELECT button from one to fifteen times, and pressing PRESET enters that selection into memory (its green track -number light remains on to show that it has been programmed). Alternatively, the CANCEL button can be used to delete a selection from the program (extinguishing its green LED).
After the player has been programmed, pressing NEXT PROGRAM/PLAY starts the playback sequence. The disc turns and the amber lights advance sequentially to the first programmed track, which is then played. The playing sequence follows the programmed pattern until the last selection has been completed, after which the unit shuts off. At any time, pressing STOP/ALL CANCEL cancels the programmed sequence and stops the player. Pressing REPEAT causes all programmed tracks to be repeated indefinitely until the button is pressed again.
Much of the rear apron of the Marantz Marantz CD73 is occupied by a heat sink and a portion of the unit's power transformer that extends from the chassis. In addition to the gold-plated signal -output phono connectors (meant to feed a line -level amplifier input), there are two phono jacks marked rather cryptically IN (REMOTE) and EASY (OUT). These are intended for use with an optional remote -control accessory that the company plans to introduce later.
Our test procedure for the Marantz Marantz CD73 was essentially the same as that used for the eleven CD players we tested for the July 1983 issue. The operating features and test results are summarized in the accompanying box using the format established in that issue, which we plan to follow in future reports on CD players. We were not always able to use the full capabilities of the standard Philips and Sony test discs, however, for these discs have from thirty-six to thirty-nine distinct tracks, and the Marantz CD73 has no easy means of selecting tracks numbered higher than fifteen. (It is possible, though very time consuming, to reach tracks numbered above fifteen by repeatedly pushing the NEXT PROGRAM/PLAY button.)
The Marantz CD73's (fixed) output level from a 0 -dB, 1,000 -Hz test tone measured 2.12 volts, with the channel levels matched within 0.12 dB. The frequency response, identcal for both channels, showed a slight cyclical variation above 2,000 Hz, but the overall level fluctuation of +0.1, -0.2 dB from 20 to 20,000 Hz was certainly negligible. The unweighted signal-to-noise ratio (S/N) relative to the player's maximum output at 1,000 Hz was 104 dB, and the A - weighted S/N was 114 dB. Both figures are outstanding.
The 1,000 -Hz harmonic distortion for recorded levels from 0 to -24 dB was measured using the Philips TS3 test disc (catalog number 410 055 2). We found it to consist of a number of harmonic components, all at very low levels (typically from -90 to -100 dB). All significant harmonics up to the ninth were included in our measurement. The distortion was in the range of 0.0044 to 0.0052 per cent at recorded levels from 0 to -6 dB, rising slightly to 0.0089 per cent at -12 dB and to 0.011 per cent at -24 dB. Distortion readings could not be made at lower recorded signal levels since the low-level distortion products were masked by system and test -instrument noise. It should be noted that the relatively "high" 0.011 per cent reading at a -24 -dB level corresponds to -103 dB referred to the 0 -dB level, or 0.0007 per cent as we usually measure distortion. So much for the alleged excessive low-level distortion from digital program sources.
The intermodulation distortion (using mixed signals of 60 and 7,000 Hz in a 4:1 ratio) was 0.007 per cent at 0 dB. The 1,000 -Hz channel separation was a very good 99 dB, and it was 96 dB at 20,000 Hz. The flutter was at most the residual of our test equipment, somewhat less than 0.002 per cent.
The Marantz CD73 traverses a disc rather slowly; it took 11.5 seconds to slew from Track 1 to Track 15 of the Philips TS3 disc. But it had superior resistance to external shock and to disc defects. It took firm blows on the player's top or side to jar the laser pickup from its correct position relative to the disc, earning it an "A" rating in this respect. The Marantz CD73 also had no difficulty playing every part of the Philips TS4A test disc, whose progressively greater built-in surface defects eventually cause dropouts or even worse audible effects with most other CD players.