kinmonth@null.DEC (Bruce Kinmonth 225-5019) (06/21/85)
This past weekend I had the opportunity to try out two CD players at home. The players were the Denon 1800R ($950) and the Nakamichi OMS-7 ($1295). They were loaned to me by The Natural Sound, Route 9 in Framingham, MA. One reason that I chose to compare these two was their different filtering methods. The Nak uses quadruple oversampling and a seperate D/A converter for each channel. The Denon uses the 44.1 K sampling rate with analog filters, and (I think) one D/A converter multiplexed between the two channels. I've read argument after argument about filtering techniques and phase distortion, etc., and I wanted to see for myself if the difference was audible. After careful listening to several types of music, I had to conclude that I could hear no difference between the sound of the two players. The only time I though (imagined?) I could here a difference was with solo type string passages, such as string quartet music. I thought the Nak might have a slightly smoother sound there, but don't take this too seriously. I also feel that if I didn't know ahead of time which player was playing, I would be unable to tell the difference with any statistically meaningful accuracy, even in these string passages. The features of both players were similar. Both come with remote control. Both have a 10 digit keypad for direct access of any track. Programming features were about the same. I didn't have the manual for the Nak, so I had to figure it out myself. Each could program tracks in any order. The Denon lets you program up to 15 selections. I don't know about the Nak. Each allowed a track to appear more than once in a program sequence, something other players often do not allow. Each has the usual skip f, skip b, ff, and frev buttons. I liked the Nak much more with the ff and frev functions. The Denon chopped the music up too much. In fast forward, you heard about four pulses of sound per second. The gaps between the pulses were the same length as the pulses, i.e. 1/8 second sound, 1/8 second silence, etc. The Nak, on the other hand, was much smoother, having much shorter silent sections and a much faster pulse rate (maybe 20 times a second or so). The Nak also played FF and FR at about 5x speed for around 5 seconds, and then would kick into a faster speed, say 10x. Putting either player in PAUSE and then using FF or FR caused a much faster but inaudible scan, somthing like 30x. Again, the Nak had a 2-speed feature in this mode. One bad thing about the Nak fast forward and fast reverse functions (and this really surprised me, I had to try it several times before believing that it really happened) is that hitting either of these functions while a programmed sequence is playing erases the sequence! That's right, you can't fast forward, even within a track, without clearing out any programmed sequence. The Denon did what I expected: fast forward worked fine; if I ff'ed past the end of a track, it went on to the next track in the programmed sequence. If I FR'ed past the beginning of a track, it went into the previous track in the program. Both players have the REPEAT function, which repeats the disk, or repeats the program if present. The Denon has a button marked INTRO. It causes the player to play the first 10 seconds of each track. The Denon also has an A-B repeat function that lets you automatically repeat any section (or skip any section if A>B timewise). The Nak has neither of these functions. The Nak has a button marked INDEX which lets you use the keypad buttons to directly access even the index points. For example, you could go directly to track 4 index 7 by hitting "4" "INDEX" "7" "PLAY". The Denon lets you go directly to a track, but to move to a given index point within a track you have to go to the start of the track and then step seqentially though index points to the one you wanted. The "go to next index" function is done by pressing the PLAY and FSKIP buttons together. Similarily you can go to the previous index point with PLAY and RSKIP. This direct access to indexes with the Nak made me wonder if you could program index points as well as tracks, so I tried it. Sure enough, the Nak would accept track and index into the program. There was one major flaw in their software though (at least in my opinion). Although part of a program could say "start at track X index Y", when that index played, the player would then play to the end of that TRACK, not to the end of that INDEX. So, if you told it to play track 4 index 5, then track 2, and finally track 4 index 8, the Nak would start at track 4 index 5, play all the way to the end of track 4, then play track 2, and then play from track 4 index 8 all the way to the end of track 4 again. What I really wanted it to do was play 4 index 5, then go from the end of index 5 to track 2, then to 4 index 8, and at the end of index 8, stop. Apparently the logic only looks to see what's next in the programmed sequence at the end of a track, not at the end of an index. Both players had a CALL button. On the Denon, CALL would show the total disc time and total number of tracks when the player was STOPed and no program was stored. If a program was stored, it would show the program. If no program was stored and the player was not STOPed, the CALL button did nothing. The CALL button on the Nak only showed the programmed sequence. If nothing was programmed, CALL did nothing. The Nak had another button called REMAINING. Pushing it at any time displayed the number of tracks remaining to be played (count included the currently playing track which felt a little odd...) and the total disc time remaining. However, the REMAINING button did not do anything if there was a sequence programmed (i.e. the Nak could not add up the time or figure out how many tracks remained in a program). The Denon was able to add up programed times to a point. Pressing the CALL button with a program not only displayed the program sequence, but displayed accumulated time as it added up the playing times of the individual tracks. The drawer of the Denon opened and closed noticably faster than the Nak. The motor mechanism for the drawer was noisier on the Nak. Although the Nak was noisier opening and closing its drawer, it was quieter during playback than the Denon. With the speakers off, I could not hear that the Nak was in play mode from about 5 feet away. The Denon was definitly noisier, and produced a faint ticking sound. From 5 feet the Denon was clearly audible. Neither player was noisy enough to intrude upon normal listening levels. Both players were very fast seeking for a given track. The Nak was equally as fast seeking a given index. The Denon, which only steps sequentially though index points, was surprisingly slow at finding the next index. It clearly was scanning through the disk data looking, because the longer the distance (timewise) to the next index, the longer it took to get there. I put the Denon at the beginning of a fairly long track that had no index points, and told it to go to the next index. It took quite a while (maybe 10 seconds or so) before arriving at the next track. One thing I missed in both players was the ability say something like "play all tracks except #5". The only way to do that on either player was to program 1,2,3,4,6,7.... It seems to me much more likely that a person would want to omit a given track or two than program very long sequences in oddball orders. The display on the Denon was a bit more informative than the Nak, especially with respect to programming. The Nak basically showed only track number and track elapsed time. It also showed if REPEAT was on, and if a disc was in. The Denon showed the track number, the current index number, the elasped time, and the next track to play in the program. It also showed states of various modes like A-B repeat, REPEAT, INTRO, PROGRAM CALL, etc. All in all, both players made my system sould better than I have ever heard it. I'm not sure where I see that the Nak is worth $350 more. It has direct access to an index, and remaining time at any point. I don't count the ability to program an index into a sequence because it doesn't do what you want. On the other hand, the Nak doesn't have A-B repeat or the INTRO function. I don't really see much use for the INTRO function, but A-B repeat might be useful. Also, the fact that the Nak zaps any sequence you've programed if you hit FF or FR really bothers me.
copp@petrus.UUCP (06/26/85)
Thank you--for a frank and useful review!