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Product Review - Yamaha DVD-S700 DVD Player with DTS Digital Out - July, 1998

John E. Johnson, Jr.

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Yamaha DVD-S700 DVD PLayer

Plays DD, DTS, and 24 Bit/96 kHz Discs

Coaxial and Optical Digital Outputs, 6-Channel Analog DD Outputs (DD Decoding Built-In), Stereo Analog Outputs, 2 Coaxial Composite Video Outputs, 1 S-Video Output, Coaxial Component Video Outputs

10 Bit Video D/A

Size: 3 1/2"H x 17"W x 11"D

Weight: 8 Pounds

MSRP: $799

 

Yamaha Electronics Corporation, USA, 6660 Orangethorpe Avenue, Buena Park, California 90620-1345; Phone 714-522-9105; Web http://www.yamaha.com.

Well, we have had DVD for more than a year now, and it is showing signs of success in the marketplace. Most of the people who have bought players appear to have laserdisc players already, and the LD market penetration is about 2 million players in the US. Manufacturers, and, of course, the movie studios, hope that the mass market will eventually buy into DVD big time, like VCRs. The lack of recording ability with DVD is an obstacle to selling DVD players, but really, we don't have to give up our VCRs just because we buy DVD. I still have my VCR and use it for all the things I used to, except for playing rental movies. DVD image and sound quality are obviously better than VCR tapes, but much of the public does not seem to care. Perhaps after HDTV takes hold, and everyone sees how good the TV picture and sound can be, the general public will jump into the DVD arena.

The Yamaha DVD-S700 is a second generation DVD player, and they have obviously learned a great deal from the first generation. The video D/A is now 10 bit instead of 8, allowing for more video dynamic range, and more shades of gray (luminance). It has a set of 6 coaxial DD analog outputs (DD decoding is built-into the S700, actually, it is built-into all DVD players, but some, such as the S700 have the output jacks for the decoded DD 5.1 analog sound) for those users who don't have a DD decoder in their receivers (you would need a set of 5.1 analog audio input jacks on the receiver), but coaxial and optical digital outputs are also there for use with DD-capable receivers. DTS digital out is a new feature on the S700, now that DTS has finally settled on the method of flagging the DTS signals in DVD. Besides two coaxial jacks for composite video out, there is an S-Video jack, and a set of coaxial component video output jacks. This player has everything.

The Yamaha DVD-S700 Remote Controlremote control handles most of the features on the S700. Buttons are there for power, open/close, play, stop, pause, skip (chapters), search (within chapters, at numerous speeds), on-screen menu, subtitle on/off, angle, and setup. In order to activate the digital output from DTS DVDs, you have to use the setup function, choose menu item 7, go to number 3 (DTS), and turn it on. The factory preset position is off, so it has to be turned on before playing the disc. Otherwise, the DTS DVD will play only the video and not the audio. While you are at it, you can turn on the LPCM, which will give you 48 kHz/16 bit digital out from 96 kHz/24 bit Digital Audio Discs (DADs). It is not possible to get a 96/24 bitstream from the digital output due to copyright restrictions that are in effect. Fortunately, the S700 has a 96/24 DAC built-in, so you can use the stereo coaxial analog output jacks to hear 96/24 DADs as they are meant to be heard. It is also a nice way to compare 96/24 with 48/16, although the latter is created by downconverting the 96/24 (not really a fair way to make the comparison).

Speaking of comparisons, I played some conventional CDs (44.1 kHz - 16 bit) on the S700. Like other DVD players, the S700 does only a marginal job of playing CDs. The reason for this is that the laser is really designed to play the narrow track of DVDs, not the wider track of CDs. The CD sound was very harsh, and not even as good as an LD player (also notorious for mediocre CD performance). However, when I played a 96/24 DAD ("The Super Audio Collection and Test Disc", DVD-171 Chesky), the front panel of the S700 displayed "96/24, and the sound was a much different story (it sounded great!) There has been a great deal of controversy about whether increased sampling results in improved sound. Some say it does and others say it is marginal, if at all. Blind testing will eventually solve this issue. Theoretically, you only need two samples for the highest frequency sampled (20 kHz), so 44.1 kHz should be enough. But that is only the theory, and Nyquist's Theorem, upon which the 44.1 is based, is derived from Nyquist's original work published many decades ago, before the age of digital electronics. Practically speaking, the process is far from perfect, and the analog filters at the end of the DAC cause phase shift regardless of whether they have a shallow or steep slope, plus, the filters are electronic circuits in the signal path. The bottom line is that 96/24 on DAD sounds very, very good. Maybe the DAC does not have to work as hard at recreating the original waveform, but whatever the reason, the sound from the modest DAC in the S700 does just fine. Full bodied sound, with minimal harshness. It will be interesting to see if there is as much difference between mass market 96/24 DACs, such as in the S700, and high performance 96/24 DACs, as there is between mass market 44.1 - 16 and high performance 44.1 - 16.

The image quality from the S700 is marvelous. Of course, the image from first generation players was great too, but the addition of a 10 bit video DAC allows more quality in the color rendition. I don't have access to a component video TV yet, but the picture from the S-Video is breathtaking by itself. I received the latest DTS DVD demo disc from DTS, which is the final format, and was just released the week of July 20, 1998. It has scenes from upcoming DTS DVD movie releases, such as "Apollo 13", "Daylight", "The Relic", and Dragonheart". The trailer from "Titanic" is also there. We took a screen shot [copyright respective studios] using the DVD-S700 and the DTS DVD, shown below. The photo is unmodified, that is, no adjustment of color, sharpness, brightness, or contrast from the jpg file as stored in the camera. The pale blue and pink horizontal stripes on her hat are moire patterns from our interlaced digital camera trying to capture the interlaced image from our direct view TV. Scene from TitanicThe picture as it appears on the TV is actually much more beautiful than the photographed image shown here. Even so, the jpg here on the web page is striking for having been taken from a television don't you think? Does this mean that the "Titanic" DVD will be in DTS? "No comment," was the response from DTS. DTS DVDs have very little video compression, meaning that the bit rate is high. I did not see any problems with this disc or the "Video Essentials DVD", which also has a high bit rate, playing them on the DVD-S700. In any case, the DTS audio bitstream is output at 1.536 megabits per second (1,536 kilobits per second), compared to 384 kilobits per second from Dolby Digital. The basic rate is 192 kilobits per second, and DD as well as DTS are multiples of this frequency. So, DTS has 4 times the bit rate of DD. Does that mean DTS sounds better? To my ear, the DTS DVD sound had a little more body to it, but the same amount of harshness (which is not very much) as DD DVD movies. However, we would really need an A/B comparison of the same 5.1 sound track, coded for both DD and DTS, on DVD. The level balance would have to be exactly the same. That sort of comparison is not available right now, and if it were, it would make no difference, because it is not a contest. By mid-1999, most receivers will have DD and DTS decoding built-in, and consumers will just plunk the DVD into their players and watch the movie, probably not paying much attention to the format that it has. There is one interesting note in the S700 instruction manual that says, "Some DTS decoders which do not support DVD-DTS interface may not work properly with the DVD/VIDEO/ CD/CD player". I think this may just be a disclaimer in case one or more of the older DTS decoders has a glitch with the DTS bitstream out of the DVD-S700. Hopefully, this will be rare.

I also played some DTS CDs, as well as a DD DVD audio only disc ("DVD Music Breakthrough", Delos DV 7002). As you may know, DTS 5.1 music is available on numerous CDs right now, and they will play on any CD player with a digital output jack. All you need to do is connect the digital out from the CD player to the digital input on a DTS decoder. For DD, music-only is available on DVDs, so you need a DVD player to play them. In any case, 5.1 music is terrific. I am looking forward to testing the jitter reduction components that are becoming available for use with 5.1 bitstreams, regardless of whether they come from a CD or DVD. When I took the 44.1 - 16 digital out from a standard CD, and let the Yamaha DSP-A1 decode it, the sound was still harsh, indicating severe jitter from the S700 transport (as I said, all the mass market DVD players are like this, and it is not peculiar to the Yamaha). This was not so much the case when I used an LD player (Yamaha CDV-W901) as a transport, with the DSP-A1 decoding the 44.1 - 16 bitstream. I suspect that 5.1 will benefit from jitter reduction devices as much as conventional 2-channel stereo. Jitter reduction components are placed between the transport and the DAC.

The on-screen menu has selections for jumping to specific tracks, jumping to specific chapters, jumping to specific elapsed time, changing the spoken language (not available on DTS DVDs since DTS uses an audio bit rate too high for this, and making room for several different languages is one of the reasons Dolby chose a lower bit rate for DD audio), displaying the sampling frequency (96, 48, 44.1), displaying the bit rate (24, 20, 16), changing the subtitle language, changing angle of view when available, and audio mode. This menu is displayed across the top of the screen. The setup menu, on the other hand, is displayed item by item in vertical fashion. There are selections for language, ratings (playback of violent or X-rated movies can be locked out), menu language (English, French, and Spanish are immediately available, while dozens of other languages, such as Cambodian and Sudanese, can be set by entering a 4 digit code number), on-screen message display (such as play and stop) can be turned on or off, brightness of the player fluorescent display panel, aspect ratio (for when you have a 16:9 TV), digital audio output (turning on or off the LPCM, DD, or DTS digital out), speaker settings for the various channels (large, small, none, delay, loudness, and test signals) when using the built-in DD decoder, and audio dynamic compression. You can even decide whether you want or don't want sound when using the double speed search feature. Like I said, this player has everything.

Because DVD is still new, we are likely to see most of the improvements between the early generations. The second generation Yamaha DVD-S700 has added 10 bit video D/A, DTS capability, 96/24 capability, built-in DD decoding, dozens of languages for on-screen menus, and lots of other features. It is well built, handles smoothly, and is a pleasure to use.

John E. Johnson, Jr.


© Copyright 1998 Secrets of Home Theater & High Fidelity
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