what sounds better than a Momitsu V880N?

[NaTT]

pretty much everything right?
but how do I get the functionality of this player (networking, plays DivX, HD scaled output etc) and it's DVI output and get good quality sound?

By good "quality sound" I mean >= a Pioneer DV-717, hooked up to a Yamaha A2 and B&W 602s where I'd be replacing the DV-717.

I'd be feeding a Pioneer 43MXE-1s which isn't HDCP enabled.

Given that it's digital out, the sound should be OK, unless there's jitter which there probably isn't much and/or the A2 will reclock it. Just don't use the analogue output of the 880N.

What I don't know is if the HDCP can be disabled like on the 880.

[NaTT]

cool, like the idea of that but my x-box has a digital out and lacks the clarity in a back to back test against my DVD player, so I've come to believe that not all digital signals give the same performance?

I'd say your back-to-back test has some other difference; the two sources aren't sending the same raw disk audio data from the same disk going into the Amp set the same way. Try playing an audio CD, and disabling the reprocessing the 717 does (legato & hi bit?), and making sure the A2 is set for direct A/D conversion without reprocessing. I expect the A2 can help out the Momitsu & Xbox with the same sort of upsampling that the DVD player does if that's what's making the difference.

[NaTT]

hmm

I've done a couple of back to back tests, one with a PC and the other with my xbox. Both resulted in noticable additional "layers" or clarity from the DVD player.
The tests:
I set the amp to take straight PCM, and played 2 Gygpsy Kings - Gygpsy Kings CDs at the same time (Only difference was one input was optical and the other coax)
So I was able to toggle between the 2 digital and played with sources.

I'm fairly sure anyone would get better audio and picture play back from say an Arcam of some sort (over a Momitsu), but are there any "high end" players that have these network, divx and DVI/HDMI features?

[stevelup]

Hi

If you are primarily interested in watching movies, then there will be absolutely no difference whatsoever between a £29 supermarket DVD player and a £1000 Arcam when it comes to audio.

All the decoding is taking place inside your amplifier - all that is being transmitted from your DVD is the raw stream.

Doing the tests with Audio CD's is not a valid test in these circumstances.

This is because PCM data is prone to jitter whereas the digital bitstreams are not. You also used two different interfaces - optical and coaxial. For DD / DTS this doesn't matter one iota, but for PCM the electrical interface can impact on jitter. The Electical>Optical>Optical>Electrical conversion is the culprit here.

Steve

[NaTT]

ah ha thanks. I think I've just spotted a big flaw in my presumed knowledge.
Could you elaborate on the differences between PCM and digital bitstreams?

Assuming then that I will also use the player to play CDs, should I then be considering keeping the old DVD player (if turns out that the Pio is better for audio) or getting a dedicated CD player? (given that I'll probably carry on connecting CDs to my amp via a digital connection).

[stevelup]

With a PCM signal, both the value of the bits (0 / 1) *and* the timing with which they arrive combine to determine the ultimate signal.

Because the digital signal is inherently analogue (in the sense that it is a change in voltage), there is the potential to introduce timing errors.

If the driver (in your CD player) or the receiver (in the amplifier) are mismatched, it is possible for the receiver to capture the sample of that particular bit at the wrong time. This is known as jitter and can blur the resulting sound.

With DD and DTS bitstreams, the data is sent in packets which are only decoded when they have been received in full.

Therefore, PCM sound can be affected in a more "analogue" way by dodgy cables or converters. DD or DTS will simply drop out altogether.

I don't think it will make a great deal of difference which player you use if you are going to use the digital inputs.

My recommendation would be to buy a good second hand CD player (NAD or Arcam) and connect it up analogue!

Steve

[John Dawson]

Steve1up - what you are talking about is gross misreading of the data, not jitter.

However, it is simply incorrect to say that because DD or DTS data is transmitted in packets that it always sounds identical after decoding when transmitted down an SPDIF cable. Briefly, the reason is as follows:-

In both PCM and any other type of digital transmission over the SPDIF interface, the master clock signal is contained as part of the overall SPDIF signal and has to be reconstructed downstream. It is this derived master clock signal that is used to reclock out buffered data and drive the receiver's DACs and so it is susceptible to jitter in the transmitted SPDIF signal, as the industry standard PLLs used to pull out the clock are not particularly good at filtering out jitter. There are ways round this but they are rarely implemented in commercial AV receivers as they are quite expensive.

In my experience you will usually be able to hear differences between properly implemented and badly implemented DVD players, when using their digital outputs into commercial AV receivers, and it will not pay to skimp here if audio quality matters to you.

John Dawson (Arcam)

[stevelup]

Hi

Do you not agree with the following (which was more my point):-

1) With PCM data, subtle errors can be introduced into the signal path which will - without producing noticible dropouts - change the character of the played back sound.

2) With DD or DTS bitstreams, these errors will result in noticible dropouts.

AC3 and DTS both all have CRC checking - it is simply impossible for them to be contaminated during their journey from DVD player to Decoder.

They will either work, or not.

Steve

[sticker]

OK if all Dolby digital and DTS (through electrical coax or optical) sound the same regardless of the DVD player being a £30 or a £1000 one. Then can someone explain to in a detailed explaination the steps from the DVD being at a static position in the DVD player tray through to the signal entering the Coax/optical lead?

I'm a sceptic that all 1's & 0's are the same as I would have thought that the process from start to finish is fraught with variables that can influence the outcome.

Regards
John

[stevelup]

Error correction is the answer. All DVD's have extensive error correction.

The bytes of data are arranged (for error correction purposes) into a grid of 192 x 172 columns. To each column, 26 bytes of recovery data is added.

In each block, it is possible to recover at least 5 byte errors per row, and 8 byte errors per column.

This is incredibly robust.

Add to this the fact that the DD / DTS packets also have a checksum. Once the data reaches your amp, if the checksum for that particular packet is not valid, the packet is dropped. This results in audible dropouts.

There really is no inbetween - it either works or doesn't.

Steve

[NaTT]

so there's a chance that even though the V880 is a great all rounder and can't fail me too much on DVD sound tracks, when I'm in an audio file mood and playing CDs (via digital link because I "think" it's a better link) I may need to have a seperate box for this as there isn't a "high-end" manufacturer farting around in this convergence space?

[stevelup]

There are some DVD players which are very good at CD playback - no doubt about it.

I'm of the opinion though that if you really care about your Audio CD playback, it would be more cost effective to pick up a used quality CD player.

Steve