3 year old Denon DVD-A1 v 3930. My verdict..

Thanks for that review, very helpful! :smashin:

I am going to demo one tomorrow as a possible replacement for my Pioneer 868. I was hoping that the audio would be a great improvement over the Pioneer, but you have given me food for thought.

Off to buy Recruit's DVD A1XVA today - it was always on my mind that it may have been more cost effective to just buy a 3930. Although you havn't done a direct comparison between those two players - it kind of put's my mind at rest, that I have done the right thing. :)

From what I can tell from a couple of reports here it definitely sounds like the picture is excellent, but the audio is average. It's such a pity Denon can't get it together. For ?00 you should get something which you can actually use as a universal player. I'm sure for many it will be fine, but for others who expect more it sounds like it may be frustrating. I dare say the money has gone on the video processing rather than the audio!

Nice well balanced review thank you.

Have you tried the 3930 via component and if so how does it compare to the A1?

An excellent review and one that matches my own views on the product.

If audio quality is of importance then the new Arcam DV139 might be worth a spin, it knocks both the 3930 and the A1XVA into a cocked hat for audio performance.

Out of 10, I'd mark them as follows for their component ouput.

A1 (Progressive) = 9.5
3930 (Progressive) = 9

A1 (interlaced) = 9
3930 (Interlaced) = 7

The 3930 gets a low score for interlaced output because it is riddled with the Chroma Bug in interlaced mode.
It can look a little out of focus aswell. This is a shame because you are limited to interlaced component ouput if HDMI is switched on. It takes a few button presses to switch HDMI On/Off, so I doubt family members will know what to do when they find no signal going to the projector)


I did mention above that the A1 has absolutely no noise in the picture and looks a bit 'cleaner' than the 3930's progressive output. The 3930's progressive component output is still very good though.

An excellent review and one that matches my own views on the product.

If audio quality is of importance then the new Arcam DV139 might be worth a spin, it knocks both the 3930 and the A1XVA into a cocked hat for audio performance.

But is not so good as the A1XV when it comes to video, which is why exactly one buys a dvd player. (personal preference noted)


Jules
Also you say even via denon link the 3930 sounded not as good as the A1, are you saying the A1 has better dacs than the amp you have. I had the A1 and i dont think it rates as an audio player, certainly not bad but nowhere up to the spec of a decent av amp with quality dacs.

but for £899 the 3930 is one of the recent bang for buck bargains at its price point, i forget how much an A1 was but it wasnt too cheap when i bought one.

Have demoed just about every arcam, and yet to buy one. (audio is always impressive, video always lacking but the most perfect VP fodder, bar the 27a which i almost purchased @ the time they were a hot product, and regret not gettin one)

"but it switches to Interlaced when using HDMI (I didn't know this)."

I take it you did change it in the menus to progressive, and tested it in each of its modes.

I should say i demoed the 3930, along with the Denon A1xva amp, you know the friggin great monster, (which you can now find for about £3k) and via Denon link 3 the audio quality was excellent, though the amp was doing the grunt.

"but for £850 the 3930 is one of the recent bang for buck bargains at its price point, i forget how much an A1 was but it wasnt too cheap when i bought one.

Have demoed just about every arcam, and yet to buy one. (audio is always impressive, video always lacking bar the 27a which i almost purchased @ the time they were a hot product, and regret not gettin one)[/QUOTE]"

It is £1100, where have you seen one for that? (Purely Gadgets have grey imports at £879.)

I take it you did change it in the menus to progressive, and tested it in each of its modes.
Yes, and then I read the manual... which told me what I had suspected.

Also you say even via denon link the 3930 sounded not as good as the A1, are you saying the A1 has better dacs than the amp you have. I had the A1 and i dont think it rates as an audio player, certainly not bad but nowhere up to the spec of a decent av amp.
My amplifier is a Denon (K)A1SE. The DVD-A1's DACS are better than those in the amplifier, but using Denon Link (and therefore using the DACS in the amp) is more convenient.
I don't therefore think the quality of the DACS in the DVD player are relevant in your question. I can only presume the difference between the 3930 and A1 in this scenario is due to the DVD-A1's vastly superior transport and build quality.

I actually rate the A1 very highly as a CD player. When I first got it, I was really taken aback by how it good it was.

"but for £850 the 3930 is one of the recent bang for buck bargains at its price point, i forget how much an A1 was but it wasnt too cheap when i bought one.

Have demoed just about every arcam, and yet to buy one. (audio is always impressive, video always lacking bar the 27a which i almost purchased @ the time they were a hot product, and regret not gettin one)"

It is £1100, where have you seen one for that? (Purely Gadgets have grey imports at £879.)[/QUOTE]


AVland my friend, UK stock, Denon gold dealer, GooGle is your friend if you want to get good deals

Edit, make that £899 MR
http://www.avland.co.uk/denon/dvd3930/dvd3930.htm

With the endless wait for HD DVD and Blue Ray, and with the HDMI socket looking lonely on my Sony HS50 projector, I decided to replace my 'no HDMI' Denon DVD-A1 for a brand spanking new Denon 3930.

The other reasons for my decision were:

- I could get the 3930 in black to match almost all of my kit (everything is going black again!)
- using HDMI frees up the component ouput to my Plasma. Previously I had to use S-Video on the A1.
- The 3930 plays SACD where the A1 does not.


The 3930 has had lots of high praise thrown at it for its upscaling abilities over HDMI, but is it really like Denon's A1 players for 1/3rd of the price?

Well, over HDMI and using 720p upscaling to my HS50 the picture is beautiful.
Yes, better than the component ouput from my DVD-A1, and so I'm very happy with it.
The 3930 is a belting DVD player , and the upscaled picture from most films looks alot better than component. Infact I'm very impressed.

However, before you jump up and buy one... there are a couple of very big
caveats.

1) Audio quality.
The audio quality is pants compared to the A1.
With CD's, the A1 sounded better than my NAD C542 CD player... which in itself is a very fine CD player.
The 3930 sounded considerably worse than the NAD. The results were obvious... the 3930 is not even close the performance of the A1 with CD.

I thought that using Denon link, the 3930 and A1 would sound the same.
I was wrong! The 3930 sounds good over Denon Link, but switching to the A1 made CD's sound more wholesome, rich, smooth, controlled and detailed.
Even Dolby Digital via the A1 sounds better...not quite so much in it, but definately more refined.


2) The component video output from the 3930 is very good, but it switches to Interlaced when using HDMI (I didn't know this).
Also, when I switched back to the A1 for a moment, I noticed the complete absence of any noise in the picture. The 3930 looked less pristine.
The A1 perhaps looked a little soft, but I couldn't say there was less detail in the picture.... it just looked a bit 'cleaner'.


3) The drive speed. I hadn't appreciated how slick the A1 was.
The A1 whisks through DVD menu's like greased lighting. The 3930, whilst not slow (much quicker than my Panasonic DVD-R) was no match for the A1.


4) Build quality. People say how well made the 3930 is, and it is a very nicely put together machine. But again it is no A1. The top and side panels flex when you pick it up.
I wouldn't (and didn't) put the A1 on top of the 3930, but I have put my 28Kg Amplifier (Denon A1SE) on top of the A1.
The 3930 feels like it will last a fair few years, whereas the A1 feels like it will last a lifetime.


Overall, I'm very happy with the 3930 because if feeds my HS50 a better picture using HDMI and I can use the component ouput to feed my Plasma instead of S-Video.
As a DVD player, especially over HDMI, I rate it very highly.

However, if I didn't have a NAD C542 CD player to play music on it would be a different story.

The 3930 is a stonking DVD player, but if you want a one box CD / DVD solution, my advice is to look elsewhere.

what about denon dvd a11 for cd replay?

Yes, and then I read the manual... which told me what I had suspected.

My amplifier is a Denon (K)A1SE. The DVD-A1's DACS are better than those in the amplifier, but using Denon Link (and therefore using the DACS in the amp) is more convenient.
I don't therefore think the quality of the DACS in the DVD player are relevant in your question. I can only presume the difference between the 3930 and A1 in this scenario is due to the DVD-A1's vastly superior transport and build quality.

I actually rate the A1 very highly as a CD player. When I first got it, I was really taken aback by how it good it was.


Well we must just a have different view of what makes for good audio, but i i doubt there is a difference via D-LINK between players, that would be a first. as long as the d-link is sending the same digital signal, its all down to the dacs off the amp, therefore this is simply placebo effect.

If you were talking about the analog outs, then i can understand the difference, not trying to snipe. (did you also try the anolog outs of the 3930 for audio)


from the audio holics review of the 3930.

Starting off with some 12-string harmonics the title track, “Carry On Together? only gets better by adding tight harmonies into the intro verse. Tracks like this are exceptionally revealing and the DVD-3930CI was extremely transparent sounding. The DACs on this player are simply astonishingly good."

full review here

http://www.audioholics.com/productreviews/avhardware/denon-DVD-3930CI-DVD-playerp1.php

I think the 3930 is just a bit too bright and digital sounding.... something I hate in digital audio and the DVD-A1 avoids this.

I guess I do subscribe to the idea that digital conenctions can and do sound different.
I genuinely firmly believe this is not placebo. After all, I don't think anyone would argue that the coaxial digital audio output from a ?0 player from Asda sounds the same as that from an Arcam.



A quick update on the component video ouput from the 3930.
I'm going to have to knock it's score down to 7/10 for interlaced ouput.
It is riddled with CUE.
I've just been watching a brightly coloured Pop music video, and the interlaced component picture is poor. Not a patch on the A1.

Weird thing is that the progressive ouput is much better.
It's just a shame I have to switch HDMI off to maintain progressive component ouput to the plasma screen... and there's no discrete IR command I can programme into my Pronto to acheive this easily.

indeed there is cue in the interlaced mode, kris dearings pointed that out, though if one were to use this player in interlased mode they should be shot onsight. (what with HQV and all), I dont know this for sure but perhaps the progressive mode has CUE filters, a good check could be to look at starwars the clone was where bobba fets dad (jango)is shooting at obi wan in the space scene (seizmic charges says obi wan), the instrument panel has a few bright red dials etc, do these go all banded in interlaced mode and progressive or just interlaced? (thats if you have the time to look)

What you mean those asda Players arent just bulk rebadged arcams, ive been stung.:)

Though we arent talking about a £20 dvdplayer, I found the Audio from the 3930 to be excellent, redbook CD was most impressive, very detailed with excellent clarity. SACD had great dynamics and sound steering. As good as an arcam for redbook cd, no. but i also own a NAD C542 and the Denon in my opinon produced a finer sound, but not even a contender for my dedicated NAD silverline system or now departed A1XV

Hi all,


Off topic question?

Would it be possible to use a hdmi-dvi adaptor from the denon 3930 to a 42phd8 to achieve 1:1 pixel mapping [1024x768p] to bypass the screen's scaler as my screen does not accept 1:1 mapping via hdmi. obviously I may not be able to use this "colour expansion function" in the hdmi setting for dvi.

any advice would be appreciated.

The 3930 has 1080p output over HDMI - but you are using component??

You also mentioned that you had been watching your previous DVD player over S-Video?

A quick update.

I'm not as enthusiastic of the 3930 as I was at first, and slightly regret agreeing to sell my DVD-A1.

First, the multi region hack is not perfect. It won't play my Region 1 copy of Daylight with enhanced regional coding. the DVD-A1 played it fine.

Secondly, the component video output is definately inferior to the A1, and horizontal pans are not as smooth.

Thirdly, probably being too picky here, but the drive speed is too slow for me.
I was used to navigating menus on the DVD-A1 in double quick time, and the 3930 is starting to iritate me as it thinks for a few seconds before responding.


Also, not the 3930's fault, but my Sony projector (HS50) crops the image using 720p upscaling and leaves an unused border inside the 16:9 frame.
I'm still connecting via HDMI, but have decided to use 480/576p instead of the 720p upscaling.
That means I'm not really gaining much when compared to the A1.

Oh well... you live and learn.

Very interesting thread, and proves what a lot of the old sages have been saying around these parts.

Quality is quality.

Denon link is one of the best digital audio connections, but it won't make anything better - it will just help to stop things getting worse, and in this case it will expose the limitations in the amp. People often assume that amplifier DACs are better than player DACs, but the DVD A1 was pretty much cost-no-object in it's time, and more bits haven't made anything any better in the meantime.

Nick

1) Audio quality.
The audio quality is pants compared to the A1.
With CD's, the A1 sounded better than my NAD C542 CD player... which in itself is a very fine CD player.
The 3930 sounded considerably worse than the NAD. The results were obvious... the 3930 is not even close the performance of the A1 with CD.


Excellent review Jules on many factes, one thing though dude, I am sure your C542 sound excellent, but what I hear from my DVD (Toshiba SD9500 & Sony NS900V QS SACD/DVD ) players knocks what I hear from ?00-500 CDPs into the weeds these days in hifi dealers. I think these old estoric players can "play ball" with many ?000 CDPs. Once you send these DVD player into dedicated stereo systems, it amazes me what they can produce audio wise. I'd reccomend geeing up your stereo system as high as you can go dude and keeping an old superstar DVD player like your A1 for CD duties.

A quick update.

I'm not as enthusiastic of the 3930 as I was at first, and slightly regret agreeing to sell my DVD-A1.

First, the multi region hack is not perfect. It won't play my Region 1 copy of Daylight with enhanced regional coding. the DVD-A1 played it fine.

Secondly, the component video output is definately inferior to the A1, and horizontal pans are not as smooth.

Thirdly, probably being too picky here, but the drive speed is too slow for me.
I was used to navigating menus on the DVD-A1 in double quick time, and the 3930 is starting to iritate me as it thinks for a few seconds before responding.


Also, not the 3930's fault, but my Sony projector (HS50) crops the image using 720p upscaling and leaves an unused border inside the 16:9 frame.
I'm still connecting via HDMI, but have decided to use 480/576p instead of the 720p upscaling.
That means I'm not really gaining much when compared to the A1.

Oh well... you live and learn.

OH Hangon, which is it then, on AVS you say you compared your A1 to the A1XV and the A1 is still just as good, here you say its the 3930.

Having owned the A1, A11, 2900, 3910, A1XV i call majour BS at this even more so with the thread you made on AVS. The A1 was pretty good, there was no doubt but the A1XV stomps on it in every way, its not even close.
So did you compare with the A1XV or the 3930?

(if it wasnt you you got a twin:) )

HCC is reviewing this model in their next issue.:thumbsup:

I am interested in this model to go with my AVC-A11XVA. My present dvd player is the oldish but (at the time) well respected semi budget model Toshiba SD-210e. It's still working fine but technology has, as is always the case, jumped forwards in leaps and bounds since this model was released.

Thanks for your real world owners review Jules as it gives food for thought.:smashin:

Denon link is one of the best digital audio connections, but it won't make anything better - it will just help to stop things getting worse,

Well said Nick. Some seem to think if it's denon-link to your amp it will sound the same whatever the Denon player. As you point out, not so.

Well said Nick. Some seem to think if it's denon-link to your amp it will sound the same whatever the Denon player. As you point out, not so.

How is it not so? just to clarify, because im yet to hear a difference after serious audition time, the sound just gets limited to the capability of the amps dacs, thus leveling the sound quality via Denon link, as to nicks point thats not always the best option as the player may actually have better quality dacs and your not using them.

How is it not so? just to clarify, because im yet to hear a difference after serious audition time, the sound just gets limited to the capability of the amps dacs, thus leveling the sound quality via Denon link,

Denon-link minimises jitter through the connection, it does not eradicate it, and therefore sound quality of the source player, re jitter, will still vary between players. Also, digital clocks vary between players. Some output 44.12khz, for example, whereas others might be running at 44.098 khz. Both these factors will effect the sound. When I feed my DV29 via spdif to my processor it sounds very different to my Sony 900V.

the player may actually have better quality dacs and your not using them.

I agree.

you honestly believe one can perceive the difference between 44.12khz, and
44.098khz., that is such a minimal spread its untrue. you would have to be in a complete sound proofed enclosure to hear such a difference

you honestly believe one can perceive the difference between 44.12khz, and
44.098khz., that is such a minimal spread its untrue. you would have to be in a complete sound proofed enclosure to hear such a difference

All I can say is that there are very real differences when outputting digital to a processor/av amp, and differences in clock rate & jitter are the only way I know of explaining it.

T.

jitter i fully understand but again the actual audible differnce requires a fair difference in the jitter to make for a perceived difference. That said combine all together and that would be an audible difference.

OH Hangon, which is it then, on AVS you say you compared your A1 to the A1XV and the A1 is still just as good, here you say its the 3930.
not me guv! I'm not a member of AVS. Must be someone with the same name, after all the world is full of people called Jules.

It's quite interesting the differences external clocks can make if you use a digital workstation. Clock it from one source and you find the bass isn't quite as pronounced, and another will make things sound 'chunkier'. Another might give greater stereo width etc, etc. I tried an external clock that was meant to have a very low jitter rate, but I found it made everything sound bland.

not me guv! I'm not a member of AVS. Must be someone with the same name, after all the world is full of people called Jules.

Oh OK...:smashin:

It's quite interesting the differences external clocks can make if you use a digital workstation. Clock it from one source and you find the bass isn't quite as pronounced, and another will make things sound 'chunkier'. Another might give greater stereo width etc, etc. I tried an external clock that was meant to have a very low jitter rate, but I found it made everything sound bland.

interesting indeed.

After all, I don't think anyone would argue that the coaxial digital audio output from a ?0 player from Asda sounds the same as that from an Arcam.

Actually, I would. Setting aside errored blocks either being transmitted or not (which would be converted into blips normally) bit are bit are bits. That's the point of digital. Using the SPDIF connection, whether optical or coaxial, on a ?0 DVD player vs a ?K Denon will produce identical bits. Sorry, this is simple fact.

I do however recognise that one may do "better" error correction (which should be rare with a clean disk and clean laser diode/lens) and also perform better - but the data delivered to the amp on the whole will be bit for bit identical.

I am somewhat ignoring the deficiencied of CDDA encoding and blocking etc.

Actually, I would. Setting aside errored blocks either being transmitted or not (which would be converted into blips normally) bit are bit are bits. That's the point of digital. Using the SPDIF connection, whether optical or coaxial, on a ?0 DVD player vs a ?K Denon will produce identical bits. Sorry, this is simple fact.

I do however recognise that one may do "better" error correction (which should be rare with a clean disk and clean laser diode/lens) and also perform better - but the data delivered to the amp on the whole will be bit for bit identical.

I am somewhat ignoring the deficiencied of CDDA encoding and blocking etc.

Its safe to say the difference is not as big as one would like, because use the internal dacs of the said Arcam player will then produce a much better sound quality again if the amps dacs are poo.

however power supplies, sheilding, etc etc will play there part.

Actually, I would. Setting aside errored blocks either being transmitted or not (which would be converted into blips normally) bit are bit are bits. That's the point of digital. Using the SPDIF connection, whether optical or coaxial, on a ?0 DVD player vs a ?K Denon will produce identical bits. Sorry, this is simple fact.

I do however recognise that one may do "better" error correction (which should be rare with a clean disk and clean laser diode/lens) and also perform better - but the data delivered to the amp on the whole will be bit for bit identical.

I am somewhat ignoring the deficiencied of CDDA encoding and blocking etc.


If you take a WAV file and copy it on a pc, and send it as an attachment, I grant you there will be no difference from that to the original, since it is literally copying data. But it doesn't work that way when a lazer is reading data from a spinning disc, which then sends the signal down wires to a DAC, and all this is subject to the players own clock. So you've got the transports stability having it's effect, the PSU, RF interference, and of course the digital interface if it's being sent to an external av amp/dac.

Actually, I would. Setting aside errored blocks either being transmitted or not (which would be converted into blips normally) bit are bit are bits. That's the point of digital. Using the SPDIF connection, whether optical or coaxial, on a £20 DVD player vs a £3K Denon will produce identical bits. Sorry, this is simple fact.I usually keep my tongue on a tight leash and watch what I say pretty carefully, but I'm quite convinced that is absolutely wrong.

If it was correct, why doesn't SPDIF sound the same as iLink or Denon Link? Why do I2S connections sound better? Why do clock upgrades improve sound, even where digital connections are made to DACs / amps? Why does an SPDIF re-clocker improve SQ?

Bit errors don't seem to be a significant problem, even with cheap players. Only where the disc is dirty or damaged. No, the real problem is simply jitter, and it's a significant problem, and a very audible one. The issue is that SPDIF doesn't just carry digital amplitude information - it also carries timing information. This defines the point in time where the sample is recreated back into an analogue signal. Getting the timing information right appears to be just as important as getting the amplitude information right.

This is why a Denon DVD A1 can sound better with an analogue connection to an AVC-A1SE than with a digital one. Whether it's audio or video, digital isn't intrinsically better than analogue; the problems and the solutions are just different.

Nick

This is why a Denon DVD A1 can sound better with an analogue connection to an AVC-A1SE than with a digital one. Whether it's audio or video, digital isn't intrinsically better than analogue; the problems and the solutions are just different.

Exactly and agreed. Digital signals are digital signals however, and jitter at that level is almost unmeasurable and certainly not by people's ears. Placebo effects are far better and more reasonable explanations. If not, I have homeopathic cures for cancer in the back of the car...

Merry Xmas all.

Digital signals are digital signals however, and jitter at that level is almost unmeasurable and certainly not by people's ears. Placebo effects are far better and more reasonable explanations.

Merry Xmas all.No, with respect I don't think we agree. If digital is digital, then my wife and very maany other wouldn't have noticed the difference between SPDIF and ILink without prompting. It's not about faith or snake oil; the difference is broad as daylight and I will happily demonstrate it to to anyone who cares to come round ..

Yes, Merry Xmas

Exactly and agreed. Digital signals are digital signals however, and jitter at that level is almost unmeasurable and certainly not by people's ears. Placebo effects are far better and more reasonable explanations. If not, I have homeopathic cures for cancer in the back of the car...

Merry Xmas all.

With all respect it doesn't sound like you have much experience of working with music & digital audio. Any knowledgeable producer/engineer, or music lover, knows the shortcomings of digital; and when it was first introduced discovered you couldn't just make digital copies of copies, because they didn't sound like the original. Jitter was increasing with each copy.

Why do people like Arcam make such an effort to reduce jitter in their audio equipment? Because they know it makes the utmost difference.

It is hardly snake oil. If you haven't been able to hear the difference then a quick demo of an spdif connection to a Denon-link one should easily prove to your ears the truth. Jitter can be measured, and is very audible.

Happy New Year :)

T.

and when it was first introduced discovered you couldn't just make digital copies of copies, because they didn't sound like the original. Jitter was increasing with each copy.

The point of using "digital" is to make sure that the information can be copied without loss. If you mean that the transmission of that information may be unreliable, then I agree. I cannot however let that statement go that copying digital data is lossy in anyway at all.

Jitter is introduced by timing issues. Perhaps Denon's proprietary system has a window size for raw data and regenerates clocks at the receiver based on the channel data passed as part of the protocol setup - but as it is proprietary, I don't know. If the S/PDIF transmitter is working within the tolerances allowed then the results should by definition be idential.

It would be interesting to hear of properly conducted double blind tests done on self-styled audiophiles to see if this is the case. I don't think any such work has been done in controlled conditions as the market doesn't need it.

(Edited to correct my mis-remembering of the S/PDIF spec, I was thinking of something else. Oops).

The point of using "digital" is to make sure that the information can be copied without loss. If you mean that the transmission of that information may be unreliable, then I agree. I cannot however let that statement go that copying digital data is lossy in anyway at all.


I think I did cover that in my example of copying WAV files; that if it was just a matter of copying data files then it is an identical copy. But of course digital audio is sent, as Nick points out, using timing info, and it's this variation that causes problems. The old SDIF-2 interface had seperate left & right feeds, and needed an additional word clock signal; diconnect that, or mis-clock it, and you got clicks all over the place.

OK, I have now been reading more. One site in particular is interesting, specifically these two pages:

http://peufeu.free.fr/audio/extremist_dac/bit_accuracy/

http://peufeu.free.fr/audio/extremist_dac/spdif.html

The latter leads to another paper on the "Specification and Assesment" of jitter. I would paster the two paragraph conclusion, but the text is locked against simple cut'n'paste.

http://peufeu.free.fr/audio/extremist_dac/files/jitter92.pdf

While I am coming 'round more to the points being made, I still think that much of this is snake oil - not all, just most. I do not buy mains cables to make my music sounds better nor believe the magazines that say that one optical cable is better than another. I do believe that a better quality (not more explensive!) system can produce better sound that a badly made one - but I cannot accept that if you send the same bits (timing included) to a well-designed DAC you will get different results each time you play something; but if you hear better music from one setup vs. another, then good for you! Each to their own.

My initial thoughts about digital audio were that bit errors were partially responsible for audio quality degradation, but after talking to people that know, I'm satisfied that this isn't a significant factor.

It is just down to what amounts to phase noise in the timing information, and the unfortunate architecture of modern digital audio equipment makes this all the more significant. Professional digital audio has long used what's called a "DAC master" configuration, where the master clock in the recording equipment is based at the DAC, and all the other equipment is slaved to, and synchronised with that clock.

Domestic digital audio equipment unfortunately uses a transport master configuration, where the whole system is slaved off the master clock in the disc spinner. The timing information from this clock has to find it's way to the DAC, because that uses the word clock timing info to define the point in time where each amplitude sample is reproduced. If that pulse (which is encoded in the SPDIF timing info, along with the bit clock) arrives too early, then the next analogue amplitude that is created by the DAC will be produced too early, and so on.

It surprised me that that's how it works, but it appears to be correct in almost all cases. I imagined that the DAC would use a filtered phase-locked loop to recover the intended timing info and reject the jitter, but that's not the case. A few audiophile DACs do this, but it's difficult and expensive and get it to work right, and all too often, much of the jitter just goes straight through, plus a bit more for good measure.

I've done a lot of research on this; had to change a few pre-conceptions, and learned a great deal on the way. Everyone initially thinks "bits are bits", but that approach only allows you to re produce the amplitude information correctly. Timing has to be right too, and that is not conveyed with digital coding - it's analogue, and it comes from the variation in the point in time where each bit transitions from one state to the other.

I'm deeply sceptical about snake oil, and I will always try to find ways to account for the differences that can be heard between audio systems, and trust science to explain those differences. However, if something specs and measures the same, but sounds different, that just means that you haven't understood everything that is responsible for quality, and need to look harder for better measurements. Jitter measurements do give a good indication of digital audio quality, though I think it has to be understood that it can't be characterised with just a single number; there's more to it than that.

What is surprising is that as little as one nano second of jitter can cause an audible degradation, but it does. I hate to say it, but optical and coax cables also affect quality, but we'd better leave that for another time! It's definitely not snake oil, though!

regards, Nick

Back to my original thread... I've just finished watching 'Cars' on the Sony HS50 projector.

Oh dear... If ever a film was made to show the Chroma Bug, boy this film is it.

I can absolutely confirm that the Denon 3930 suffers very badly with the chroma bug in every mode except 720p upscaling or 1080i/p upscaling via HDMI.

The component output (in either interlaced or progressive modes) suffers, and so does HDMI at 480/576i or 480/576p.

I now feel I need to change my projector for the reasons I gave earlier... i.e. the HS50's blanking problem with 720p.

Maybe I should consider a Pearl... but damn, if I hadn't bought the Denon 3930 I wouldn't be in this position.
I should've kept the A1 !

Just a warning for prospective Denon 3930 purchasers... if you can't make use of the HDMI upscaling, or intend to use it in a dual display where you will be using the component connection as well as HDMI, then think carefully.

Denon need to release a firmware update to address these problems... but then no suprises there eh? They have a habit of doing this.

You don't see the chroma bug when upscaled to 720p / 1080i over HDMI? That doesn't seem to make sense. Can you describe what it is that you see? The chroma bug is an MPEG 2 decoding fault that the rest of the replay chain is saddled with. The only way to deal with it after it's out of the decoder is to apply vertical chroma filtering. Some processors have an option to do this, but the inevitable consequence is reduced vertical chroma resolution. If it is truly the chroma bug, then upscalling should make it look worse unless it applies filtering before scaling. That seems unlikely; players are usually guilty of edge enhancement rather than softening when upscaling. I don't think a firmware release wil solve thisovernight. DVD player makers have been trying to erradicate the chroma (and ICP) bugs for years....

Nick ???

Back to my original thread... I've just finished watching 'Cars' on the Sony HS50 projector.

Oh dear... If ever a film was made to show the Chroma Bug, boy this film is it.

Is this a PAL DVD? Are you sure the DVD is flagged as progressive? If a DVD is flagged as video, but is in fact transferred from a progressive source (ie. film) then the chroma bug will be visible, but this will not be the fault of the MPEG decoder. MPEG decoders use the flags to decide what kind of chroma upsampling to do, so even 'Chroma Bug Free' decoders will show CUE if the DVD is flagged incorrectly.

I mention this because leaving DVDs flagged as video when they should in fact be flagged progressive is a common ocurrence with animation. It also happens a lot with TV programs released on DVD. It is assumed that because a program is on TV, then it must be interlaced video, when in fact many TV programs are shot progressive these days, or they are already deinterlaced in post processing.

I hadn't heard that before.

I thought the chroma bug was a done deal BEFORE the video gets to the de-interlacing stage, which always follows the decoding.

I'm not talking about deinterlacing. The progressive flags aren't just used by the deinterlacing chip. They are also used by the MPEG decoder to determine whether to do progressive chroma upsampling, or interlaced chroma upsampling. If the flags are wrong, then the decoder will do the wrong upsampling even if it is a CUE free chip.