How did I miss all this, sorry cant help getting stuck in here. Please lets keep to the facts and keep personal insults and jibes out please. I am always keen to stir up debate but this doesnt need inflamatory personal remarks to get points over.
A few comment and additions on the technical front to set right inaccuracies.
Originally posted by Cream
It happened to me (yes even me ) when I got my first AV amp. I was comparing the difference in the soundtracks on Gladiator, and I tried DD first, and then dts, and as Maximus's hand is brushing through the wheat at the start I was thinking "oh yes that's a lot better, there's much more detail in that sound than with DD" and then I noticied the status display on the amp and realised that I hadn't selected dts properly and it was still on DD. Because I was expecting a difference I heard one.
Cream, if you are demoing Gladiator on you first AV amp then you are hardly a long tem user with a wealth of experience then? Those of us who have used PL since their launch (in its previous names and incarnations) have nothing to contribute? There are some very experienced people out there, many who have contributed to this thread already. There is more than one God out there you know
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Originally posted by hermand
i.e. if we accept this is true, then surely it makes no difference to the sound quality (with DD/DTS) what dvd player you have sending the digital signal to the amp/decoder. Therefore a £4000+ Tag DVD32R will sound the same as a £100 Dansai 852 if they are connected to the same amp/decoder. The only way this is not true is if
(a) bobones is wrong, and jitter does make a difference to DD/DTS
or
(b) The stream of zero and ones is different (aside from jitter) - is this possible from a given disc?
Lets put the record straight. Jitter does make a difference to DD/DTS as well as PCM. The effect is more noticeable however with PCM signals. You have only go to try this out on the above mentioned Tag DVD32R with or without the jitter reducing sync link or a jitter reducing DD/DTS aware re-clocking box. Jitter can be a killer to sound and is the single reason for the death of off board DACs in all but high end kit, where proper jitter reducing solutions can be effectively engineered (sync links, N Code, C code etc NOT PLL etc).
Every DVD / CD player I have ever come across can output the correct 0s and 1s. This is not what is in issue here. The digital interface has the ability to transmit other things other than the digital bit. Uncle Eric has eluded to this already.
Many convention solutions to jitter problems have actually made things worse rather than better just because they tried to solve a problem they didnt properly understand. Just look at the poor grounding arrangements for the early reclocking boxes! A disaster area until people cut tracks! High bandwidth SPDIF connects might not be the right way to go for good sound as they also transmit all the nasties as well. Limit the bandwidth and much can be filtered out naturally whilst still getting the 0s and 1s through (why Toslink optical connections often sounds better on HCPCs and cheaper digital products?). Similarly, rise time isnt necessarily better being faster. There is much more to this argument than first appears re the right 0s and 1s are getting through so nothing else matters. The 50p coax 75ohms (well screened I hope) is all you really need to get the signal into the processor. There is a big difference in the construction of these and proper screening and termination is very important. If you transmit nasties as well as the 0s and 1s some amps can deal with these through filtering. Others may well be overloaded by these non 0s and 1s type signals, adversely effecting the sound. They both have the same 0s and 1s however. Optical isolation may be a neat solution however.
It is all down to how you engineer your transmission standard. Personally for basic / standard kit (inc HCPCs), where there might be loads of nasties I recommend Toslink, as the optical connector can offer some isolation. Please spend some money on a decent one however as cheapo ones suffer from breaks and reflections that cause more problems than they solve. For better quality kit where the kit is more resistant to out of band nasties, then a well screened and terminated 75 ohms coax is all you need. I just wish people would use BNCs rather than RCAs which cause their own reflection problems! RCAs are not 75 Ohm connections for soldered cable where BNCs can be. Whether this is a 50p/m DIY or a £40 off the shelf unit is down to personal preference / DIY abilities / time. For those who want the best signal transfer the AES XLR balance 110 ohm works very well when correctly terminated. However my favourite connection method is wideband ST connectors just because it is a quality engineered interface rather than the compromise fudges that we more normally have to deal with. The latter two interfaces have the advantage of being able to work over much longer distances effectively.
Why is the Tag so highly spoken about? The Tag DVD transport has jitter levels from DVD as low as the BEST single box CD players. Just look at the Miller test results and yes it can do this with a 50p/m 75 ohms well screened coax!
Dont forget that many of the techniques for reducing these nasties are actually power supply mods! We are back to Kimber weave mains cables and screened mains cables. Cable is cheap and is one of the smallest cost in manufacturing a quality lead so dont get too hung up on 50p/m figures. A £90 lead will probably have spent no more than £3 on the cable. Quality plugs, quality solder, expert manufacturing all cost money long before people start putting their mark ups on the cable.
Yes some of us do have some qualifications!