In reply to:
Now, the preamp sucks up the bits (which cannot have bit-skipping like you said) and puts them into its
DSPs and then on the DAC which all run of its internal clock which is very high quality (maybe your companies ;-).
Not likely. When I say the best, I'm talking about 12GHz clock distribution chips with jitter below 200 femto-seconds... I doubt they have a need for anything remotely that precise.
nope, I was told that good ears hear waveform differences caused by patterns of couple of pico-seconds deviations
but femto, I pull my hat off, that's what, fractions of inches for light in this time ;-) You guys must have fun, sounds
bleeding edge.
In reply to:
Now, if the DAC has jitter, I see clearly how that can screw up the resulting wave.
The clock merely tells the DAC at what pace to perform its activity. The DAC is not operating very fast so you'd have to have jitter at such a proportion to matter to that device as to make the chip misstep. A high bit rate 24bit 96kHz DAC is representing a piece of data in steps of 1 point per 10 micro seconds. Your everyday standard, and very cheap Silicon based clock generator has jitter in the nano-second scale.
You're at least 1000 significant figures away from a timing problem...
Incidentally, this is also why jitter isn't much of a concern to digitial designers until they get into the >500MHz range at the very least and really not more than 1GHz.
so, not sure I follow here, so if you say that I reconstruct something around 10kHz with 10 microsec clock (that's 1e-6 if I'm correct) (which means I'll need at least 20kHz samples to do it anyway decent, that's 1/20*1e3 = 0.5 msec = 500 micro seconds so 1 microsecond clock jitter could be already 0.2% difference on the timescale). Could we hear that one ? My experience with image processing (was a hobby long time ago) suggests to me that just couple of those are surely not to be heard but if such difference happens in a predictable pattern like jitter on another pattern (like music material) I can easily imagine we are able to tell recognize it's going on in an incredibly exact fashion
(analogous to e.g. human eye being pretty
weak with colors, we only see couple thousands if I remember correctly but once we put them close to each other, we can differentiate millions of hues demonstrably). If you think I'm off the charts, read
the reports of NASA that for I think 10+ years thought that astronauts lied their teeth off when they were saying they can see single cars from orbit (it's _way_ beyond the resolution of human retina). They found the explanation, it
makes you shake the head in disbelief as to the accuracy of human senses.
But the core of the problem you didn't mention. What you talk about here is to just make the clock on the DAC very precise, I understand the benefit that it may or
may not bring. I don't understand why there is a claim around that sync'ing the clocks between the transport and the pre-amp should buy me anything. The clocks are
independent and there is a buffer inbetween so the effect should be zero, is that what you say ?
In reply to:
But lots
of people with a sound clue say that clock-syncing the TacT
and the CD transport improves the sound significantly (including the guys that developed tact ;-). And funny enough, I _believe_ to hear the effect they describe as digital jitter effect. So why should that be if not digital clock jitter from the CD transport somehow affecting the DAC or DSPs in the preamp ?
Lots of people who are considered experts claim you can improve your sound with $2000 digital interconnects. ;-)
I just bought 190$ silver interconnects. Just for the kicks ;-)
That doesn't mean its true. Our brain is FAR more complicated than we give it credit for.
agreed.
It's ability to affect our perception of the world is phenomenal and shoudl always be taken into consideration when discussing such things.
agreed even more. If you want to see something in the audio-visual space that makes your jaw _drop_ look up the work that's going on in
language acquisition. There is a video done in canada or US (some woman I forgot the name off, she's a big shot in children language
development world, Patricia something) where a face is saying a sound [one of the anchor sounds of english language, like 'ka'] and the sound playing does
another key sound like 'ba'. When you close you eyes you hear 'ba', when you open them and see the face you hear yet a completely different
anchor sound, 'fa' or something like
that. It's below conciousness, you can't influence it and the effect is very distinct. As to why, they don't know ;-), obviously the sound we hear
is being modified in the brain by the visual circuitry before it even goes to the cerebreum. So yes, we warp reality unbelievably.
That said, if you're happy with the results and are perceiving an improvement, that sounds good to me. All that really matters in the end is whether you enjoy the results. It seems clear to me that you do.
yepp, I wish I would do double-blind-testing but frankly, I'm too lazy for that and probably rather spend $1K on clock sync to see whether I _believe_ it improved the sound.
Much more fun that way, I'm dealing with commercial, analytical, exact, unforgiving science every day at my job, this is a hobby and it should be a little voodo ;-)
In reply to:
And last, in all respect, It would hurt my ears tad less if you didn't try to go into offensive that quickly on your posts.
I'm sure I know much stuff you don't know and vice versa. This forum is to have some fun, learn and discuss, not to prove who's bigger ?
This is brought to my attention fairly often on this site. I really don't understand the nature of it. I'm not intending to be abrasive and I've actually been trying to pad my posts with hugs and kisses in order to temper the problem some here have with them. I certainly don't mean for you to interpret what I say as offensive or hurtful. Can you point out specifically what gave you this impression? By my eye, I'm just direct and perhaps lack a little warmth in computer correspondence due largely to the fact that I'm staring at a cold piece of machinery.
Having fought that problem for a long time in my life (and still doing so) I extrapolate that you're a very knowledgable individual who cares very deeply
about his work or area of expertise and who considers 'truth' as
seen by you overriding any social norms which are of course just 'agreements' and not hard axioms (albeit going into greeks I realized
that moral and ethics are basically axioms that allow society and therefore not different from axioms that hold math together. Even deeper here,
I assume you are familiar with Goedel and Wittgenstein and the conclusion I had to draw from their work [one mathematical, the other philosophical]
that math is as arbitrary and unprovable system as society with contradictions being the nature of the beast in the deepest meaning of its sense ;-).
On more tactical terms, telling people straight on they have no clue what they talk about seldom furthers your cause as isn't lack of modesty as isn't
the claim to be the bearer of the truth. I tend to either patiently explain over and over or walk away from forums like that when I tense up and feel
that 'there are too many nuts' or when I feel the competitive edge coming up. And yes, electronic mediums warp things to the worse also often ;-)
Anyway, thanks for good input here
-- tony
