Jstropp - read my user name. Please improve the situation - how exactly is music represented digitally? |
Jstropp,
Please name names! |
There are obviously some on here that do not know how music is represented digitally. |
"Does it follow that some digital cables are better at delivering digital signals free of or with less added jitter?"
I cannot speak for K. but clearly there are always differences between two products. The question is more how much these matter in practice. I tend to think that any good quality product will deliver excellent results for most people in most cases. There are probably always exceptions though.
"On a related note, in theory or in measurement, can a digital signal be corrupted in a cable, say due to exposure to strong EMF, to the point where 1s and 0s are actually deleted or unreadable at the DAC. I.E. outright data loss?"
That's a good question. Of course it is possible. DIgital gear is inherently a source of noise and may be affected as well. I think the former is a much bigger problem than the later. I encounter it to a great degree with my setup. Noise control is important. SOme wires may shield against it better than others and I think that can make a difference in most cases where detailed listening is involved. |
Kijanki, let me make sure I am tracking with you. You are saying that jitter is important. That jitter can also result from cable induced errors. That re-clocking at the DAC does not necessarily correct for all/any errors related to jitter that could occur during delivery of the raw digital signal through a cable. Does it follow that some digital cables are better at delivering digital signals free of or with less added jitter?
On a related note, in theory or in measurement, can a digital signal be corrupted in a cable, say due to exposure to strong EMF, to the point where 1s and 0s are actually deleted or unreadable at the DAC. I.E. outright data loss? |
Mapman, you are testing my memory. I believe they were all 1.0 m and all in good condition. The brands were Elco, Legend(?), Virtue, Monster, and some unknown cable. The Elco was the best. |
YEs, asynchronous USB is the other key technology, especially I think if a general purpose computer is the source for streaming to DAC and maybe also if one wishes to push the limits in regards to high resolution digital audio files in that this is a newer technology than traditional SPDIF/TOSLINK. Maybe. |
I second Mapman's recommendation of network streaming. Computer speed, amount of RAM, playback program, file format etc. make no difference since timing is recreated on the other side of the bridge (saves a lot of money). Sound still can be affected by ambient electrical noise but in this respect slow computer might be better than the fast one.
Asynchronous USB should be good as well since, as name suggests, it does not use noisy/jittery timing from computer by buffering the data and requesting different amount of samples each frame to keep buffer between underflow and overflow. |
Note that the architecture used for digital streaming can be a variable in determining end results, but I find if done well a certain way, then the wire between the source and DAC seems to make little difference, as long as of good quality, and perhaps not too long as Kijanki suggests.
The architecture I like is wireless network connection from server to streaming device (for physical and electrical noise isolation from potential noisy commercial computer gear), and SPDIF/TOSLINK from streamer to DAC. Most network streaming devices buffer data which help to avoid timing issues at the source.
Then choose your DAC of preference for the sound you like. If it does reclocking very well, then that is an extra insurance policy in case of any doubt. The trend seems to be for more and more DACs to do this these days.
THen use a good quality digital wire that is not too long and you should have all teh bases covered. |
My system images and does detail very well, with detail as good as most any of the best headphone setups I hear or my phono source, essentially as best I can tell. IE no detectable issues ommissions, flaws, etc. So I am sure jitter exists and could be made better (nothing is perfect), but impact in my case to-date is just not an issue.
Of course, although I am always listening to various things to know better, you never know for sure what you may be missing until you hear it, but I do listen to a lot of music in various ways enough to be able to make a good determination whether things are going well or not. |
Knownothing, Imagine that you play clean 1kHz sinewave but digital stream jiters in time back and forth at 60Hz. It will result on analog side in expected 1kHz signal and two other signals (sidebands) at 940Hz and 1060Hz. Their amplitude will depend on the amplitude of time jitter. These sidebands will be at very low level, in order od -50dB but still audible since they have no harmonic relation (like overtones do) with original 1kHz tone. It is form of modulation (similar to FSK). While music has many frequencies time vibration (jitter) of the signal appears at many frequencies, together causing whole bunch of new frequencies - a hash. This has has amplitude proportional to sound level and is inaudible without signal. It will make music less clean, imaging less precise etc.
Mapman, very short coax should be free from reflections. Rule of thumb says that to avoid transmission line effectes (reflections) use cable so short that propagation one way thru it is less than 1/8 of transition time. Assuming average transition at 25ns it will be <3.125ns equivalent to about 2ft of the cable (propagation = 5ns/m). Since it should include internal connections in transport and the DAC I would not risk putting more than 1ft. Longer cable might cause reflections and to avoid first reflection affecting first transition cable has to be longer than about half (threshold point) of this transition 25ns/2=12.5ns. At 5ns/m it will be 2.5m and since it is both ways 2.5m/2=1.25
It shows that 1.5m or even 2m cable might be better than 1m.
I said might because nobody knows exactly what transition time is so it is pretty much trial and error. If your fancy transport outputs 5ns transition it will give you great immunity from electrical noise affecting transition time, but will require well matched characteristic impedance to avoid reflections. Toslink is immune to ambient electrical noise and does not produce transmission line effects but driver transitions are slow making it more sensitive to system noise (on both sides). |
It seems to me that this is more of an issue with data loss than it is with timing errors, although I have read in other threads RE transport quality that re-clocking can only go so far, and that the more conservative the initial translation and transport of the digital signal, the better the outcome, even with the most successful implementation of re-clocking on the DAC end of things. |
"Mapman, are you saying digital signals in a coax cable for example are harder to mess with than pure analog signals, and so theoretically the cable construction should have less impact on the resulting sound?"
Not harder to mess with per se but I have not found any clear negative effects to date whereas I have with analog ICs and power cords. ALso I find less differences with speaker wires though I know all these things CAN make a difference. Just to different degrees for me in practice to-date.
I do find USB implemetnations more problematic for CD res digital than SPDIF/TOSLINK. Have just started to dabble with USB. USB has different modes of operation that clearly can make a difference. Asynch mode is preferred for best sound quality. I use HDMI in my AV system but have not experimented there at all to-date. |
Kijanki,
You use the BEnchmark DAC which pretty much deals with any jitter issues that might exist otherwise, correct?
I do not have a DAC like that to-date and am probably more affected by the variables you describe, but still whatever differences might exist in my case still is way down in the pecking order of things that make a clear marked difference. It's been a case of theory not coming into play yet clearly for me. Someday I might a DAC like BEnchmark that addresses jitter comprehensively and see what happens there, but have not crossed that bridge to-date. |
Mapman, are you saying digital signals in a coax cable for example are harder to mess with than pure analog signals, and so theoretically the cable construction should have less impact on the resulting sound? I.E. It is harder to mess up coded and sent 1s and 0s than the analog wave forms of a bass drum or a cymbal in transit through a wire. I have found differences in the sound performance between different USB and HDMI cables, but those are different animals than coax.
kn |
It is a system thing. Cable that works perfect in one system might be bad in another. It comes to characteristic impedance matching and quality of the shielding. Characteristic impedance is affected not only by geometry of the cable but also materials. Anything that changes inductance or capacitance of the cable might change characteristic impedance resulting in reflections on impedance boundaries producing jitter - adding noise to music. |
I am with Mapman. If I remember right the 'digital' in digital signals means digits. And we have 10 digits on our hands right. I think the signals are sent by sign language. Well the, they would sound different depending on how good of a signer sends the signals. Elementary Watson. Hope that helps. Signing off from mooshound lodge for now. If you don't find me handy hopefully you find me funny. Don't worry I kept my day job. |
Mapman, to cut to the chase, at least in my system when I had a digital cable, copper outshone silver, whereas for the interconnects it was vice versa. Both the interconnects and digital cable were Audioquest Lapis Truth, same construction, dielectric, etc. Just the conductor was different. YRMV. |
"The digital cables are carrying "analog" signals."
Yes, but the signals are completely different in design and play by a different set of rules. |
The digital cables are carrying "analog" signals. They're all analog signals. You didn't think they were carrying 1s and 0s did you? |
****The irony is that silver is the worst conductor for analog signals (at least to my ear)****
Not quite. Silver is the worst conductor for analog signals because of the way that many audiophiles tune their systems. |
To my ear and eye solid silver wire sounds best for digital signals. You only need to see what a solid silver HDMI cable does for a plasma TV to know. The irony is that silver is the worst conductor for analog signals (at least to my ear) |
Gentlemen, this thread is nearing 14 years old! Shall we bake a cake? |
Kijanki, I am with you to date in terms of not hearing any noticeable difference using various cables with various sources. I also compare to phono source in my system and find most any good quality digital wire tends to work similarly well. |
Mapman, I couldn't hear any difference between CDP (coax) and Airport Express (Toslink). I've never tried different brands but compared very short (<1') and 2m long generic coax (self made) and couldn't hear any difference.
Now my CDP is a cheap Blu-ray player wired thru my TV (HDMI) to Benchmark (Toslink) and I still cannot hear any difference switching to AE. It is possible that Benchmark's jitter supression is good, but unfortunately it can also mean that my hearing is not that good. Either way sound is very clean and smooth suggesting no jitter presence. |
Kijanki, I am also interested if you hear differences using the same source with different cables and your jitter resistant Benchmark DAC. |
Jim, can you provide more details? What kind of digital cables? How were they different? Construction? Length? Brand? How did the one sound different? Better? Worse? Did all seem in good condition?
I'm still trying to find out what does matter most with these things. Length is one factor that I have heard can make a difference alone. |
A friend lent me 4 digital cables. 3 sounded the same but one sounded very different. You just have to find there "one" |
I am convinced that digital cables can make a difference, but in practice to date, I find that the differences attributable to cables I have used alone are not nearly as significant as many other factors and that once I have a handle on the big fish I do not find much to inspire me to tackle testing different digital cables alone. Its just not been worth it in my case to date, not to say it may or may not be for others. |
Some people, convinced that digital cables cannot make any difference, claim that people who can have to be under influence of placebo effect. They don't realize that their strong conviction makes them unable to hear the difference because of negative placebo effect. |
I agree with Frogman, If someone claims they can hear the difference and are willing to spend the money, Thats great, it's their money and ears. I for one, do hear differences. I have had to train myself to UNDERSTAND what i am listening for. For example I find that evaluating spdif cables is way different that evaluating IC's. Also, I have compared speaker cables where I heard minimal differences and returned them so sometimes you win sometimes you lose. |
****"Why is it so darn difficult for some people to accept the simple fact that some listeners have better hearing ability than others; wether because of physiological differences, experience, or training? "
ITs not hard to accept that, but knowing who those people are for sure can be a challenge.****
Does it really matter who those people are? Seems to me that if we accept that simple reality, then one can go about the business of trying this cable (or whatever) or that cable to see if we can hear those differences; and if those differences constitute an IMPROVEMENT in our estimation. Bottom line: we accept that differences exist and if someone else wants to kid himself about a particular difference, who cares? The key is to keep an open mind about the possibilities. If we can't hear a difference we should just move on. We spend so much time disputing what someone else claims to hear. Why? |
I don't think it has anything to do with being smart or not. It the way our brains work, including mine. We all think we are the exception to the rule. |
Mcel,
Most of the people here are pretty smart. Do you really think that they think that?
There are many other reasons as well why someone would choose to ignore those things.
But the bottom line is, if they do, then take everything said with an extra grain of salt or two. The reason why they do does no really matter much then. |
Mapman - it doesn't help that the vast majority assume themselves to be immune to placebo and the power of expectations. It is alway blamed on inferior hearing and the number of audiophiles that believe they heard something and then later convinced themselves otherwise is approaching zero. |
"Why is it so darn difficult for some people to accept the simple fact that some listeners have better hearing ability than others; wether because of physiological differences, experience, or training? "
ITs not hard to accept that, but knowing who those people are for sure can be a challenge. |
I agree with you Kijanki. I have a dual band router as well but cannot use the 5ghz signal because it simply is too weak. My wireless router is upstairs and my listening room is downstairs in the corner of the house. That said, I believe you can still get a strong, reliable signal from 2.4ghz. Most people do not change the default channel on their wireless router. Just changing my channel greatly increased not only throughput but also reliability. For those who are having wireless issues on their 2.4ghz band I highly suggest playing around with the channels first to see if it solves the problem. |
Mceljo, there are only 3 non-overlaping channels in 2.4GHz WiFi. My microwave operates on one of the channels interrupting my music while neighbors operate on two other channels with routers most likely set to max power. I switched to 5GHz. It gives me 23 non-overlaping channels, practically nobody uses it (not very popular), no sources of interference, and poor penetration thru the walls keeping offending signals (if any) away.
I bough 5GHz WiFi USB adaptor for my old MacMini and dual band Linksys router. Receiver (Airport Express) can receive both 2.4GHz and 5GHz. No more dropouts. |
My understanding is that the necessary functionality to decode the digital signal on the receiving end is a macro function compared to current digital technology. I may not have really poor vision, but I can still tell when it is day vs. night with ease.
I can understand a little of the timing and jitter discussions, but when using an asynchronous DAC there should t be any concern about data loss prior to the DAC, right?
I find it ironic that we assume some level of signal degeneration when using a digital cable, but trust wireless connections to do the job. When my wireless connection has a transfer issue there is a distinct pause in the music. |
I recently sampled about 5 rca spdif cables, one really stood out head and shoulders above the rest. However the rest were pretty similiar. |
It's not only circuit components that have impedance All cables also have an impedance value, called characteristic impedance.
Different cable = Different valve = different sound....
Let's hope this helps. |
Ladycharnet from 12-19-12 FTW!!! |
One factor I have observed with the optical cables I have used is that the bandwidth of the cable plays a significant role in the sound reproduced.
I have three basic grades..
1. Consumer grade - unknown bandwidth, but definately the least accomplished performer
2. A medium bandwidth cable rated at 50Mbps
3. A high bandwidth cable rated at 150 Mbps
The difference between these three are clearly audible in the micro details that become more pronounced as each grade is installed.
The specific micro details are those that contribute to the acoustics of the recording venue - not so much the actual musical sound or tone.
The difference when #3 introduced was very noticeable - so much so I immediately purchased a second cable for my A/V system which made a huge improvement to the spacious aspect of the system.
To this reader at least, there is a difference, which I attribute to bandwidth, but this can be attributed in turn to the slew rate and other technical attributes of cables cited in the many prior posts.
The faster a cable can respond to going from a 0 to a 1 (i.e. higher bandwidth) allows more "data" to get though to the DAC, which in turn produces a better analogue waveform with fewer interpolated distortions.
Maybe build quality is also a factor, all I know is - it sounds better :-) |
Ethernet has VASTLY improve bit error correction chips. Audio DACS benifit...a LOT from this. A one or a zero has no sound, it is just a toggle of logic a DA converter uses to construct the analog waveform.
Missing bits are "filled-in" and interpolated between bits for an analog signal. To that end, the analog circuits are what we "hear" if all the bits get through (and they do to a crazh high level of perfection!). So my ears tend to say that the analog waveshaping circuits don't all make the same decisions with the same bits. |
I have to admit it, I love this thread!!! |
As usual, when I explain audio cables, I remind everyone first exactly what is "the scientific method". As an engineer myself, trained in science, I don't try to explain anything until AFTER I have conducted a test, using my senses and my powers of observation to determine the human response to an issue. Then, and ONLY then am I ready to search for the explanation of why these observations occured. As scientists, we NEVER search for an explanation first, then force ourselves to observe what we logically determined to be true before-hand. So, the answer to "do digital cables sound different" is 100% in the ears of the observer. Then, the EXPLANATION of why must be consistent with that subjective experience. In other words, I listen first, with a complete reliance on my subjective ability to hear any difference. Then, and ONLY then, can I create hypothesis to explain why. |
If a person Pays $5000 for a cable, they are going to have higher expectations. They sound better because one expects it to sound better. |
Why is it so darn difficult for some people to accept the simple fact that some listeners have better hearing ability than others; wether because of physiological differences, experience, or training? |
Having had Audioquest Truth solid copper conductor with air dielectric and Audioquest Truth solid silver conductor with air dielectric digital cables for comparison, it was obvious, in my system at least, there were important differences in how they sounded. |
A topic that's been beat to death, but IMO there is no audible difference between one digital cable and another. One toslink optical cable works just as well as another for carrying bits. Same with coax RCA. Same with balanced AES. Same with USB. Spending more than $20 on a digital cable is money down the toilet, and anyone who claims they can hear a difference between two different brands is full of baloney. |
