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Post by optical on Jun 8, 2021 14:41:01 GMT
Hi guys, couple of questions here.
How much difference does the plug on a digital (coax) interconnect make? Logically it's job is simply to lock onto the socket but would using pure copper aid with signal transfer or is digital signal just that?
Also what are peoples thoughts on single solid core vs stranded wire for digital signal transfer? Single solid core would logically do the job better (to me), but I'm sure there are many factors to consider here like bad RF rejection/capacitance/impedance etc. Assuming both cables have good foil/Teflon jackets etc.
I'm wondering if it's worth taking a punt on a nice OCC 75ohm cable with some pure copper plugs, but may not be any upgrade over my QED reference 40 cable.
Cheers
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Post by macca on Jun 8, 2021 15:38:48 GMT
Any cable is capable of of picking up noise, the 'digital' signal still uses electricity just like an analogue signal so keep any type of signal cable well away from power cables. But different connections make it sound different? I'd say no, there's no way that can happen. Other points of view are available
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Post by misterc on Jun 8, 2021 16:02:41 GMT
Hello Optical I could go into great detail intp impedance mismatching, and transmission lines errors causing issues, however just use Farnel/RS/Etc for some RG59 coax and some Canare 75Ohm plugs and you will feel happier. All for under £40
For love or money I could not find the post I made on here sorry
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Post by antonio on Jun 8, 2021 23:35:13 GMT
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optical
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Post by optical on Jun 9, 2021 6:30:00 GMT
Hello Optical I could go into great detail intp impedance mismatching, and transmission lines errors causing issues, however just use Farnel/RS/Etc for some RG59 coax and some Canare 75Ohm plugs and you will feel happier. All for under £40
For love or money I could not find the post I made on here sorry
Hi Tony, thanks very much for that. I actually remember reading through it a few weeks ago (and doing my level best to digest it!) so upon second reading I'd like to think a bit more has gone in! It is very interesting seeing the actual peaks and deformities created on a scope rather that assuming audible degradation. I'll have a look at your recommendations, cheers
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optical
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Post by optical on Jun 9, 2021 6:38:30 GMT
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Post by misterc on Jun 9, 2021 8:42:54 GMT
Just an interesting side piece to this, a couple of weeks ago I asked a couple of customers to try a digital clock cable for me (a 75ohm with bespoke crimp BNC terminations) The cable in question is a a very well respected test and measurement reference cable @ 75Ohm (most are 50 Ohm impedance for this area of electronics) it has 18Ghz of bandwidth and an ultra low insertion loss, we use it for a lot of digital audio measurements. It is a very accepted T&M standard It has from a visual perspective an almost 'spot on' waveform with very small 'gibbs ears' until you approach the bandwidth limit of your instrument (not to many scopes with a BW of 18Ghz even these days, unless you are a large R&D company of Government body!) Even mine doesn't hit that limit My point being is you can 'see' the differences in waveform make up clearly, and yet from long time experience both imperially and lab wise, you do not always obtain a correlation bewteen perception and reality with listening imho If I get time later I will post some examples for you.
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Post by antonio on Jun 9, 2021 11:03:23 GMT
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Post by antonio on Jun 9, 2021 11:14:29 GMT
'MisterC', don't forget to report back and let us all know the results of the listening tests, and more importantly, the name of the cable
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Post by misterc on Jun 10, 2021 8:21:23 GMT
'MisterC', don't forget to report back and let us all know the results of the listening tests, and more importantly, the name of the cable Hello Antonio Here is the feedback from the customer regarding the T&M cable, he was using a highly regarded branded American cable around £1200. "Good afternoon Tony, Very interesting listening to how much Clock cables affect sound quality. The immediate impression of the reference cable was of increased focus on the sound of individual instruments, they became more seperated and coherent. Similar to the effect of getting a more pin sharp image in a photograph. The most impressive effect was on vocals which lost any degree of harshness and flowed easily, very natural. There was a similar effect to adding a grounding box in that some of the higher frequency attack of acoustic instruments was slightly blunted. Perhaps I am describing a lack of glare, I don't know, but I preferred the more raw sound .Overall it seems to reduce the dispersion of the sound and concentrate it in one place. I did put it on the first Mutec in the chain with little effect to be honest."
The cable he tested was made from this companies products. I have around 20 of these in the lab they were between £270 and £600 each depending on connector quality, termination and length. Fortunately at the moment 18Ghz is high enough for our work! Quality coaxInteresting read for youI have demonstrated this cable to many audio chaps it surprises them shall we say. I am not saying its the best, what I am saying is for most people it will outperform all of the usual cable suspects up to £1K imho
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Post by antonio on Jun 11, 2021 1:12:44 GMT
Good Morning MisterC, Thanks for the feedback, I had to do some research for my brother, and did read the comparison of cables you linked to, it's very good, but to be honest I don't think my ears are good enough to hear the differences that gentleman heard. I will say it did get us interested in Snake River Audio, although at the end of the day he purchased two Nordost Silver Shadow BNC cables from the States at a good price, it's an older model cable, but was given very good reviews at the time. I have not heard these yet, but my brother felt there was a subtle improvement over his standard dCS cables. I see you are doing different lengths, I quoted to 'Optical' on here, hope they will be 1.37m, I got this from the SRA Boomslang information , don't know if there is any truth in it, but my brother only needed 40cm's, but purchased the standard 1m cable.
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Post by misterc on Jun 11, 2021 7:40:59 GMT
Hi Antonio
Cables lengths do seem to stir emotions within certain audiophile communities, I have a few customers who will not purchase a mains cables unless its two meters long I kid you not, all because of a certain magazine review a number of years ago.
Without question you would observe a difference in these cables make no mistake, especially with in a well set up system (not necessarily costly) as to whether you would feel its 'better' then that is for you only to decide.
The chap who sent in that feedback is 64 years old and has zero DCS in his system, a well respected integrated amplifier and Focal Utopia speakers MK III.
I have around 20 of the stock dcs cables with the gold plated ends, these are basic RG59 coax units for around £20 each.
From experience within a DCS set up just using the stock Vivaldi clock, you gain more upward performance from choosing the correct digital AES interconnect then spending lots on clock cables, I am not saying they do not make a difference, just not as much as the digital audio data stream imho. Its a cost Vs potential uplift in the sound each individual is different as will make their minds up accordingly
Once you have upgraded form the Vivaldi clock (which in reality is quite average, then I would certainly look at changing the clock cables.
I know a fair number of 'full stack' DCS owners that the full front end cable outlay is at least as much as the equipment.
For a full *ideal* loom you will require four (4) mains cables five (5) BNC clock cables six (6) AES or RCA digital interconnects plus one pair of analogue interconnects (2) so 17 in total!
Luckily most of us only require five!
There is some revamping of the dcs range due in the not to distant future as well as the dropping of some products like the network streaming bridge.
Sorry cable lengths for digital, my 75Ohm BNC clocks cables are 0.8 and 0.6m long for the master clock to each of the Mutec's have tried 1m identical versions and personally can hear zero difference, however my own system using some rather nifty data 're alignment methods' in the I2s stream. The clock cables are instantly noticeable if you change them, again personal preference as to whether each person feels the outlay is justified.
As with everything in audio each circumstances are different.
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optical
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Post by optical on Jun 11, 2021 9:18:56 GMT
Thanks for the feedback there misterc.
The rabbit-hole of digital is both daunting and intriguing to a similar degree. Not least due to the potential outlay required to 'cover all bases'. BUT, if you are shopping in these departments so to speak, then why the heck not.
From what you are saying there are gains to be had if the rest of your system can support these expensive tweaks but for the most part the results are incremental. It's still those bang for buck leaps in performance we all crave from low to high end. Although it's less 'important' at the top end of the spectrum in regards to cost, although that's not to suggest your high end customers lack perspective, I'm sure they still appreciate good value, it's just they have the means to explore the more ultimate end of equipment.
If I had the funds available that's exactly what I'd be doing too so can't knock them for that!
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Post by misterc on Jun 11, 2021 9:44:09 GMT
Hi Optical
Digital I find is far easier tha analogue!, especially with cart/arm combinations so many to chose from, however I find that keeping a presepctive on your current equipment level and what you are looking to achieve given your circumstances are a great grounding point.
You can make a good digital cable for around £75 to £100 that could out perform a lot of well repected brands offerings up to £500, similarly you could have an opposing effect if incorrect impleimented.
With anaogue reently I have beeen trying a new arm/cart set up on our Delphi MK VI gen II a Thales simplicity MK II and a nice jap ushi cartridge quite something, never really liked the SME sound found it to mechanical this arms are quite something and very comparable to sme v current pricing.
Anyway happy to assist where I can
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Post by macca on Jun 11, 2021 13:12:45 GMT
Thanks for the feedback there misterc. The rabbit-hole of digital is both daunting and intriguing to a similar degree. Not least due to the potential outlay required to 'cover all bases'. BUT, if you are shopping in these departments so to speak, then why the heck not. From what you are saying there are gains to be had if the rest of your system can support these expensive tweaks but for the most part the results are incremental. It's still those bang for buck leaps in performance we all crave from low to high end. Although it's less 'important' at the top end of the spectrum in regards to cost, although that's not to suggest your high end customers lack perspective, I'm sure they still appreciate good value, it's just they have the means to explore the more ultimate end of equipment. If I had the funds available that's exactly what I'd be doing too so can't knock them for that! I have the funds but I don't go down the rabbit hole, why is that? Because there's nothing down there. Not knocking the people who do, or Mr C et al for selling it, that's not my concern.
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Post by optical on Jun 11, 2021 13:36:46 GMT
Thanks for the feedback there misterc. The rabbit-hole of digital is both daunting and intriguing to a similar degree. Not least due to the potential outlay required to 'cover all bases'. BUT, if you are shopping in these departments so to speak, then why the heck not. From what you are saying there are gains to be had if the rest of your system can support these expensive tweaks but for the most part the results are incremental. It's still those bang for buck leaps in performance we all crave from low to high end. Although it's less 'important' at the top end of the spectrum in regards to cost, although that's not to suggest your high end customers lack perspective, I'm sure they still appreciate good value, it's just they have the means to explore the more ultimate end of equipment. If I had the funds available that's exactly what I'd be doing too so can't knock them for that! I have the funds but I don't go down the rabbit hole, why is that? Because there's nothing down there. Not knocking the people who do, or Mr C et al for selling it, that's not my concern. There is something very admirable about your concrete rigid stance on the subject Martin (I actually mean that). The potential for improvement intrigues me. To be fair I think the conversation (although not so obviously perhaps) was shifted toward the digital domain in general, so referring to clocks/jitter etc, which is a universally regarded and recognised factor in the reproduction quality of digital. Regarding cables that do the simple job of carrying digital signal, a 'cheap' perfectly well designed cable may well be adequate in most systems so I agree with you there (if you meant cables specifically). Where logic indicates there should be a potential audible improvement to me, is the speed/accuracy of re-clocking or piecing together of the datastream. Whether or not a cable can play much part in this I really cannot decide. BUT in summery I think there is a lot more to be improved/gained in the digital domain from various methods than you seem to give credit for. That's fine, it's good to have a difference of opinion.
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Post by macca on Jun 11, 2021 15:26:26 GMT
well there's opinion and then there is what is possible in physical reality. If I told you I could jump over my house you'd say no you can't. Would that be just your opinion or a statement of fact?
With regard to multiple clocks and re-clocking it makes no sense. It doesn't matter how many times you re-clock, only the last clock in the chain will matter.
With regards to jitter this was never an audible problem even with the very first CD players. When stand-alone DACs again became a thing back with the introduction of streaming, marketing departments latched onto it as a technical term that most punters would not understand but which could be used as a USP to differentiate their product from the mass of similar/identical products.
Magazine reviewers - who mostly know absolutely nothing about how hi-fi equipment actually works and have no interest in learning - simply repeated the marketing spiel and gave it credibility.
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Post by misterc on Jun 11, 2021 15:50:29 GMT
Martin It is good to have a postive reinforcement of your beliefs which is why is good to have counter balances here on AA. My 2p worth I do firmly and rigously test all devices (both electrically and hearing wise) and come to my own conlusions regarding any postive or negative differenices regarded SQ
Without question I could not deliver the performance I have wihout specific mains/cabling and clocking solutions and to discern between with and without such pieces does not require any bat eared human or some wonder writing sitting in a glass tower expelling the virtues of roduct 'x' and 'y'. So I appreciate the counter balance you bring here.
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Post by Bigman80 on Jun 11, 2021 17:34:17 GMT
Martin It is good to have a postive reinforcement of your beliefs which is why is good to have counter balances here on AA. My 2p worth I do firmly and rigously test all devices (both electrically and hearing wise) and come to my own conlusions regarding any postive or negative differenices regarded SQ
Without question I could not deliver the performance I have wihout specific mains/cabling and clocking solutions and to discern between with and without such pieces does not require any bat eared human or some wonder writing sitting in a glass tower expelling the virtues of roduct 'x' and 'y'. So I appreciate the counter balance you bring here. Ok T, If a DAC has a clock and it's, say a Accusilicon AS318B 100Mhz Femto Clock, which is pretty darn good by all accounts, why does It then "need" (in the opinion of some digital enthusiasts) a reclocker to get the best out of it? Is that clock not up to it? Does having two clocks Master clock double up the level of performance? What's the craic? Serious question as I don't know the hows and whys all this Sh#t ends up plugged into the back of devices that should be doing the job correctly on the first place. Oh, answers in layman's terms please 😉
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Post by misterc on Jun 11, 2021 18:41:32 GMT
A good question Oli
The answer is transmission line disturbances:
A transmission line begins at the start of the ciruit and ends at the destination point and encompasses EVERY pathway inbetween, whether passive components, board connectors (coax small format signal lines) FPGA's opto isolators board strip lines (even with FR4 with Megtron 6 dielectric) have an effect on the signals. In fact now with the high data transfer rates for Pam 4 (or even PAM 8) and upwards. Coax is used as a circuit pathways simply as the max board speeds are now around 29Gb's with coax it can go as high as 40Gb/s but this is still mno where near what is required for the 800 formats currently being developed.
We call this signal integrity and the goal is presevation of such as much as humanly possibly given the design critera imho.
You could have say the best clock in the world at the heart of your digital audio dac, yet it will never produce its theorectical potential due to many outside elements distrubing the circuits.
This is all about design ability V's finial production costs and end user pricing.
The clock signal starts to be affected as soon as it leaves the output pin on the TXCO or OXCO on the board, it has to cope with 'aggressor' agents such as power rail noise, impedance pathway mistmatches, incorrect grouding veers on the circuit board, rfi ingress, regulator switching, dc<>dc switching, digital logic noise, outside rf ingress and much moe issues.
Also (you can charactorise this as phase/jitter noise) problems other often over looked issues are ISI (inter symbol interferance) where bad coding is responsable for piss poor tx/rx eye patterns and the use of ingenious PLL filtration is employed to open up the eye pattern via pc code.
The impact of power rail noise on clock jitter cannot be over stated, and with high speed data there are a different set of rules for this as opposed to say a fixed frequency from a OXCO (audio clock) with is typically a guassian response when viewed via histogram.
Although the sympthoms are different with regard to various data speed issues the end results are pretty much the same resulting in restricted bandwidth, more jitter and bad data corruption at the rx end.
Now you can have an ultra low phase noise clock say 13fs @ 1hz which is pretty special you are getting into 'time nut' territory where these guys fixiate to measuring time to Jiffy's or below this is the amount of time light takes to travel one fermi (about the size of a nucleon) in a vacuum. Now they are even units smaller than this!
My point is the equipment required for this has to be kept ultra stable in temprature controlled enviroments etc, and the slightest knats fart will throw off the reading by a catiscrismic amount.
Back to audio, jitter comes in many forms and has effects way beyong 44.1Khz
My own scope has a time accuracy of 60fs which is pretty special, though I do use a lower phase noise clock to improve even on this.
Jitter forms in no particular order
Determinstic Jitter, Bi-modal jitter, Shot noise, ground bounce, inter symbol interferance, inpedance mismatching, lossy inerconnects (this is not just cabling lol)
Some great but tech heavy reading here:
This video is pretty basic but gives you a grounding into understanding why jitter is important for many applications and why it can be so important.
When we are designing equipment we have the ability to 'de embed' all of the components in the circuit pathway we are looking at, which means we can individually measure each section of the pathway and model it.
So if we come across a bad piece we can take a virtual model and then in the scope, present the recreated signal with a different set of filters to simulate the ideal pathway, this helps us with improving the design for the next spin.
Your question of why is it just not right straight away Oli? Well I refer my Learn'd colleague to the answer I gave eariler simply COST
A re-clocking latch (that is takes in the incoming audio data signal and in laymans terms cleans up the signal the represents back to the recieve destination still has to travel through the remaining transmission line (which is from the exit point on the re-clocker, to the point in the dac where the sound leaves the converter as an analogue wave form).
So it will always be an imperfect transmission line except the re-clocker is correcting a lot of the artifacts that are caused by the transmission line but not all, tis is why some of use a pair of them in series like a double bubble, granted not twice the effect but still a significant improvement over a signal one imho.
You can further improve this by connecting a reference master clock to the re-clocking device where the master timing signal comes from a reference 10Mhz word clock (generated by a ultra high quality clock), rather than the re-clocker extracting the word clock portion from the incoming data stream to 'time' the other two components of the audio data stream which are the actual audio data and bit clock.
Jitter is very simple, it is the calculated time the signal should arrive at piont 'A' aganist the acutal arrival in real time, jitter is simply the difference betwee the two. how important is it? these days rather so with high speed digital communications.
To put this into perspective the manufacturing cost of a ultra low, ultra stable refernce quality double oven OXCO costs more than many of the dacs that are currently flavor of the month in certain on line publications and to obtain that cost you need to purchase MOQ of 200+ this is just for the oscillator and nothing else!
Tomorrow I will figure out some experiments to illustrate this for you in real world terms.
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Post by macca on Jun 12, 2021 9:36:28 GMT
Is jitter really worth worrying about? here's the jitter distortion measured on a DAC you can buy new for under £150 Can you hear distortion 110db below signal level? To put that in perspective it is like hearing someone shouting to you from 500 kilometres away. By contrast a good turntable will have about 1000 times more jitter, it will be easily audible. 'But my turntable sounds fantastic!' Exactly.
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Post by misterc on Jun 12, 2021 9:41:57 GMT
At this point I have written this three Fooking times and getting seriously pissed off now This morning, I feel clarification would help you chaps in the understanding of how digital audio data is actually 'moved' if you like and how it is made up and used within an audio system. Audio data is sent via a serial data interface know as Inter IC Sound (I2s) It is a synchronous bus based on three wires which are used to pass multiple channels of audio data over a single line for use in connecting digital audio devices together. Philips developed this format back in the dark ages of 1986! with a revision in 1996. I2s formatThis can be broken down to the following channels: left Justified Right Justified TDM (Time Domain Multiplexed) Simplified explanation of the Is2 format not to technical!So you have three individual data streams contained within the PCM signal itself: Serial clock Word Select This is used to perform the data syncing for the serial data line (hence why this is important!) it can be make or break for quality audio this is generated by extracting the incoming data and by using the internal TXCO etc and PLL (phase lock loop circuit) the word clock can be refined to give improved serial data alignment. Serial data this has two options MSB and LSB (most significant bit and least significant bit) Getting back to clocks in general accepted wisdom is that the the straighter the 'leading edge' the wave form the more desirable the clock will be, this can measured with a rise time feature on most scopes or you can use curses or old fashioned algebra!) Rise timeNow you can have an all singing and dancing femto second oscillator (clock) side bar fact for you In one femtosecond, light travels just 300 nanometers — about the size of the biggest particle that can pass through a HEPA filter, and just slightly larger than the smallest bacteria!
However the clock is just one part of the circuit this is responsible for generating that all important word clock timing signal and as discussed in the previous post many factors effect this performance! So now we have a super fast ultra straight leading edge that our clock is providing 'Cracking Cheese Gromit' moment must be giving me sublime SQ Well not so fast Captain timing, you see there are by products of having a almost vertical straight edge to the leading portion of the wave form yes indeed harmonic content also increases exponentially, Oh what does that mean? Example for you, today's super dac chips with eight (8) individual dac inside each chip (impressive eh?) both Sabre and AKM has gone down this route these have totally different requirements for say the good old TI PCM 63K where you bog stand 16.394Mhz was all you required to give you that juicy red book standard of 44.1Khz. Or that mind blowing figure of 18.432Mhz for the studio 48Khz mode.
These days clocks are generally much higher in frequency for this multi dac chips around 100Mhz (100 Million hertz) they need to be this frequency to enable the circuitry they use to generate the bigger sampling frequencies up to 768Khz, they do this by use of frequencies dividers and multiplexers so only one clock frequency is required.
However having a femto second clock @ 100Mhz does bring other challenges to the equation such as unwanted spurious noise sitting on both clock and power lines recently I have experience with this on a customer project, his dac (given top billing and best ever on a well known measurement internet review site at the point) problem was it was a hard as nails made Naim sound like Harbeth's yes it was very detailed open and powerful but seriously brittle.
Measuring the unit (audio wise on R&S UPV) all the usual audio traits were very good indeed, THD/IMD/SINAD etc. What's the issue here then?
Taking a closer look with a spectrum analyzer and using rf sniffer probes in conjunction with a specially designed RF current probe revealed spurious RF content reaching to around 2.5Ghz (2.5 Billion Hertz) sitting on the analogue output stage! This turned out to be emanating for the Crytek uber clock which was generating over 25 first order harmonic spikes.
So what I here you cry, our hearing is limited to around 15-16Khz for us bunch on here now, so with zero possibility of hearing these frequencies (if you could I would be really worried you have alien DNA at the very least )
Back to reality, however these frequencies can and do effect other components within the audio box,really? The spurious noise has all kinds of side effects on other electronics components inside your audio equipment which in turn causes SQ issues.
Below are image of before and after I rectified the RF noise within this particular dac, part of the remedy was to remove the Crystek clock and substitute a 'lesser clock' in specs but with a more sympathetic leading edge plus some internal RF work on certain parts of the power supply and output stage. Also this particular product would have never passed CE certification in a million years yet it was given the usual smoke up its ass badge
Result was vastly superior tonal quality, lower noise floor, zero glass shard type sound piecing your tympanic membrane sound and much much more long term listen ability plus a very happy customer.
None of this shows up on a 20hz-20Khz audio analyzer, unless you have done a BEFORE and after work report then the differences can be seen imho. This is a spectral plot from 10Khz to 2Ghz, the best audio analyzers top out @ 400Khz I believe with limited RBW (resolution band width) for FFT (just over 1/500th of one of the horizontal divisions on the above image)
So we have the ability to look at the Inter IC Sound serial bus (I2s) in its raw format and view the data packets as Hex/Binary/decimal and dB decoding via our digital section of the scope while also looking at the eye pattern and FFT (Fast Fourier Transforms of the signal.
In essence we can see all of the data and its flaws in wide open detail from start to finish, its a great ability to have and to analyzer how each company goes about its methodology of making ' great audio'
Hope that clarifies the subject some more for you.
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Post by antonio on Nov 9, 2021 2:32:22 GMT
Did you ever purchase a new digital cable and if so what? Did wonder if you went with the AE ones
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Post by optical on Nov 9, 2021 8:06:54 GMT
Hi Antonio, thanks for the follow up. Does this answer your question . . . ?? Maybe, maybe not! Haha. I took some advice and ended up making my own too . . . . Front to back is: 5N OCC 50cm 75ohm cable with pure copper RCA's 6N OCC (silver tinned) 75ohm cable with 1 pure copper and 1 BNC termination 6N OCC (silver tinned) 75ohm cable with pure copper RCA's 5N OCC 75cm 75ohm cable with pure copper RCA's - purchased from Oli QED Reference digital 40 (50cm) Canare 75ohm 1 RCA and 1 BNC connection (75cm) Why do I have so many cables? Well becasue I bought a bloody Mutec and have two DAC's to run off it . . . . I haven't even got started comparing AES cables yet! haha. Utter madness I know, no need to tell me . . . .
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Post by brucew268 on Nov 9, 2021 10:36:37 GMT
I recall in the early 90's Chris Sommovigo designed coax cables based on true 75 OHM and 1.37M finding that other impedance or other lengths tended toward reflections in SPDIF. I don't recall if that math was backed up by measurements and listening, but people were suggesting to avoid short lengths of coax like 0.5M. Perhaps Tony misterc knows something about this, measurement hound that he is?
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Post by optical on Nov 9, 2021 10:54:00 GMT
I recall in the early 90's Chris Sommovigo designed coax cables based on true 75 OHM and 1.37M finding that other impedance or other lengths tended toward reflections in SPDIF. I don't recall if that math was backed up by measurements and listening, but people were suggesting to avoid short lengths of coax like 0.5M. Perhaps Tony misterc knows something about this, measurement hound that he is? Yes the consensus is/was that using toslink optical cable could create reflection if it was less than around 1.5 - or pretty much exactly what you said, and said better than I! I had always assumed with coax cable that the shorter the better (as long as there are no sharp bends collapsing the structure of the cable etc), however I have found that for some reason the cables around 75cm in length seem to outperform cables made of exactly the same material (including plugs) which are shorter. Weird. As you say there are probably some logical explanations for this kind of cable behavior . . . . . Or maybe there isn't . . . . but anyway, they do seem to sound different. In my systems coax always sounds better than Toslink, although theoretically Toslink does hold electronic isolation advantages . . . .
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Post by macca on Nov 9, 2021 11:03:44 GMT
To avoid reflections COAX sp/dif cable should be >= 1.5 metres.
It shouldn't matter with 'modern' DACs
There was never any evidence of audibility that I am aware of.
I did buy a 1.5 meter cable myself, just for peace of mind and because it wasn't any more expensive.
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Post by optical on Nov 9, 2021 11:17:30 GMT
To avoid reflections COAX sp/dif cable should be >= 1.5 metres. It shouldn't matter with 'modern' DACs There was never any evidence of audibility that I am aware of. I did buy a 1.5 meter cable myself, just for peace of mind and because it wasn't any more expensive. Yeah you're right, I had assumed it shouldn't affect COAX in the same way it does sp/dif (optical) cable, but it seems it could/does. Reducing 'inaudible' jitter really has made a difference using the Mutec, (or whatever else it's doing) so maybe reducing 'inaudible' reflections (by making all digital cables >1.5m, of which there are 3 going into and out of the Mutec!) could further improve the presentation. . . .
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Post by macca on Nov 9, 2021 12:04:12 GMT
I don't know what the Mutec does to make a difference, and I don't agree that it's been established that it does make any difference (although at this point I still accept that it might), but whatever the reason for the perceived improvement it isn't reduced jitter. That's a certainty.
Given that digital cables aren't expensive (or don't have to be) I don't see any reason for not getting one long enough to be able to be sure that any potential issue is just not a factor.
if you're not getting drop-outs or other glitches in the sound then the cable is 100%, regardless of length, make, price, what plug it uses. There's no situation possible where it will work fine but 2nd violin sounds a bit screechy compared to how it sounds through some other digital cable. We might perceive that it does, but that's a different matter.
I swapped digital cable recently from Gotham to Mark Grant. Immediate impression - sound was brighter and livelier with the Mark Grant. Was it really different? Of course not. It's just how our perception works. If someone had secretly swapped the cables without me noticing, I would not have perceived any difference at all.
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optical
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Post by optical on Nov 9, 2021 12:26:05 GMT
I don't know what the Mutec does to make a difference, and I don't agree that it's been established that it does make any difference (although at this point I still accept that it might), but whatever the reason for the perceived improvement it isn't reduced jitter. That's a certainty. Given that digital cables aren't expensive (or don't have to be) I don't see any reason for not getting one long enough to be able to be sure that any potential issue is just not a factor. if you're not getting drop-outs or other glitches in the sound then the cable is 100%, regardless of length, make, price, what plug it uses. There's no situation possible where it will work fine but 2nd violin sounds a bit screechy compared to how it sounds through some other digital cable. We might perceive that it does, but that's a different matter. I swapped digital cable recently from Gotham to Mark Grant. Immediate impression - sound was brighter and livelier with the Mark Grant. Was it really different? Of course not. It's just how our perception works. If someone had secretly swapped the cables without me noticing, I would not have perceived any difference at all. As I've said before I do admire some perseverance, but I think there are enough examples of overwhelming audible evidence that something measuring exactly the same does not equate to it sounding the same, that is my current opinion. I get better and just more bass out of one cable compared to another. I agree electronically it should be the same, electrically it is, audibly it is not. Conductivity measurements (and indeed maybe jitter measurements) aren't necessarily giving the full story here. Again, just my current opinion. I know we're going round in circles again here but I'm happy to continue having the debate. I've been doing this for days, swapping one cable for another with zero other variables yields a bigger thump in the chest. You cannot 'perceive' this particular physical thump in the chest.
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