As I have stated previously, there is nothing special on the jitterbug apart from a couple of common mode chokes, a few caps and resistor. Cost to manufacture overseas about $5 and that's being generous. Add to that a layout (that is supposed to reduce the high frequency noise from a computer or other digital source) that shows no isolation and looks to have plenty of capacitive coupling so the noise can just couple back in....
And you have a product that should grace the shelves of the Pound shops we have in the UK.
Yet question this product and the true believers jump on you with there usual childish comments and attitudes, telling you your views and comments are worthless.
And you have a product that should grace the shelves of the Pound shops we have in the UK.
Yet question this product and the true believers jump on you with there usual childish comments and attitudes, telling you your views and comments are worthless.
Not at all, just a dig at how all audio journalists use apple almost exclusively, although JA did roll out a PC for the ASUS Xonar review, which he sadly never completed.
Any quotes for me claiming the noise does not cause any jitter? I claimed all the time - low latency causes high CPU usage which in turn produces more noise.
The real-time kernel nonsense - again - no direct impact on jitter from the data delivery standpoint, it is not timed by the CPU at all.
Indirect impact of CPU-consumption noise patterns on the final jitter - perhaps, but unpredictable/unrepeatable and thus can hardly be recommended as a reliable solution.
Those were and are my arguments. Nothing has changed. I always disputed the low-latency part of your squeezebox patch (reducing the alsa buffer). The one which actually caused reported problems for the users - dropouts. I never commented on the other parts (wifi off, etc.) - they are outside of my interest.
No measurements because.... all other filters I have seen sold in the world of electronics have a spec sheet with details of what they filter and by how much, standard practice, so a device with no measurements sold exclusively to audiophiles has got to be suspect.
As to what happens in the digital world, are we talking noise, signal integrity all are measurable, the effect of both are known and what effects they can have in analogue/digital digital/analogue conversion...
This product like many others coming through are designed for a purpose, to extract money from the shucks...
we should get the manufacturer to send them this for testing Optically Isolated 7-Port USB Hub (HUB7i)
Bill your being silly now, its only $199 for a fully isolated USB hub, how can it be of any use for an audio system it does not:
1.cost enough
2. have an Audiophile designer to back it up.
3. Nowhere (and I do mean nowhere) can I find any reference to data packet noise.
4. It probably works as advertised.
It is for voltage isolation more than anything else, and like many products of a similar ilk makes no dubious claims about noise reduction or resonance control, probably because in the real world of electronics these things are understood and measured. If I recall correctly one of the group making a USB product have stated that they don't have the correct equipment for measuring what they are doing... sais it all.
I would like to know also how the jitterbug on another port has an effect....
The USB data lines are separate for each port driven from the transceiver and in all but the most horrendous cheapest device you could find, the 5V tends to be supplied uniquely for each USB connector, so that the total amount of current to each port can be controlled and also to prevent a dodgy device on one port taking down all the others.
1.cost enough
2. have an Audiophile designer to back it up.
3. Nowhere (and I do mean nowhere) can I find any reference to data packet noise.
4. It probably works as advertised.
It is for voltage isolation more than anything else, and like many products of a similar ilk makes no dubious claims about noise reduction or resonance control, probably because in the real world of electronics these things are understood and measured. If I recall correctly one of the group making a USB product have stated that they don't have the correct equipment for measuring what they are doing... sais it all.
I would like to know also how the jitterbug on another port has an effect....
The USB data lines are separate for each port driven from the transceiver and in all but the most horrendous cheapest device you could find, the 5V tends to be supplied uniquely for each USB connector, so that the total amount of current to each port can be controlled and also to prevent a dodgy device on one port taking down all the others.
@phofman
I told you a hundred times that we're not talking evenly distributed noise here.
The absolute load IMO does not really matter. It's the up and downs, the changes that matter much more.
Power fluctuations impact clocks, impact USB bits, impact everything...
Software and firmware impacts timing and processor load. These also translate into
power impact.
PCs work better with better power supplies. Audio Equipment works better with better supplies.
The SOTM PCI-USB Board is just a Hub with a better PS. That makes the difference. There's a simple logic behind all that. Even Marce might understand that.
How much all this impacts the audio performance is another chapter.
One thing I also learned from my PI mods. The better the PS and onboard power rails the less impact will have the SW tweaks.
The other thing I learned from my CubiTruck project. If turning most of the onboard features (WLAN/IR/BT/GPU/I2S/unsed USB/onboard Audio,...) via BIOS
off, not only the power consumption is greatly reduced - no , I also experience a much better (in audiophile terms) sound.
The expression "higher noise" doesn't say anything btw. Ever heard about the expression noise floor? There's all kind of stuff under the floor. This is not evenly distributed white noise, what we're/you're talking about.
There's wild stuff below the floor that can easy modulate into audio relevant parts of the chain.
Then there's all kind of other noise types. Measuring all these is an art on its own. Identifying parts of it that does this or that I'd consider a major challenge. Correlating these to audio performance is another challenge.
All this is all but trivial. And these complex situations change with every setup.
@marce - no more comments. I'm speachless about so much ignorance.
I told you a hundred times that we're not talking evenly distributed noise here.
The absolute load IMO does not really matter. It's the up and downs, the changes that matter much more.
Power fluctuations impact clocks, impact USB bits, impact everything...
Software and firmware impacts timing and processor load. These also translate into
power impact.
PCs work better with better power supplies. Audio Equipment works better with better supplies.
The SOTM PCI-USB Board is just a Hub with a better PS. That makes the difference. There's a simple logic behind all that. Even Marce might understand that.
How much all this impacts the audio performance is another chapter.
One thing I also learned from my PI mods. The better the PS and onboard power rails the less impact will have the SW tweaks.
The other thing I learned from my CubiTruck project. If turning most of the onboard features (WLAN/IR/BT/GPU/I2S/unsed USB/onboard Audio,...) via BIOS
off, not only the power consumption is greatly reduced - no , I also experience a much better (in audiophile terms) sound.
The expression "higher noise" doesn't say anything btw. Ever heard about the expression noise floor? There's all kind of stuff under the floor. This is not evenly distributed white noise, what we're/you're talking about.
There's wild stuff below the floor that can easy modulate into audio relevant parts of the chain.
Then there's all kind of other noise types. Measuring all these is an art on its own. Identifying parts of it that does this or that I'd consider a major challenge. Correlating these to audio performance is another challenge.
All this is all but trivial. And these complex situations change with every setup.
@marce - no more comments. I'm speachless about so much ignorance.
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Well given that a known tweak in USA is 'medical grade' power plugs, as they are less likely to just fall out the wall why not 'medical grade USB hub'. The association is made.
Note to our cousins from across the pond: Not having a dig, but when I lived in the windy city hoovering the house always had at least 3 plug loose incidents and a very warm cable afterwards.
UK plugs have their own problems, not least when you accidentally tread on them
Note to our cousins from across the pond: Not having a dig, but when I lived in the windy city hoovering the house always had at least 3 plug loose incidents and a very warm cable afterwards.
UK plugs have their own problems, not least when you accidentally tread on them
But USB is a packet interface. If a bit is impacted a retransmission will occur. Suspect wireshark can capture that if you put a tap in the feed.
The receiver should then remove all L1 and L2 nasties. That's its job. If it doesn't its not fit for purpose.
Interesting read:
Fundamentals of USB Audio | XMOS
After that explain "retransmission of packets in isochronous mode".
One thing you guys should keep in mind. Most reasonable USB links are usually not that bad. Data loss is not that common i'd say.
Noise has an impact on timing/jitter and makes it into the DAC. Pretty much all 4 lines and the shield carry this or that noise into the DAC.
I do consider drawings as presented on the iFi site kind of misleading. Because these really doesn't tell what these 5db noise reduction have to do with the analog audio.
This figure just shows that the filter has a certain effect under certain conditions.
For the bits - the digital part -5db (under lab conditions) might not even be relevant, if the receiver still can read the bits properly.
For the analog part for sure it can be of relevance, if that noise indirectly impacts other parts of the DAC.
I btw ran optical USB years back - battery powered on the receiver side.
It's been USB 1.1 only. I was quite happy with it.
It obviously didn't solve timing issues.
Edit: Most of this applies also to ethernet networks and streamers btw. Things are getting much more complex though.
Fundamentals of USB Audio | XMOS
After that explain "retransmission of packets in isochronous mode".
One thing you guys should keep in mind. Most reasonable USB links are usually not that bad. Data loss is not that common i'd say.
Noise has an impact on timing/jitter and makes it into the DAC. Pretty much all 4 lines and the shield carry this or that noise into the DAC.
I do consider drawings as presented on the iFi site kind of misleading. Because these really doesn't tell what these 5db noise reduction have to do with the analog audio.
This figure just shows that the filter has a certain effect under certain conditions.
For the bits - the digital part -5db (under lab conditions) might not even be relevant, if the receiver still can read the bits properly.
For the analog part for sure it can be of relevance, if that noise indirectly impacts other parts of the DAC.
I btw ran optical USB years back - battery powered on the receiver side.
It's been USB 1.1 only. I was quite happy with it.
It obviously didn't solve timing issues.
Edit: Most of this applies also to ethernet networks and streamers btw. Things are getting much more complex though.
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As to my ignorance, what ignorance, sorry just what I said earlier demean me yet you don't know what I do as a job, the projects I work on or where my speciality's lie....
Sorry but your the one showing ignorance, I do this for real (low noise layout etc.) in the big wide world, Ok I don't do consumer audio just mundane stuff like military/medical/aerospace so I do know what I am talking about. (I did a super fast ADC board for testing one of the sensors they have recently sent up into space as well as many other interesting projects where noise and accuracy are paramount.)
You are pretty much like the rest of the audiophile wanna be gurus, just call people ignorant or put them down because they don't follow your view or have opposing views.
So since you are so clever please inform me of where I am being ignorant, if you are going to call me then be more specific so I can answer because this sort of attitude really pi**es me off you are typical of those I mentioned in #81.
if you bother to read my earlier posts you may find something to educate yourself, I even put up an example layout to illustrate my points, not the work of an ignorant mind, but as usual ignored by the great and wonderful audio gurus, who just resort to name calling instead of rational discussion, not one has discussed what I have put just called me ignorant, you have to wonder who is the one who has so much ignorance....
Sorry but your the one showing ignorance, I do this for real (low noise layout etc.) in the big wide world, Ok I don't do consumer audio just mundane stuff like military/medical/aerospace so I do know what I am talking about. (I did a super fast ADC board for testing one of the sensors they have recently sent up into space as well as many other interesting projects where noise and accuracy are paramount.)
You are pretty much like the rest of the audiophile wanna be gurus, just call people ignorant or put them down because they don't follow your view or have opposing views.
So since you are so clever please inform me of where I am being ignorant, if you are going to call me then be more specific so I can answer because this sort of attitude really pi**es me off you are typical of those I mentioned in #81.
if you bother to read my earlier posts you may find something to educate yourself, I even put up an example layout to illustrate my points, not the work of an ignorant mind, but as usual ignored by the great and wonderful audio gurus, who just resort to name calling instead of rational discussion, not one has discussed what I have put just called me ignorant, you have to wonder who is the one who has so much ignorance....
In no way can you influence this by software in a controlled, consistent, and repeatable manner in a multiprocess OS. Every time the noise will be different, your playback process will be more or less randomly interrupted by other processes (also cranking the CPU to 100%), it will have a different impact. On the same HW, various HW is even more random.
I know there are projects detecting encryption keys just from PC noise. But these involve complicated processing of the noise.
If someone says the noise generated from sending samples every 5ms impacts the sound in a more pleasing manner than the noise generated from sending samples every 300ms, and especially if the change is "improved bass, smooth highs, etc..", well, I have yet to see a blind listening test that someone can even distinguish the two cases. Technically it does not make much sense.
But the truth is I have not seen many positive blind listening tests, with exactly zero from people claiming to hear technically unlikely differences.
Ah but you are forgetting we are dealing with super-humans, who can hear the digital noise and when it is removed by the likes of the jitterbug can tell the noise has gone even when measurements show no or very little difference.
But hey don't take anything I say as anything other than insane ramblings as I am; ignorant, a jerk, a fool, the owner of a sub standard audio set up, deaf, stupid and a few more choice insults that the wonderful golden eared brigade have called me recently
But hey don't take anything I say as anything other than insane ramblings as I am; ignorant, a jerk, a fool, the owner of a sub standard audio set up, deaf, stupid and a few more choice insults that the wonderful golden eared brigade have called me recently
Ah but you are forgetting we are dealing with super-humans, who can hear the digital noise and when it is removed by the likes of the jitterbug can tell the noise has gone even when measurements show no or very little difference.
But hey don't take anything I say as anything other than insane ramblings as I am; ignorant, a jerk, a fool, the owner of a sub standard audio set up, deaf, stupid and a few more choice insults that the wonderful golden eared brigade have called me recently
It doesn't matter what you do for a living, how good your ears/stereo are or how are sensitive your measuring equipment is.
To be able to partake in these discussions in any meaningful and audiophile-approved way you must have a wife who is not interested in audio and spends her life in the kitchen. They hear more accurately from there than even NASA could ever hope to measure.
@phofman
You just don't ( want to ) understand. You're an excellent IT expert. I really respect your knowledge in that area.
But that's about it. Sometimes it's good to widen the scope.
What I'm saying.. You don't get the the point.
It's not about 300ms or 5 ms.
It's about an unstable environment. There are numerous factors contributing to it. I havn't invented this. There are numerous IT sources on the net.
And yes. Even running a process on multiple CPUs instead of one can cause impact on my audio system.
Your blindtest statement doesn't say anything. It's nonsense.
I can setup a blindtest which proves you wrong - all the way.
You're invited and bring 10 of your buddies - if you ever manage to be in my area.
@marce - your latest post proves your limited horizon again.
You call yourself engineer??? God help.
"Ignorance" - Yep that's you. Similar to phofman. A different angle though.
The way you talk about "audiophiles" as a nuts species puts just yourself
into a corner. I'm a graduated telecommunications engineer myself. I'd also call
myself an "Audiophile" with engineering background.
I don't go into a store and measure the speakers before buying.
I buy on listening. A graph doesn't say much of how a speaker really sounds.
And that's what I also do with a DAC, amp, USB filter, cable, you name it.
However, I do run measurements at home to support tweaking this or that or to check
if my DIY projects work as expected.
Obviously a 100Mhz scope and a UCX won't tell you everything. Still it's
sufficient to figure out major flaws. That's good enough for me.
Beyond this, I trust my ears.
Enjoy.
You just don't ( want to ) understand. You're an excellent IT expert. I really respect your knowledge in that area.
But that's about it. Sometimes it's good to widen the scope.
What I'm saying.. You don't get the the point.
It's not about 300ms or 5 ms.
It's about an unstable environment. There are numerous factors contributing to it. I havn't invented this. There are numerous IT sources on the net.
And yes. Even running a process on multiple CPUs instead of one can cause impact on my audio system.
Your blindtest statement doesn't say anything. It's nonsense.
I can setup a blindtest which proves you wrong - all the way.
You're invited and bring 10 of your buddies - if you ever manage to be in my area.
@marce - your latest post proves your limited horizon again.
You call yourself engineer??? God help.
"Ignorance" - Yep that's you. Similar to phofman. A different angle though.
The way you talk about "audiophiles" as a nuts species puts just yourself
into a corner. I'm a graduated telecommunications engineer myself. I'd also call
myself an "Audiophile" with engineering background.
I don't go into a store and measure the speakers before buying.
I buy on listening. A graph doesn't say much of how a speaker really sounds.
And that's what I also do with a DAC, amp, USB filter, cable, you name it.
However, I do run measurements at home to support tweaking this or that or to check
if my DIY projects work as expected.
Obviously a 100Mhz scope and a UCX won't tell you everything. Still it's
sufficient to figure out major flaws. That's good enough for me.
Beyond this, I trust my ears.
Enjoy.
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I am an audiophile as well, just more grounded.
Again you go for insults, it shows what a petty minded person you are, at least I am in good company.
And why should it be god help, it seems the people I work with are happy with my work.
I could return the insult by saying call your self a telecommunications engineer, yet you sprout the rubbish you do.....
You show your ignorance by your direct insults.
So you don't read the specs on anything you buy including filters yet you claim to be a telecommunications engineer, me I listen but also do other research into things I am going to purchase.
Again you go for insults, it shows what a petty minded person you are, at least I am in good company.
And why should it be god help, it seems the people I work with are happy with my work.
I could return the insult by saying call your self a telecommunications engineer, yet you sprout the rubbish you do.....
You show your ignorance by your direct insults.
So you don't read the specs on anything you buy including filters yet you claim to be a telecommunications engineer, me I listen but also do other research into things I am going to purchase.
Actually, I practice and did study quite a bit of electronics too. I dare to say way more than you.
I understand all of that. You do not have to explain the mechanisms how the noise is created. But you have not answered my point - how do you consistently achieve the "audio niceness" of noice produced by various buffer sizes? You should know the answer, you intentionally changed them in your patch and claimed to improve the sound.
Me wrong? YOU are the one claiming the change improves the sound. You are to setup a blind test and prove your claim. Why did not you do it long time ago?
Trust me, you will not do anything in this direction. None of the golden ears has ever done any. And you won't either.
Get a better audio system then.....
Yep. First time I'm in line with you.
Look. This discussion I have here, I also have over at Audio Asylum.
In my opinion, I'll never be able to get the upstream (seen from the DAC) environment under control.
As long as DACs do not sufficiently isolate from upstream induced mess I'll have an issue.
Even galvanic I2S isolation and reclocking proved to be insufficient on certain devices.
And we're not talking about $100 DACs here.
When having these discussions, I usually conclude: Please let me know if there's a DAC
out there which is not affected by upstream induced mess.
I never received an answer to this.
Yep. Even if DACs are out here claiming FemtoSeconds jitter performance ( Yep - I do read specs and even read reviews) people wouldn't propose these.
It's not that easy. However. Before addressing a problem, people need to accept that it
exists. And the industry accepts a problem as soon as they have a solution to it.
That's one reason why there's been IMO extremely slow progress on that matter.
My SW tweaks and the basic logic behind it have been published a very long time ago.
I still do provide a number of friends with audio solutions.
I used to provide the Squeezebox Touch toolbox (Linux OS tweaks) which has been downloaded an applied numerous times.
If you have a problem with my experiences, why don't you visit Rune, Volumio, Moode....
and express your opinion.
You can also put Jplay, Roon, Fidelizer and even Foobar on the list for the Windows folks.
On OSX you continue with Amarra, Decibel....
Yep. All these guys are nuts.
However. All these serious computer audiophiles more or less follow a similar strategy for best audio quality from a computer.
Tweak HW and SW. No way around it.
The vast majority of them are suffering of DACs - at any price - that are not able to properly (in audiophile terms) cope with the upstream mess.
Enjoy.
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