No.
Don't try telling the many people that are hearing differences due to power supplies in different areas, that they are all imagining it!
There are also numerous reports in Forums like Computer Audiophile of upmarket USB cables ,which invariably have improved separation between Vbus and the twisted pair D+ and D- leads, sounding better also. Even better are the USB cables that use separate power and data cable that only come together at the USB plugs.Better again, if you are using an external USB PSU, is to disconnect Vbus at the PC end of the USB cable.
Alex
Don't try telling the many people that are hearing differences due to power supplies in different areas, that they are all imagining it!
erin's case above needs no imagination to explain the differences - noise levels.
What requires a leap of faith too far for many (not myself I hasten to add
) is the purported existence of epi-information which gets carried along with the information in some digital copies but not all.
That's the type of problem that has come up before in these discussions, that is, unless someone recently has figured out what's going on.
You can have two "bit identical" discs and they can sound quite a bit different. In one case, it was found by viewing two different disks (same music file, different burners) through an electron microscope that there were actual visable differences in the burned pits of the disks themselves.
I mentioned this a couple of years ago (I believe).
In another case, a glass master and a disk made from that master were played for the members, and the difference was astounding. The glass master was "much" better, but wouldn't you know it...they were bit identical when compared.
Among the people in our club that listened to this, were several Software Engineers (most from a giant Software Company in Redmond) and they were certainly scratching their heads over this.
AFAIK, there hasn't been any real explanation or comprehensive theory that explains it.
Best Regards,
TerryO
It seems to me that there is a difference in kind between the examples you gave where there's a physical medium involved and what Alex is keen on talking about. As you noted the pits can be in slightly different places between the master and subsequent copies. But when its solely information - as when a file is sent over the internet - these kinds of explanations are ruled out. There's nothing physical being transferred as far as anyone's aware. The question then becomes "In what sense is the file I received by download the same file as that that was sent?".
Richard
We need to remember that I am not alone here, as the previously attrached link will show.( I could also attach numerous other confirming reports/links from around the world too.)
I did supply the .wav files that were the basis of M.C.'s thread though.
Alex
http://www.hificritic.com/forum/default.aspx?g=posts&t=731
Yeah not in any way disputed by me. You've brought the issue to my attention but its not just your listening reports that find the same effect.
Most recent soundcards do not resample. However, the general purpose audio stack in most OSes resamples since it has to be able to mix several streams. But that is a software issue, not that of the card itself.
Wow I never would have even thought to try different power supplies on routers to improve the sound on my squeezebox.
I can see this, it makes sense to me that on play back with mechanical devices may introduce jitter.
The 'problem' that i see with all of this that quite a bit of the differences being shown are purely subjective using the all too common descriptor....'better'. Looking from the outside as a person who is currently here to actually build a high end digital audio server, the things that concern me the most are measured results. I know what's actually audible so i can sift through the data to make informed decisions as to what products to use and how to properly impliment them. If i can avoid overspending based on subjective claims, i'm all for it.
An all-in-one PC type device is obviously the simplest to assemble and operate/integrate while a modular system with isolated power supplies for each component of the chain offers significant signal chain advantages. BUT.....are the advantages actually audibly recognizable? I'm 45yrs old, have worked in the music industry for most of my adult life and truthfully can't here above 16khz. My room is treated and my playback gear isn't esoteric, but it isn't bargain box store stuff either. Resolution IMO is very high and if there's signifcant noise in the digital chain that the system DAC is going to reproduce as some type of noise, chances are i'm going to hear it. But does a DAC actually do that? If it's only concern is the digital stream, what happens to the noise?
Jitter and clock speed seem far more impactful than power supply noise....to this novice anyways.......
An all-in-one PC type device is obviously the simplest to assemble and operate/integrate while a modular system with isolated power supplies for each component of the chain offers significant signal chain advantages. BUT.....are the advantages actually audibly recognizable? I'm 45yrs old, have worked in the music industry for most of my adult life and truthfully can't here above 16khz. My room is treated and my playback gear isn't esoteric, but it isn't bargain box store stuff either. Resolution IMO is very high and if there's signifcant noise in the digital chain that the system DAC is going to reproduce as some type of noise, chances are i'm going to hear it. But does a DAC actually do that? If it's only concern is the digital stream, what happens to the noise?
Jitter and clock speed seem far more impactful than power supply noise....to this novice anyways.......
The reason I posted these examples is to, hopefully, demonstrate that the usual bit check methods aren't showing any differences and yet the sound can be different. This has been a stumbling block in prior threads, when the orthodox view, or the prevailing conventional wisdom, dictates that if they are bit identical, they will sound identical. Perhaps they should, but there have been too many examples of this not being the case, that it can't (or shouldn't) be ignored.
Too often, people have stopped right there and just stated that it's not possible, or worse, that a bunch of charlatans are seeking to undermine established truth with some sort of mystic nonsense.
The use of precision power supplies, isolation and shielding, etc., are well known factors in electrical engineering and why they wouldn't be applicable in the use of digital technology is very much a mystery to me.
I'm aware that this doesn't answer your question, but is meant to point out to those that are following this thread and aren't aware of the previous discussions, that not all is well in Denmark.
Best Regards,
TerryO
I agree with all of this. I started using usb power with the Gamma 2 and then went with a wallwart and then the Sigma 11. Audible difference every time. Good usb cables with real copper in them (not the 110 ga. Chinese stuff that looks like copper) makes a difference too.
Maybe we need an OS project for a really hi-end, external power supply for computers?
How was the playback achieved on the glass master vs. the disk?
Definitely there are physical differences between different disks of the same music. You can also have the pits corresponding to the same positions so different between two disks that a reader will consistently read a raw "0" value instead of a raw "1" value. But if there are few enough errors, the output of the Reed-Solomon decoder will produce the same data bits, and then we say that they are bit identical (in terms of the output or actual data).
How does the storage mechanism have anything to do with the D/A conversion? The D/A is where jitter occurs. Wonky clock signal or power supply or just a bad implementation, can introduce some jitter on the D/A. Audibility of this jitter, depending on how bad it is, is up for discussion.
Maybe this isn't very interesting from a DIYer point of view, but depending on your expectations, you can definitely buy ATX computer SMPS with very clean outputs. Whether or not this actually makes a difference is a different story. A system with low PSRR with a noisy power supply is not good, that's for sure. Cleaner power can mean (very slightly) better control of the motor on the optical drive, or on any of the digital logic devices in a computer. In the least there will be smaller probability of system instability, BSOD, and so on. If you're really paranoid, get a system with ECC RAM? But how often do you think that bits get flipped while being shuffled around in a computer? And then in those circumstances, that they get past error-control coding, if it's applied to the situation in question? Are your photographs changing over time as you copy them from one hard drive to another?
Here's a top-end unit at about $280, which of course has way more wattage than almost anybody needs.
Antec High Current Pro HCP-1200 1200W Review - Page 7/8 | techPowerUp
Antec High Current Pro 1200W Review
Even about $40-45 gets you something pretty well behaved (though check the transient response page).
Corsair Builder CX430 V2 430 W Review - Page 7/8 | techPowerUp
Corsair CX430 V2 430W Review
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As this is directed to me, I'll just say that they were played on a Sony 777ES deck. The differences were far from subtle to say the least.
As all this has been covered in previous threads, it doesn't make much sense to start all over again.
Best Regards,
TerryO
Hi Richard, what seems strange about this, is that CAT5 is a balanced transmission line. So common mode noise should not be the issue here? The cable I use running to the squeezebox does not have shielding so that should eliminate ground loops. I presume the router would use transformer isolated inputs and outputs?
So how is the noisy power supply affecting the sound?
You will remember that I said I heard the sound become more dynamic when using the 4A power supply. I hypothesise that the higher current capability of the power supply allows the chips on the router to switch with a greater slew rate than the lower current power supply, and the noise affects the clocks in the router.
The thing is that I really enjoyed the more dynamic sound. If I could achieve the same dynamic sound with the clairity and grain free nature of the smaller supply I would be very happy.
I use an LC mains filter on my Squeezebox, and all my HiFi equipment, as well as ferrite clamps on my power cables. I use ferrite clamps on the router power supply, but no mains filter on it.
Easy to clear up this one - power supplies with output noise in the realm of 10s to 100s of mV work in digital circuits (by which I mean the average PC, not an audio system). Given they give the desired results, why try to gild the lily? A manufacturer building PCs with lower noise supplies is over engineering and will eventually go out of business. That is unless his target market is audiophiles
Having an ultra-low noise PSU is fairly irrelevant when the circuits being powered (CPU, logic, memory) generate such huge self-noise - this is not generally the case in pure analog circuitry.As for isolation and shielding - its applied in a PC to the extent to meet the relevant EMC regulations I believe.
Easy to clear up this one - power supplies with output noise in the realm of 10s to 100s of mV work in digital circuits (by which I mean the average PC, not an audio system). Given they give the desired results, why try to gild the lily? A manufacturer building PCs with lower noise supplies is over engineering and will eventually go out of business. That is unless his target market is audiophiles
As for isolation and shielding - its applied in a PC to the extent to meet the relevant EMC regulations I believe.
I certainly agree, but there are those that feel that if the factory didn't bother with something, then it must not be an issue, and in many cases they're right...just not in this one.
Best Regards,
Terry
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Balanced transmission lines carry common mode noise for sure. The reason for balanced is to allow the receiver circuitry to reject common mode noise - but once it's present it gets into the system (grounds) even if not in the signal being processed. Ethernet interfaces often contain chokes to reject this kind of noise, but they're not very wide-band AFAIK.
The ground loops at issue here aren't the normal LF ones - those do require a DC path which is often the screen. Rather here they're RF ground loops, so the signal passes through the inter-winding capacitance of the ethernet isolation transformers and the power supply transformers in wall-warts. My hypothesis for how this affects the sound is that the RF signal eventually gets into the analog circuitry and intermodulates with the audio. The primary route of entry is opamp input stages (one reason why opamps have gotten such bad rap in audiophile circles).
What I think happens with the 4A supply is its generating more RF (higher output currents mean bigger switching currents). This translates to more noise in your analog circuits and I think this results in greater sibilance. My guess is the result of this sibilance is emphasized transients (leading edges). That sibilance also brings grain and is more fatiguing to listen to over the longer term.
What DAC are you using after your squeezebox?
Details of your LC mains filter? If it contains Y caps it might be doing more harm than good
Its not an issue if the computer's used in a purely digital system (as I believe the majority of them are - high quality audio is very much a minority sport).
, and in many cases they're right...just not in this one.
In this case people are hoping that COTS PCs will be (or can be made) specialist enough for audiophile applications. I have my severe doubts which is one reason I'm pursuing an alternative avenue for digital sound systems. I wish all PC-based audiophiles the best of luck because I think they'll need it
So you dont think there is any chance of faster slew rates when using the higher current supply? Or is there the possibility that the 1A supply is slightly inadequate - slowing the slew rates?
HiFi DIY TDA1541 NOS with valve output stage.
TDA1541 DAC - $265.00 : hifidiy.net (much, much better sound than the analogmetric kit) Actually, I should elaborate, in comparison to the analogmetric kit, the HF sounds more extended and "airy". The bass has much more clarity and tonality, and goes deeper. The midrange has more "naturalness"
Using Polycarbonate 220nf caps on the decoupling pins.
I have also done the DEM reclocking on it. And about to install SMD cornell dubilier caps (as recommended by ecdesigns) under the TDA1541 (when they arrive) - which I have already tried on the analogmetric DAC with good results.
Details of your LC mains filter? If it contains Y caps it might be doing more harm than good
Yes it does use Y caps. Why do you say more harm than good? To my ears, this filter does greatly improve the sound, but I may try the system without it, just to double check
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