DIY hifi source

[marce]

The original image was derived from a .ts file saved on HDD. The 2nd image was derived from the .ts file after it was copied to a Corsair Voyager GT USB 2,0 memory stick powered by a very low noise +5V linear PSU. Both the + and - supply leads (red and black) were disconnected at the USB-A plug at the PC end and a 220 ohm resistor fitted across the + and - pins of the plug . This meant that there was no earth loop due to the screen of the USB memory being connected internally to the black 0Volts lead.

And were both files identical bitwise, if so they were exactly the same.
Ground loops and USB, what difference would that make, most digital layout and signal transfer involves as many ground connections as possible, if you were feading an analogue stage then isolation is best but for digital only transfer it dosn't matter.

[sandyK]

Marce
MANY C.A. members will tell you that even the type and construction of a USB cable results in audible differences, although according to present theory that shouldn't happen. The better cables usually have greater separation between D+ and D- and the noisy SMPS +5V Vbus line.Many people are getting vastly improved SQ from their DACs etc.by using PSUs such as The iFi iUSB Power Supply
The iFi iUSB Power Supply - Neat Tweak & Upgrade for USB DAC
Note the earth lift provision in the photo posted in the thread.
There are quite a few other products available as well , such as the highly regarded SOtM USB PCI-E low noise +5V power supply which is capable of having it's highly filtered +5V switched off for DACs using their own external PSUs.

[qusp]

Originally Posted by sandyK

Jeremy
I did NOT say anything about images coming from the same disc.
The original image was derived from a .ts file saved on HDD. The 2nd image was derived from the .ts file after it was copied to a Corsair Voyager GT USB 2,0 memory stick powered by a very low noise +5V linear PSU. Both the + and - supply leads (red and black) were disconnected at the USB-A plug at the PC end and a 220 ohm resistor fitted across the + and - pins of the plug . This meant that there was no earth loop due to the screen of the USB memory being connected internally to the black 0Volts lead.

Did you see the message that I sent you ?
Alex

you missed the point, when you have a file on a disc, whether it be HD or SSD, its not all stored in a contiguous physical chunk of data, particularly with SSD. Enterprise level SSD (which has trickled down into quality consumer level) stores the data across multiple memory addressees and using wear leveling so that it spreads the wear of write and rewrite cycles evenly, it will be constantly taking from different areas in the memory. so if it sounds different from different sectors of a disc, then if I played a 1khz tone, it wouldnt be able to hold a tone, which is ridiculous.

only just saw your message now, will reply tomorrow

[Scott6113]

As fun as all this is, it would come to a screeching halt the moment anyone throws down a three word gauntlet:
Blind listening test.
In one corner the best Cookie Gold CD.
In the other, the cheapest available generic CDR media with the info from that CD after being sent from Marcie's to Sy's to Powerpan's to gk7's mailbox and whoever else wants in, and let them copy it back and forth to and fro any and all lossless formats that strikes their fancy. We can make it go around the world a few times. Maybe the Van Allen belt will come into play. Anyone live near Leh Ladakh? That should do something.

Finally, our tired, world-weary bits would get checked in their final resting place by a three person, bi-partisan panel for errors, finding none, it and the virgin original would go in identical CD players good enough to read them with practically no errors wired to the same amp and speakers, as unforgiving as possible. Gk7 rigs an A-B switch. Leaves the room leaving no hint. Enter all.

Know who the winner would be? It will be ...


Wait for it...


Drum Roll.............................................. ............

[powerpan]

Originally Posted by gk7

So when I buy a high resolution audio file the sound quality will be
completely destroyed once I have it downloaded, right ?

Imagine it has to pass miles and miles of cable, routers switches ...
If there is a proxy, even worse, most of them don´t have a real time OS...

It might have the same checksum but this means nothing... the same
way as 2 + 2 = 5 for large values of 2, right ?

Sorry for the sarcasm, but such irrational claims provoke it.

@SY I think we should rather go for the drink I owe you, than wasting time
with this. ;-)

first of all, please make things clear, network playback means play files in local network store in NAS, local playback means play files in USB disk locally.

download will have bit perfect by tcp/ip protocol.

[qusp]

I see a double standard arising....

[DF96]

One of the things I love/hate about DIYaudio forum is the ease with which professional audio people, including manufacturers, can be provoked into proudly exposing their astonishing ignorance about the technology which provides their living! Even funnier/sadder, their fans sometimes chip in and agree with them!

When I was young I assumed that people who made and sold things were smarter than me. Then I got a job in industry and realised that I too could work at a 'world class' level with bright colleagues; I was the equal of others. Now I find that, as an audio amateur, I seem to know more than some of the professionals.

As I said, same bits plus same timing means same sound. The bits are guaranteed by modern IT systems (apart from random cosmic rays!!). The timing ought to be guaranteed by any serious audio system - we certainly don't want our digital audio sample timing to be reliant on variable things like interrupt latency in a non real-time system like a Microsoft OS. Where the bits came from is completely irrelevant. Anyone who thinks otherwise is just ignorant and/or gullible.

[gk7]

Originally Posted by powerpan

... will have bit perfect by tcp/ip protocol.

And your local network uses what ? Token Ring ? (If you still can remember that one...)

But for your ultra high demands probably Myrinet would be barely sufficient.

[powerpan]

Originally Posted by DF96

One of the things I love/hate about DIYaudio forum is the ease with which professional audio people, including manufacturers, can be provoked into proudly exposing their astonishing ignorance about the technology which provides their living! Even funnier/sadder, their fans sometimes chip in and agree with them!

When I was young I assumed that people who made and sold things were smarter than me. Then I got a job in industry and realised that I too could work at a 'world class' level with bright colleagues; I was the equal of others. Now I find that, as an audio amateur, I seem to know more than some of the professionals.

As I said, same bits plus same timing means same sound. The bits are guaranteed by modern IT systems (apart from random cosmic rays!!). The timing ought to be guaranteed by any serious audio system - we certainly don't want our digital audio sample timing to be reliant on variable things like interrupt latency in a non real-time system like a Microsoft OS. Where the bits came from is completely irrelevant. Anyone who thinks otherwise is just ignorant and/or gullible.

HIFI manufacturers sometimes do mislead people, studio equipments won't, we use professional studio equipments as the reference, that's all.

[Jim W]

I remember the old days when 1's were an honest five volt signal (more or less). How can anyone expect this newfangled 1.5V memory to sound good when it's not ones and zeros anymore, it's more like 1/3s and 0s???? TTL forever!

Sorry - this thread has degenerated into silliness so I figured I'd just pile more on.