[regal]

Notice I said the optical was arguably digital.   The main issue was the previous poster was claiming that ground isn't important because USB was a "digital" connection.  This is of course not correct.
 
Of course we could get into a fascinating philosophical discussion that all science is based on 1+1=2 and therefore every thing coms down to discrete (digital),  but thats another topic

Quote:

Regal I think you expressed your statement is not quite accurate. We live in an analog world, IOW any kind of transmission around you is done through analog mean be it through electron, photon or any other kind. Whether the transmission format is analog or digital is another matter. So USB signal is transmitted through analog mean, same as SPDIF, but these transmission formats are digital and they are piggybacked on analog means. To generalize: this rule applies to any kind of signal in use.
 
Now if only we lived in a world like TRON, we wouldn't need DAC process anymore.

 

[thuantran]

What you said is not precise again, which is annoying to me, being a computer science & engineering instructor in some university. Let's just say that transmission format can be digital or analog but the medium that they both go through is always analog. Digital transmission has higher resilience to analog distortion than analog transmission (that's why when digital signal reached a certain level of precision comparable or indistinguishable to analog signal, it's prefer over the latter), though if the distortion is severe enough you also have problem (SNR here). Lastly as digital signal is typically timed with a clock you might have jitter problem. Whether these digital signal errors are audible is another discussion. I didn't mean this as a personal attack BTW, I have OCD about things not right I think.
 
Back to the topic, where the hell is the OP? what's inside the little device and where the heck can we get it if it's premade?
 
 
Quote:

Notice I said the optical was arguably digital.   The main issue was the previous poster was claiming that ground isn't important because USB was a "digital" connection.  This is of course not correct.
 
Of course we could get into a fascinating philosophical discussion that all science is based on 1+1=2 and therefore every thing coms down to discrete (digital),  but thats another topic

 

 

[regal]

As an engineer I love the opportunity to refresh my learnings from a university instructor so no offense taken at all.   Since we are all waiting on the link,  I figure I could ask one more question.  I work with robots with digital outputs and inputs,  basically these are on/off transmissions that filip some relay or selenoid on or off.   Would you still consider this an analog signal physically as basically the most redimentary form of "digital" transmission?  We also have "analog" singals that control various devices with a zero to 10V signal.  It is sematics but as an engineer who minored in philosophy of science I have always always found that scientists can be grouped into those who believe in a  discrete physical world (ie Einstein) vs continuous physical world (quantum mechanics.)   
 
I've been working all night and feel free to just diregard my ramblings as that of a mad man,  sorry to derail this thread

 
Quote:

What you said is not precise again, which is annoying to me, being a computer science & engineering instructor in some university. Let's just say that transmission format can be digital or analog but the medium that they both go through is always analog. Digital transmission has higher resilience to analog distortion than analog transmission (that's why when digital signal reached a certain level of precision comparable or indistinguishable to analog signal, it's prefer over the latter), though if the distortion is severe enough you also have problem (SNR here). Lastly as digital signal is typically timed with a clock you might have jitter problem. Whether these digital signal errors are audible is another discussion. I didn't mean this as a personal attack BTW, I have OCD about things not right I think.
 
Back to the topic, where the hell is the OP? what's inside the little device and where the heck can we get it if it's premade?
 
 

 

 

[Mehve]

 
Quote:

As an engineer I love the opportunity to refresh my learnings from a university instructor so no offense taken at all.   Since we are all waiting on the link,  I figure I could ask one more question.  I work with robots with digital outputs and inputs,  basically these are on/off transmissions that filip some relay or selenoid on or off.   Would you still consider this an analog signal physically as basically the most redimentary form of "digital" transmission?  We also have "analog" singals that control various devices with a zero to 10V signal.  It is sematics but as an engineer who minored in philosophy of science I have always always found that scientists can be grouped into those who believe in a  discrete physical world (ie Einstein) vs continuous physical world (quantum mechanics.)   
 
I've been working all night and feel free to just diregard my ramblings as that of a mad man,  sorry to derail this thread

 

Personally, I've always considered "analog" and "digital" to refer to how information is stored and transmitted, not the actual medium itself. Digital simply means that the information is stored via absolute "On" or "Off" levels, with various standards determining at what analog points those states exist, but the actual medium used is irrelevant. Since they don't possess any (meaningful) mid-state, relays are technically digital. Sure, some people consider mechanical switches to be 'analog', and it convenient enough in day-to-day conversation, but I'm not sure the definition really holds up under scrutiny.

 

[zenpunk]

I always thought Einstein was the analogue man with is disdain of anything to do with quantum physics and mechanics????  Anyway, were is the OP and his magic little box?

 

[Telstar]

So, who sells this filter?

 

[Hybrys]

Wish we knew.  Has anyone PMed the OP yet?

 

[bearbb]

Sorry for the late reply in this thread. My friend sold this filter to me. So I need to asked him where he got it.
 
As for playing with power, I tried different combinations, may be I can share some of my experiences here:
 
1. netbook + ac adaptor - sound ok but not as "solid" (or you can say powerful) as traditional atx psu
2. netbook + battery - not good, the sound is so "flat", no emotion inside.
3. desktop pc (dedicated to music playing) + traditional atx psu - the sound is better, more poweful than netbook ac adaptor or battery
4. desktop pc (dedicated to music playing) + external psu (ST-400EAZ or ST-500EAZ from seventeam) - sound good, cleaner and more solid than the above combination
5. desktop pc (dedicated to music playing) + external psu (ST-400EAZ or ST-500EAZ from seventeam) + psu filter - sound really good, I can't say it's the best, as you know there is always something better than "the best" . The sound is clear, I hardly feel any noise, I just feel good when I listen to this setup.
 
What I am going to try:
 
1. picopsu 120W and 150W
2. Winmate DC-DC 130W psu (review here: http://www.silentpcreview.com/Winmate_DD-24AX)
 
Since I want to change my itx case to other itx case, but most of them require pico psu. I tried some cheap pico psu before, but I still think the sound is not as solid as traditional atx psu.Hopefully these 2 pico psu can give me some surprise
 
Power cable also play a very important part. If you can find a good power cable, or DIY by yourself, I think it can improve the sound quality a lot.

 

[xnor]

Quote:

1. netbook + ac adaptor - sound ok but not as "solid" (or you can say powerful) as traditional atx psu
2. netbook + battery - not good, the sound is so "flat", no emotion inside.
3. desktop pc (dedicated to music playing) + traditional atx psu - the sound is better, more poweful than netbook ac adaptor or battery
4. desktop pc (dedicated to music playing) + external psu (ST-400EAZ or ST-500EAZ from seventeam) - sound good, cleaner and more solid than the above combination
5. desktop pc (dedicated to music playing) + external psu (ST-400EAZ or ST-500EAZ from seventeam) + psu filter - sound really good, I can't say it's the best, as you know there is always something better than "the best" . The sound is clear, I hardly feel any noise, I just feel good when I listen to this setup.
 
[...]
Power cable also play a very important part. If you can find a good power cable, or DIY by yourself, I think it can improve the sound quality a lot.

Holy moley!

 

[leeperry]

so I guess we'll never know what that mysterious box is..

 

[doctorcilantro]

Did you try floating the ground pin on your AC brick? Without the filter of course. Tell us the result. Does the noise vanish?
 
I have tried Pico 120, Winmate w/ the Lite-On AC brick that Electrodacus recommends, and the stock dc-dc supply that came with OrigenAE M10 case.
 
All have noise problems because of improper grounding relationship between chassis and ALL three dc-dc converters (5 PSUs total were tried, 3 computers, Lynx AES16 and AES16-E, 2 locations, etc, etc.) The only Pc that had no noise problem was a freaking Dell. Go figure.
 
Floating the PC ground eliminated major cpu/gpu/psu noise from signal chain; next step is to re-ground PC (Zotac ION 330 ATOM), and float pin 1 on AES cables running from Lynx AES16 to DAC....that should work and be a lot safer.

 

[Telstar]

I didnt have any problem with either the OrigenAE stock psu nor the Winmate.
Go figure
Quote:

I have tried Pico 120, Winmate w/ the Lite-On AC brick that Electrodacus recommends, and the stock dc-dc supply that came with OrigenAE M10 case.  
All have noise problems because of improper grounding relationship between chassis and ALL three dc-dc converters (5 PSUs total were tried, 3 computers, Lynx AES16 and AES16-E, 2 locations, etc, etc.) The only Pc that had no noise problem was a freaking Dell. Go figure.

 

[rasputyn]

So, still no info where to buy this? IT looks like it's not homemade.

 

[nagual]

Quote:

Isn't it just much easier to buy a low ripple PSU like any Corsair brand PSU?
But yes, you are right in saying that for a soundcard setup, the computer PSU is vitally important in sound quality. The bigger the ripple = more distortion = decreased sound quality.
USB DACs bypass the computer PSU so there's no need to improve the computer PSU if have an external setup.

Theoretical question:
I´ve read somewhere, that switching PSUs  use ultrasonic frequency (Mhz), so the ripple wouldn´t be audible.
Does it proceed ?
 

 

[terryeh]

chineskiwi suggested a good PSU like a Coursair and I'm here to tell you that this approach (the high road), is flawed! My new Coursair has noise and it is not a steady background hiss. But an intermittent  noise that is large when heard between the actual content.  Of course that is why I am here, to solve this issue. 
 This has been suggested by a guy who builds audio boards : 1nK/10nF/100nF/1uF ceramic/film capacitors, all in parallel. I am embarrassed to say I don't know if he wants this on the + or  -  side.
The audio file types don't ask what type of PSU you are using, they seem to expect the problem from any computer PSU. I had hoped  they where nit picking audio files, and that their definition of noise was well...nit pick'n; But no, this is major by any ones standards.
 Grounding issues are large with audio boards. I've never understood the science behind "to ground or not to ground" but one or the other usually solves lots and floating the PSU ground may be a good idea. not sure exactly how to do that, and you don't want to get that wrong.
 
Terry