【體驗CAS，愛與恨的交集】

nicknick

StevenTam 發表於 2012-10-25 13:52
再次謝謝各位C-hings的關注和支持，沒想過這分享能在這引發如此大的回響，無疑也為我注入了一份原動力在將 ...

是的，單單玩電已經有很多不同的取向與玩法，之所以玩hifi可以千變萬化，討論極都討論不完。

我玩電的部份是玩得最遲的，即係到依家都未開始玩電，另一角度的意思是我感受到它的複雜及高深，一想到這方面就不敢貿貿然踩入這門檻，我仍只是在門外躊躇不敢前進。

sealteam4

nicknick 發表於 2012-10-25 14:25
是的，單單玩電已經有很多不同的取向與玩法，之所以玩hifi可以千變萬化，討論極都討論不完。

我玩電的部 ...

題外話：以nick兄對音樂的追求和熱誠，完全唔搞電源線甚是不解
              我相信nick兄不動還不動一動就可能不得了，一升就可能是某旗艦
              其實如果作短期過渡性投資 (我就長期過渡的)，一些平價的電源線其實都值得先行用著
              例如我用緊的DDL都唔錯.......如有需要我可以帶著哂上來等師兄試下 (師兄見多識廣，都應試過好多名線，我呢個好心建   
              議 希望師兄唔好笑我

Lohengramm

kenneth_obee 發表於 2012-10-25 12:34
"PICO powersupply" might not be less noisy than a good ATX-standard PSU which has good filtering c ...

K-Obee hing,

If you don't mind my further elaboration.  I would like to share what I got these years of trial.

You may think carefully the difference between

i) a traditional PC transformer (say 600W)  versus
ii) a PICO powersupply powered by a blackbox powerbrick
iii) a PICO powersupply powered by a Linear power supply module

iv) ... ... other insane way to do... ...

I haven't checked i) ii) iii) with oscilloscope ( the output ripple stability, generally speaking, less ripple = less noise ); however, IF you consider the "pollution" of a piece of appliance, then you may know what I'm taking about.

The key difference between 3 of them, illustrate physically as below.

i) Wall socket --> PowerCable --> traditional PC transformer --> MotherBoard
ii) Wall socket --> PowerCable --> blackbox switching powerbrick --> PICO PSU --> MotherBoard
iii) Wall socket --> PowerCable --> Linear power supply module --> PICO PSU --> MotherBoard


for i) and ii),

As said earlier, you are right; we don't know who is better:  i) maybe better on ripple stability, while ii) maybe better due to no spinning parts, etc.  But I think i) tends to be quietly better due to general worse quality of blackbox powerbrick (they are really very noisy ! )

for iii) it's abit interesting here.  You can think of a "quiet buffer", because of the presence of Linear power supply module.

Inside a Linear PowerSupply, again, it has a Transformer ( most of them are "R" core, e.g. Teradak ), rectifier, filtering stage and regulator IC + caps to generate a more stable Voltage of supply to feed your PICO.

This Linear Power Module, in fact, acts as a "Buffer" noise gate against PICO itself, preventing the PICO switching noise from feeding / leaking backwards to pollute the WallSocket Direction...

Illustrate below as:

ii) Wallsocket (contamination) <---- contaminated PowerCable <---- (contamination) blackbox switching powerbrick pollution
iii) Wallsocket <---- PowerCable <---- PowerCable <---- Linear PowerSupply Module


This is why I said: a Linear Powersupply Module paired with a PICO should be better than a PC transformer based powersupply.
It's because you have lessen the pollution leaking out to contaminate other circuit.

obee

Lohengramm 發表於 2012-10-26 01:07
K-Obee hing,

If you don't mind my further elaboration.  I would like to share what I got these ye ...

I see, thanks for sharing

bei_hillgrover

Lohengramm 發表於 2012-10-26 01:07
K-Obee hing,

If you don't mind my further elaboration.  I would like to share what I got these ye ...

想請教Lohengramm hing, 其實能否在DATA+Noise進入DAC之前以USB-SPDIF Convertor或Entreq USB cable(接地盒）作Galvanic isolation從而filter out Noise呢?　

liclic

Lohengramm 發表於 2012-10-25 12:39
nicknick hing,

I think I've seen K-obee hing in avf.  

Welcome loh 兄!

Lohengramm

bei_hillgrover 發表於 2012-10-26 09:10
想請教Lohengramm hing, 其實能否在DATA+Noise進入DAC之前以USB-SPDIF Convertor或Entreq USB cable(接地 ...

mm...  Difficult question be honest...  I try my limited to answer and hope some GuRu turning up to further elaborate.

Firstly, you have to know what is Galvanic Isolation.  I  ( copy and paste some explanation from the web )

Galvanic Isolation - Electrical isolation of a type that no direct electrical connection exists between the two sides being isolated. Common forms of galvanic isolation are optical and transformer.  ( quoted )

Galvanic Isolation - A means of interconnecting two circuits which prevents an unacceptable current from flowing as a result of potential difference (both AC and DC) between the circuits.  ( quoted )

Optical isolation uses light as the isolating means and converts the input signal to light and then converts the light back to the output signal. It is a form of galvanic isolation." ( quoted )

Galvanic isolation is generally used to isolate the detrimental effects of two different circuits being connected together. The most common reason isolation is used to prevent is a ground loop. Isolation is also sometimes used to prevent noise and surges from passing between circuits. ( quoted )

Galvanic isolation is a principle of isolating functional sections of electrical systems to prevent current flow; no metallic conduction path is permitted. Energy or information can still be exchanged between the sections by other means, such as capacitance, induction or electromagnetic waves, or by optical, acoustic or mechanical means.

Galvanic isolation is used where two or more electric circuits must communicate, but their grounds may be at different potentials. It is an effective method of breaking ground loops by preventing unwanted current from flowing between two units sharing a ground conductor. Galvanic isolation is also used for safety, preventing accidental current from reaching ground through a person's body. ( quoted from wiki )

From the above explanation, generally speaking, I would say they are not sharing the Common Ground.  Physically speaking, the ground wire is not metally connected directly.

I think you are refering this graph right??




In short, they do help on the noise aspect

bei_hillgrover

Lohengramm 發表於 2012-10-26 23:20
mm...  Difficult question be honest...  I try my limited to answer and hope some GuRu turning up t ...

Lohen兄，小弟就是想討論一下將上游的noise隔離後，就不用在源頭對電源做多重淨化。

nicknick

sealteam4 發表於 2012-10-25 18:09
題外話：以nick兄對音樂的追求和熱誠，完全唔搞電源線甚是不解
              我相信nick兄不動還不動一 ...

差點漏了眼看不到sealteam兄回文.....

又給你看穿了！我不是不想攪，而是像之前所說，因為知道它重要更不敢貿貿然攪，師兄的心意小弟感激，當然不會笑你，之前也有其他師兄帶過AET HIN電源線來我處家訪放在AV系統，也有明顯的改善，HIN不算很貴，只是我的壞性格給你講中了，我不想太多「過渡期」的動作，想盡量一擊即中（通常按自己奄尖的要求一升就.....），加上最近比較手緊，未有心機好好計劃電源處理的升級，唯有慢慢來。

Lohengramm

bei_hillgrover 發表於 2012-10-27 09:51
Lohen兄，小弟就是想討論一下將上游的noise隔離後，就不用在源頭對電源做多重淨化。 ...

Dear Bei-hill hing,

your question confuses me.  Up-stream and the Source ...  are they not the very beginning part ??

anyway, no matter or what, every every tiny bit of better power quality will help in a certain extend; especially in the Digital Domain.

If my guess is correct for your question, do you mean : If you put all effort on the USB / SPDIF convertor powersupply, then you don't need to care of those coming from.   e.g. You have a storage device feeding the music data thru USB cable, and connect to your U/S convertor and then connect to a DAC, illustrated below:

e.g. i) NAS / Streamer ----ii) ( usb cable ) ----> iii) USB-SPDIF convertor ---- iv) ( Coxial cable ) ----> v) DAC

You have 5 parts here.

My answer and past experience is : IF you ...

i) use better quieter powersupply to feed your streamer
ii) better USB cable

It still will improve the sound; namely more details, blah blah blah.

for iii), iv), v) we don't have to mention.  we all know there will surely be improvement.

But, you may ask WHY doing i) and ii) still improve ??  Aren't they simply digital 01010101 ?  

I have been asking / searching this answer for many years... and recently, thru asking from my master mentor, I finally know why.

Before telling what I find, people may wonder, or even Criticize this is BS.  Anyway, no matter or what, by following the phenomenon / and assumption, I have many break thru in my CAS journey.

We should treat 0101010101 behaves like also Analogue.    Oh... Bull Shit !  0 is 0, 1 is 1, there is no 0.5 !

Well, they are only correct 50%.  And have missed a point that how a machine or computer read something as 0 or 1 ??

This is the crucial point.

Actually, there indeed has a mil sec of 0.5 / 0.3 / 0.6 / 0.4  etc... so many variable numbers...  they way computer transcribe them simply have a "logic" / " logrithm" / " protocol" what-so-ever ( as I am a tech guy anyways ) to determine when it should be treated 1 and when it should be treated as 0.   

It's simply like a slope of cutting point ...  
e.g.

if it's < 0.51 then, it will be treated as 0
if it's > 0.51 then, it will be treated as 1

Noise, in here, you can think of some tiny 0.004, 0.003 units...
say, in a well treated electrical environment, there will be lesser of these tiny units...
however, in a very noisy high switching component environment, there will be shit loads of these tiny units or even huge units...

If we recalled the earlier example, the "protocol" cutting point is 0.5

damn less noise : 0.5 + 0.0001 = 0.5001 , oh, it is < 0.51, it will be treated as 0
very noisy : 0.5 + 0.02 = 0.52, oh it is > 0.51, it will be treated as 1

The above example shows you how discrepacy formed in the digital  data domain, but not yet in a Time-line fashion ( Jitter ).


I hope this can help.