Zen -> Cen -> Sen, evolution of a minimalistic IV Converter - Page 37 - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 23rd October 2011, 03:32 PM   #361
pidesd is offline pidesd  Canada
diyAudio Member
 
pidesd's Avatar
 
Join Date: Apr 2008
Location: montreal (cotes des neiges yo!)
bits are sent in the form of square waves. And square waves, just like any other wave, are never perfect. Converters (some more than other) are sensible to the quality of what it is sent. They interpret them a certain way with all the tools we have given them. For example, take a look at the first page where you can see the analog square wave of the SEN,CEN. That is a nice attempt at a perfect square wave but it isnt.

i also doubt that your computer never misinterpreted a bit but it is possible

Last edited by pidesd; 23rd October 2011 at 03:36 PM.
  Reply With Quote
Old 23rd October 2011, 03:46 PM   #362
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
I am sorry to say that I do not agree with the above arguments.

Firstly an IV converter is a 100% analogue circuit. It receives current signals (from either a MC phono pick-up, or the analogue current output of a DAC). Thus the power supply for the circuit is not too different from those feeding any other analogue circuits.

Secondly, those who read the article will know that the bias circuit, driven by the floating supply, runs in a completely different current loop than the signal current loop. Since current can only flow in a loop, the two are independent of each other. There are no electronic components or circuits that I know of, however imperfect, that do not obey Kirchoff's Law. And Kirchoff's law makes sure that the bias current does not affect the signal current loop, and vice versa.

Thirdly, the square wave as shown in the first page of this thread is feed by a functions generator and has nothing to do with digital signal. The output square wave is "not perfect" because of parasitic capacitances in the JFETs. There are ways and means to reduce the effects of these capacitances to get a more "perfect" square wave, and we do know how. But there is little point in doing so, because at most DAC outputs, some form of LP or reconstruction filter is usually implemented. That is also why there are provisions for Civ on the PCB, to filter off some HF content of the current signal from the DAC.


My 2 cents,
Patrick

.

Last edited by EUVL; 23rd October 2011 at 03:49 PM.
  Reply With Quote
Old 23rd October 2011, 04:12 PM   #363
pidesd is offline pidesd  Canada
diyAudio Member
 
pidesd's Avatar
 
Join Date: Apr 2008
Location: montreal (cotes des neiges yo!)
maybe i am m wrong, but what i wanted to say is that that not every power supply is suitable for good signal (digital) integrity. that a digital signal is not only one and zeros, it is an non-perfect square wave that can be misinterpreted, depending on the dac and related components. At least that how i understand it.

by the way your square waves looks darn good if you ask me

looking foward to build it.
  Reply With Quote
Old 23rd October 2011, 04:23 PM   #364
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
yes, the posting on the previous page is one of many other naive statements written just like it but people who honestly think they know what they are talking about (this is said not in a derogatory way), the whole bits is bits thing has been run over and over and over, in this case the poster even seems to be unaware of the fact that the dac from the point it becomes analogue, to the very point we are dealing with it here, is about as vulnerable low level analogue current conveyed signal as is possible.

Last edited by qusp; 23rd October 2011 at 04:26 PM.
  Reply With Quote
Old 23rd October 2011, 04:35 PM   #365
regal is offline regal  United States
diyAudio Member
 
Join Date: Jan 2004
Location: MD
Quote:
Originally Posted by mfrimu View Post
regal,

With due respect and my limited knowledge I fail to grasp how power supplies would be a problem in a digital circuit. My PC has a 50$ 500w supply and has not missed a single 'bit' ever running at 3Ghz 24hrs/day for 2+ years now, hence I would say the power supply is ample able to deal with mains noise etc.

In low level analog circuits, that is a different story.
jitter, until till you have heard a manster clock powered by low noise power supply vs. smps you wouldn't understand, I didn't either.

Last edited by regal; 23rd October 2011 at 04:52 PM.
  Reply With Quote
Old 23rd October 2011, 04:39 PM   #366
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
Please kindly return to the discussion of IV circuits.


Thanks,
Patrick
  Reply With Quote
Old 23rd October 2011, 04:48 PM   #367
diyAudio Member
 
Join Date: Sep 2011
I think the original messge got lost. I said that in Digital circuits, I did not beleive batteries would be The Great Improovement and hence my PC running for 2 years analogy. This comment was in response to

'I work with robots and vfds in my real job and you wouldn't believe all the issues from poor quality mains.'

As I would be suprised a standard (well designed) power supply would have trouble with digital circuits.
  Reply With Quote
Old 23rd October 2011, 04:56 PM   #368
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
In most "standard" digital circuits such as a computer, the regularity of the timing of the signal (jitter) is not critical for the computation to function.
In digital audio, the digital circuit still functions with jitter, but the results in the audio domain suffers.

If you wish to discuss this further, I think there are many threads in this forum which is a more suitable platform than this particular thread.


Best Regards,
Patrick
  Reply With Quote
Old 23rd October 2011, 05:00 PM   #369
regal is offline regal  United States
diyAudio Member
 
Join Date: Jan 2004
Location: MD
Quote:
Originally Posted by mfrimu View Post

As I would be suprised a standard (well designed) power supply would have trouble with digital circuits.
true but well designed power supplies are a rarity , applies to both sections of the dac, remember the "digial section is still analog signals (no infinite bw in the real world.)

Sorry to get off topic, but running the Cen on batteries only makes sense to lead one use for them the whole dac (of corse with proper post regulation.) I'll shut up.
  Reply With Quote
Old 23rd October 2011, 05:06 PM   #370
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
Perhaps a reminder that the floating power supply swings with the output signal.
Thus, each single ended IV will need its own floating power supply.

That means, e.g., 4x flating supply for 2 channel balanced.


Patrick
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
FOR REGA Turntable>>> The heavy weight + Vta adjuster+ceramic ball prooptiki Swap Meet 1 22nd May 2010 05:57 PM
Multi-DAC: Lynx AES16 -> DIR9001/SRC4392 (-> SRC4192) -> PCM1794A novec Digital Line Level 11 11th May 2010 11:57 AM
> Audio <> music <> quick <> synergy <> angst>? rick57 Everything Else 0 4th May 2007 04:03 PM
&gt;&gt;&gt; cheap 50,000uF 60V capacitors here &gt;&gt;&gt; Lubomir Swap Meet 0 1st February 2007 03:36 PM


New To Site? Need Help?

All times are GMT. The time now is 10:59 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2