Compact disc player sonic differences by various signal procesing devices before DAC - Page 3 - 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 30th December 2011, 09:29 PM   #21
diyAudio Member
 
Join Date: Jan 2008
Location: Virginia
Upsampling with cheap chips discardes some of the good samples and produces fake samples, based on some "coeficients" stored internally in the ROM.

The DSP aproach, because of the generous ammount of RAM, can maintain all the initial samples and generate the intermediate ones based on calculations done in real time.
  Reply With Quote
Old 31st December 2011, 04:06 AM   #22
diyAudio Member
 
Join Date: Dec 2003
Location: Sydney
Quote:
Originally Posted by SoNic_real_one View Post
I have the Denon AL24 Processing Plus.....
Worked on few Denon CD and DVD players with DXP6001AF....noisy mf... Denon implementation is even noisier... quite appalling..... unbelievable would be the better word.

Boky

Last edited by Extreme_Boky; 31st December 2011 at 04:07 AM. Reason: get the right part number...
  Reply With Quote
Old 31st December 2011, 04:15 AM   #23
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 99
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Quote:
Originally Posted by SoNic_real_one View Post
Upsampling with cheap chips discardes some of the good samples and produces fake samples, based on some "coeficients" stored internally in the ROM.

The DSP aproach, because of the generous ammount of RAM, can maintain all the initial samples and generate the intermediate ones based on calculations done in real time.
What a load of nonsense! The drawbacks of 'cheap chips' vs DSP are down to the implementation differences. 'Fake' samples will always be produced if the FIR filter isn't a half-band one - that's the only kind which preserves the original samples when upsampling. And - as it turns out - most of the the 'cheap chips' do indeed use half-band filters. One of the advantages of going to DSP is to get away from such limitations - half-band filters by definition allow aliasing and hence violate one of the prime directives of digital audio.
__________________
It doesn't have to take the form of a conspiracy, rather a consensus... James H Kunstler
  Reply With Quote
Old 31st December 2011, 04:59 AM   #24
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Hi,

Quote:
Originally Posted by SoNic_real_one View Post
AD1865 is the best ASRC cip on market.
The AD1865 is a DAC, not an ASRC.

Ciao T
  Reply With Quote
Old 31st December 2011, 05:28 AM   #25
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Hi,

Quote:
Originally Posted by SoNic_real_one View Post
Upsampling with cheap chips discardes some of the good samples and produces fake samples, based on some "coeficients" stored internally in the ROM.

The DSP aproach, because of the generous ammount of RAM, can maintain all the initial samples and generate the intermediate ones based on calculations done in real time.
I do not where you get your information from, but it is plain and simple false.

First, Asynchronous Upsampling, no matter technology is used, MUST re-calculate each and every sample, there is no other way, as original samples and output samples do not line up.

No matter how the intermediate samples are calculated (straightline interpolation, various filter functions etc.) the sample rate converted samples MUST be different from those that where originally present and will contain errors who's magnitude and nature depends how closely sample rate conversion process and signal match each other, or not.

But no matter what, if the sample rate conversion is asynchronous, ALL output samples are "Fake" and no "Real" samples are retained.

Any possible retention of "real samples" could only happen if the upsampling operates with integer ratio's, that is, if we use the special case of upsampling usually called oversampling. This would however only possible if we do not apply a filter during the oversampling process, if a digital filter is employed then again, all samples output by the filter are "Fake".

The above holds equally true if the algorythms are impelemented in a hardware chip (be it an SAA7220 or DF1704 for oversampling or an AD1896 for ASRC) or if they are running in software on a Quad Core i7 with 16GB or RAM.

So, in fact the only way to preserve the "Real Samples" would be to avoid any digital manipulation, that is to operate "Non-Oversampling". If this "preserving real samples" is a goal that meaningful is open to debate.

Ciao T
  Reply With Quote
Old 31st December 2011, 05:36 AM   #26
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Hi,

Quote:
Originally Posted by tiefbassuebertr View Post
DAC IC's are not the subject of this discussion (is my english so bad ? Please read the headline carefully).
Many modern DAC IC's include Digital filters and even ASRC on board. It is rather hard to separate out the "sound of the DAC" from "the sound of the Filter" as a result...

Ciao T
  Reply With Quote
Old 31st December 2011, 05:38 AM   #27
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Hi,

Quote:
Originally Posted by abraxalito View Post
What a load of nonsense! The drawbacks of 'cheap chips' vs DSP are down to the implementation differences. 'Fake' samples will always be produced if the FIR filter isn't a half-band one - that's the only kind which preserves the original samples when upsampling.
Halfband FIR does not preserve original samples. Try it.

Ciao T
  Reply With Quote
Old 31st December 2011, 05:38 AM   #28
diyAudio Member
 
Join Date: Jan 2008
Location: Virginia
Quote:
Originally Posted by Extreme_Boky View Post
Worked on few Denon CD and DVD players with DXP6001AF....noisy mf... Denon implementation is even noisier... quite appalling..... unbelievable would be the better word.

Boky
Yeah, I know the story, NOS all the way is the true light.
Quote:
Originally Posted by ThorstenL View Post
Hi,
The AD1865 is a DAC, not an ASRC.
Ciao T
Thank you, my bad, AD1896...
  Reply With Quote
Old 31st December 2011, 05:52 AM   #29
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Folks,

For those interested in what different filters do, the March Stereophile will feature a review of a Digital Product that offers a very wide selection of digital filters, including "no filters at all" and multiple DAC's.

Many (but not all) of the filters are documented with detailed measurements, though sadly the reviewer did not spend a lot time on the sonic differences, so it is not as interesting as it could be.

During the development of this product I found myself (as well as many others) subjectively preferring minimum phase filters with no pre-ringing preferable to traditional "brickwall - symmetrical impulse response" types, even under blind conditions.

What surprised me however was that I did however NOT prefer the filter of these that was most like Non-Os (that would be one with no pre-ringing and only four cycles of visible post-ringing) but one that is essentially more like the classic LC Brickwall filter on early non-oversampling ADC/DAC Systems (Sony PCM F-1 for example) and first generation Japanese CD-Players, which has 19 cycles of visible post-ringing.

However, in this particular area the preference for the "short"and "long" minimum phase filter was split with no particular pattern of preference notable

Generally Non-Os with some analogue filtering came out on top, followed by "unfiltered" Non-Os and the analogue-like minimum phase filters. Different versions of traditional symmetrical impulse response digital filters where ranked at the bottom and found to be very little different from each other.

Ciao T
  Reply With Quote
Old 31st December 2011, 06:03 AM   #30
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 99
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Quote:
Originally Posted by ThorstenL View Post
Halfband FIR does not preserve original samples. Try it.
Seeing as half-band FIR doesn't suit me as regards technical performance, no thanks, no need to go there. What are you basing your claim on that it doesn't incidentally? I may have misinterpreted the context, I wasn't speaking of async SRC, rather (fixed) integer ratio upsampling. I'm glad to be corrected if you have a reference.
__________________
It doesn't have to take the form of a conspiracy, rather a consensus... James H Kunstler
  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
sonic differences between different operating systems ralf Digital Source 3 7th September 2007 01:07 PM
Converting CAL CL10 5 disc player to a single disc player stoolpigeon Digital Source 0 27th May 2007 01:25 PM
Compact 15" sub - BMS or Precision Devices? DIAR Subwoofers 7 4th January 2007 04:06 PM
Speakers From An Old Sony Compact Disc Deck Receiver borgs Multi-Way 1 14th November 2006 02:20 AM
Sonic differences - discrete vs. integrated? mlihl Pass Labs 15 16th September 2006 03:12 PM


New To Site? Need Help?

All times are GMT. The time now is 09:30 PM.


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