Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

Oversampled DAC without digital filter vs NOS
Oversampled DAC without digital filter vs NOS
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 4th March 2019, 10:35 AM   #11
analog_sa is offline analog_sa  Europe
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Cascais
Oversampled DAC without digital filter vs NOS
So, is this true for upsampling too?
  Reply With Quote
Old 4th March 2019, 10:36 AM   #12
Jakob2 is offline Jakob2  Germany
diyAudio Member
 
Join Date: Jun 2004
Location: germany
As Abraxalito already said, it is only "oversampling" or "upsampling" if the digital filter process (interpolation process) that removes the previously existing images around the original sampling frequency (and itīs multiples) is included.

Unfortunately (i hope it does not add confusio mentioning this) there is a inconsistency in the nomenclature, as in system theory the block that does increase the sampling rate is also called quite frequently a "upsampler" followed by an so-called "interpolator" block.
But on a device level (DACs, digital players and so on) "upsampling" and "oversampling" always means the complete process of digital low pass filtering and raising the sampling rate.
  Reply With Quote
Old 4th March 2019, 11:18 AM   #13
ygg-it is offline ygg-it  Italy
diyAudio Member
 
ygg-it's Avatar
 
Join Date: Feb 2008
Location: ITALY
So, I couldn't have the chance to listen to "oversampled" DAC machines "without digital filter" simply because they don't exist. Correct?

If not, I'm lost with definitions....
  Reply With Quote
Old 4th March 2019, 11:25 AM   #14
abraxalito is offline abraxalito  United Kingdom
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Send a message via Yahoo to abraxalito
It depends on your definition of 'digital filter'. I built a 2X OS DAC without a filter implemented by means of digital multiplier and digital accumulator - it used analog multipliers (a resistor network) and an analog accumulator (summing currents). But I doubt if such a DAC exists commercially so you're probably right.
__________________
I know you think you understand what you thought I said but I'm not sure you realize that what you heard is not what I meant - Alan Greenspan
  Reply With Quote
Old 4th March 2019, 11:33 AM   #15
hellokitty123 is offline hellokitty123  United States
diyAudio Member
 
Join Date: Dec 2017
Location: Connecticut
Quote:
You've still got images which start at 24.1kHz
Are images @ 24k and above really such a bad thing if your amplifier/speakers can handle it?
  Reply With Quote
Old 4th March 2019, 11:42 AM   #16
abraxalito is offline abraxalito  United Kingdom
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Send a message via Yahoo to abraxalito
The answer to that would depend on what 'can handle it' means.
__________________
I know you think you understand what you thought I said but I'm not sure you realize that what you heard is not what I meant - Alan Greenspan
  Reply With Quote
Old 4th March 2019, 11:49 AM   #17
hellokitty123 is offline hellokitty123  United States
diyAudio Member
 
Join Date: Dec 2017
Location: Connecticut
Not blowing up speakers, not distorting due to HF content.
  Reply With Quote
Old 4th March 2019, 11:52 AM   #18
Jakob2 is offline Jakob2  Germany
diyAudio Member
 
Join Date: Jun 2004
Location: germany
Quote:
Originally Posted by hellokitty123 View Post
Are images @ 24k and above really such a bad thing if your amplifier/speakers can handle it?
Of course difficult to ensure for each and every amplifier in the world, but imo generally chances are low that amplifiers/speaker can handle it.

Letīs assume that in the original content a spectral component around 1 kHz with full scale level exists; if no filtering is given (even not an analog filter) it follows that at the Fsample - 1 kHz and Fsample + 1kHz (means at 43.1kHz and 45.1 kHz, in case of a 44.1 kHz sample frequency) full scale signals exist and at the muliples of the sampling frequency the same happens,i.e. NxFsample - 1 kHz and NxFsample + 1 kHz (N = 2,3,4,5....).

And that is just an example for one spectral component, usually there are a lot more especially so for records suffering from "loudness war" .

@ Ygg-it,

yes, or iow any player that does not filter the spectral images should not be denoted as an "oversampling" player to keep the meaning of the terms.

If one uses for example shorter impulses to lessen the impact of the amplitude level weighting introduced by the zero-order-hold function in a 44.1 kHz system, it is not oversampling and should be denoted by another term.

Last edited by Jakob2; 4th March 2019 at 11:57 AM.
  Reply With Quote
Old 4th March 2019, 12:02 PM   #19
abraxalito is offline abraxalito  United Kingdom
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Send a message via Yahoo to abraxalito
Quote:
Originally Posted by hellokitty123 View Post
Not blowing up speakers, not distorting due to HF content.
I very much doubt images will trouble speakers. I do think amps in general distort more due to excess HF. Its not typically heard as distortion though, the subjective effect is either exaggerated leading edges or perhaps reduced dynamics, or both.
__________________
I know you think you understand what you thought I said but I'm not sure you realize that what you heard is not what I meant - Alan Greenspan
  Reply With Quote
Old 4th March 2019, 12:04 PM   #20
diyiggy is offline diyiggy
diyAudio Member
 
Join Date: Jan 2019
Default The most important is the upsampling in the reccording

Is it correct to assume the ringings & artifacts are already pushed for the biggest amount above the ears fequencies during the analog to digital reccording. And it is where it is mostly important?

Seems all the reccordings are upsampled at 88/98 K Hz or 171/192 Khz to remove at the best phantom images and sub harmonics artifacts digitals filters and mixings add and then just print on CDs a 44.1 Hz "extrapolation" of the reccording. And it doesn't mean the reccording engineers do not use some others artifacts which can be heard too : dynamic compressing, lot of mixing, etc to glue to the limit of Redbook. It may be a better subjective hearing of micro dynamics which is "loved" by NOS enthusiats?

Question is whether our hearing system gives a good enough "natural" low pass filter with all those "unatural" reccording. And materials with upsample above the Redbook stay rare.

Do we really need a steep analog filter to help the hears when not using digital filters? Sorry if mx the concepts, my understanding of it is low.
  Reply With Quote

Reply


Oversampled DAC without digital filter vs NOSHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
FIR Digital Filter DSP neededandwanted Parts 1 9th April 2009 01:44 AM
Oversampled TDA1541(a) I2S format? andrew_whitham Digital Source 25 17th April 2006 07:10 PM
Toshiba 3950 w/ John Swenson Mod vs. 1543 Non-Oversampled Dac Tuber Digital Source 6 28th November 2004 01:42 PM
Kwak clock and Guido Tent oscillator in a TDA1541 zer-oversampled cd player Dr.H Digital Source 4 10th May 2003 09:42 AM
Digital (DSP) filter magnus Digital Source 12 9th February 2003 12:17 PM


New To Site? Need Help?

All times are GMT. The time now is 10:50 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki