ackoDAC based on ES9018 - Page 6 - diyAudio
Go Back   Home > Forums > Source & Line > Digital Line Level

Digital Line Level DACs, Digital Crossovers, Equalizers, 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 17th October 2009, 02:06 PM   #51
Banned
 
Join Date: Nov 2005
Location: McKinney, TX
Quote:
Originally Posted by tritosine View Post
that PCB is OK... but I can't justify the 65Eur+shipping on the IC. Especially, because people use it for stereo, its just like the good old tda1541s2 "bidness" (and I tought that must be a fad) ... (...)
I recommended and co-design an ad1955 D/A right now by-the-way .

Who knows, some of the ESS chips might be EOL sooner than we think, once the marketing department pulls a string
WOW that is pricey! Damn the taxes!!!!
  Reply With Quote
Old 17th October 2009, 03:40 PM   #52
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: Dublin
Agreed, tritosine, about the IC, it's way over priced but again based on Curly's logic we're paying for their work in designing a new & unique oversampling methodology which hadn't been done before. Wow Curly, I'm surprised you didn't know this

This hobby is expensive enough as it is without over-paying for simple jobs within the capability of a fair number that frequent this forum. Remember, that you will have to solder the 0.05 inch pitch, 64 LQFP IC to this board - a job probably requiring more skill than doing the layout of the board

Thanks, Curly, I will take up your invitation to do this through Expresspcb & share it with 3 of my friends - as much because shipping charges from Oz to Irl don't make sense
  Reply With Quote
Old 17th October 2009, 03:46 PM   #53
diyAudio Member
 
Join Date: Aug 2008
Actually I know at least one digital audio company doing oversampling in this style , that is multplying by 1024x (+?)... (uh).
...way before ESS. Not to mention, this is textbook stuff.

Last edited by tritosine; 17th October 2009 at 03:50 PM.
  Reply With Quote
Old 17th October 2009, 04:02 PM   #54
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: Dublin
Quote:
Originally Posted by tritosine View Post
Actually I know at least one digital audio company doing oversampling in this style , that is multplying by 1024x (+?)... (uh).
...way before ESS. Not to mention, this is textbook stuff.
I think you'll find that there is enough uniqueness in their design to apply for a patent back in 2006 United States Patent: 7330138
  Reply With Quote
Old 17th October 2009, 04:12 PM   #55
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: Dublin
An easier read is found here: http://www.esstech.com/PDF/sabrewp.pdf

The cost is somewhat akin to the Semisouth Jfets which are running at $50 each or so - You would need 2 to 4 of these for an amp & what do you get for the money - a lower THD (& better sound ala Papa Pass)!

Last edited by jkeny; 17th October 2009 at 04:18 PM.
  Reply With Quote
Old 17th October 2009, 04:17 PM   #56
diyAudio Member
 
Join Date: Aug 2008
Quote:
Originally Posted by jkeny View Post
I think you'll find that there is enough uniqueness in their design to apply for a patent back in 2006 United States Patent: 7330138
Thats about the DPLL part for the ASRC, every ASRC has to have one.
The oversampling/interpolation part is still a 'textbook' zero fitting implementation, and you can't really alter its 'textbook' approach by uploading new coefficients.
It also poses its requirments afaik, linear interpolation is greedy when it comes to stopband attenuation.
  Reply With Quote
Old 17th October 2009, 04:27 PM   #57
diyAudio Member
 
Join Date: Aug 2008
Quote:
"Zero Stuffing not First Order Hold in up-sample
A first order hold in the over sampling filter results in a
narrower data path and hence less logic, but necessitates
sin(x)/x correction be at a lower rate. No sin(x)/x correction is
perfect and low rate sin(x)/x correction results in frequency
domain imperfections. Zero-stuffing is mathematically more
precise
and results in a sin(x)/x correction at a much higher
frequency and hence any errors are much further out-of-band"
thats what Im talkin about. The rest is debatable, like "low order noise shaping" (is 5th that low ? ) .

Last edited by tritosine; 17th October 2009 at 04:29 PM.
  Reply With Quote
Old 17th October 2009, 04:28 PM   #58
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: Dublin
I'm not going to argue the pros or cons of their design approach - you consider it to be trivial text-book fare & I'm not Dustin, the designer, so I don't know enough to enter into this with you but I have seen it reported widely that they have implemented some clever tricks in their design that hadn't been done before & this is what you're paying for in the price!
  Reply With Quote
Old 17th October 2009, 04:32 PM   #59
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: Dublin
OK, if you must get into this:
Quote:
It is a multibit sigma-delta DAC so the input is highly oversampled using polyphase filters, then the synchronous resampling is done on the highly oversampled data which allows use of a very simple interpolation algorithm.

This is very clever (and patented).

It is a good example of lateral thought. Instead of solving a hard problem (asynchronous resampling at frequencies close to the Nyquist limit) it turns it into an easy problem (asynchronous resampling with a sample frequency way above the Nyquist limit).
  Reply With Quote
Old 17th October 2009, 04:38 PM   #60
diyAudio Member
 
Join Date: Aug 2008
The Sabre is one extreme to me. WAAAAY different than what others do BTW. And I wont go there , no patent infringement is in sight on my behalf.

Last edited by tritosine; 17th October 2009 at 04:41 PM.
  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
WM8816 based pre-amp panson_hk Chip Amps 13 22nd May 2009 02:16 PM
DIY ESL III (based on an ER Audio Kit) jasonlky Planars & Exotics 7 23rd January 2008 07:09 AM
UCD based amp oldmaelstrom2 Class D 3 27th June 2007 10:10 AM


New To Site? Need Help?

All times are GMT. The time now is 06:34 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