ODAC - general and technical discussions - Page 6 - diyAudio
Go Back   Home > Forums > Commercial Sector > Manufacturers > Head 'n' HiFi - Walter

Head 'n' HiFi - Walter At Head 'n' HiFi we will provide you with the finest Audio equipment and parts for a reasonable price. We will also host Group Buys on request, this includes production of PCB's from our trusted manufacturer and sourcing of the parts at lowest prices. We also have manufacturers for enclosures and panels at hand. Once we host a project we will re-stock it frequently depending on demand, you will never miss out on a project again.

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 1st October 2012, 05:44 PM   #51
swalter is offline swalter  Switzerland
life is beautiful...
diyAudio Member
 
Join Date: Jan 2012
Location: Switzerland
Quote:
Originally Posted by DoktorSteve View Post
Hi Stefan, have you noticed a long mute on the ODAC? I think Foobar closes the USB connection when you change tracks manually and the ODAC then mutes. To me the mute time is too long and I loose a couple of notes when the new track starts.

Have you seen any reference to changing the time constant of the mute circuit? I think you need to change C120 to something a lot smaller than 1uF. Maybe we need to ask the elusive NWAVGUY.Click the image to open in full size.

Steve
hi DoktorSteve,
do you experience this behaviour only with your first track or every track you play? I do not use foobar and never had this kind of issue. might be some buffer settings in foobar itself that cause the delay?
I have not heared from NwAvGuy for a couple of weeks now, hope he is OK. Maybe George as can comment on your query...

Stefan
__________________
everything O2 and ODAC related can be found here: www.headnhifi.com - your DIY and audio resource
or have a peek in our vendor forum: http://www.diyaudio.com/forums/head-n-hifi-walter/
  Reply With Quote
Old 3rd October 2012, 01:09 AM   #52
boris81 is offline boris81  United States
diyAudio Member
 
Join Date: Oct 2009
Location: white plains, ny
Default phase performance

I believe this issue was mentioned on NwAvGuy's blog somewhere but I'd like to bring it up again and get more opinions. There is a significant phase wrap at 2kHz. I'm not going to argue whether it's audible or not since I just got the ODAC and so far I like it.

I guess I'm more interested in what is it caused by and whether it's possible to be fixed in later revisions.

I measured the ODAC with my very old Creative Audigy 2 ZS sound card. Both produce extremely linear frequency response. The TDH measurement is dominated by the sound card's noisy input so it does not represent actual performance. There is a 360 degree phase wrap at 2kHz on the ODAC output. The ODAC was also 8dB more quiet but I compensated for that to make the measurement more comparable.

Green = Audigy2 OUT -8dB -----> Audigy2 IN
Red = ODAC OUT -----> Audigy2 IN
odac.png
  Reply With Quote
Old 3rd October 2012, 09:26 AM   #53
diyAudio Member
 
Join Date: Dec 2010
Location: Northants
Hi Stefan,
it looks like the pad under C120 has been reworked - I guess the DACs were a bit quiet with the mute pin tied to ground ! I changed C120 to 3.3uF but I don't think it reduced the mute time. I saw another design using 2.2uF so I wonder if 22uF is not correct in the schematic.
The mute is only a problem with Foobar 2000. I can see the music appear in the graphic display then the sound starts. 2.2uF and 110k would give a time constant around 0.25s which seems about right. I may just bypass the 110k with 10k and see if that makes a difference.
Steve
  Reply With Quote
Old 3rd October 2012, 06:23 PM   #54
diyAudio Member
 
Join Date: Nov 2010
Location: Toronto
Yes, the card was too quiet with the mute pin shorted to ground.

The values selected for the RC were to minimize the 'power on' pop. (RC time constant to release the mute ) This pin has no effect on inter-track muting.

George Boudreau
Yoyodyne Consulting.
  Reply With Quote
Old 3rd October 2012, 07:15 PM   #55
miero is offline miero  Czech Republic
diyAudio Member
 
Join Date: Jun 2011
Location: Prague
George, can you update the schematics for new revision please?
I'd like to fix it on my first-batch ODAC. Thanks.
  Reply With Quote
Old 3rd October 2012, 07:23 PM   #56
diyAudio Member
 
Join Date: Dec 2010
Location: Northants
Thanks for the reply George.

To be honest I had never even connected the odac with the O2 powered up before so I don't know what the power up click was like. Now I get 3 slight clicks when I do this. I can't find the cap I took off so I will have to live with it!

The inter track muting is still a bit of a mystery then:
I only get it with the ODAC not with the internal soundcard or my UCA222.
I get it with both Foobar and Media Player but it may be more noticable with Foobar.
The normal transition from the end of one track to the start of the next is no problem - only the manual selection of the new track.
  Reply With Quote
Old 3rd October 2012, 07:28 PM   #57
diyAudio Member
 
Join Date: Dec 2010
Location: Northants
Miero, I think there is no new revision. The change I made was due to a misunderstanding. I think the error in the tracking was in the second batch and was fixed before release - it would have been pretty obvious as there would be no sound!
  Reply With Quote
Old 3rd October 2012, 08:28 PM   #58
diyAudio Member
 
Join Date: Nov 2010
Location: Toronto
DoktorSteve PM me and I will send you a replacement cap
  Reply With Quote
Old 3rd October 2012, 08:30 PM   #59
diyAudio Member
 
Join Date: Nov 2010
Location: Toronto
You are correct. The pad for the cap C120 'grew' into a stitching via and shorted to mute pin. This was a screw-up on the pcb manufacturers side but it required we 'hand adjust' the pad to clear the via.
  Reply With Quote
Old 21st October 2012, 10:53 PM   #60
Neil_J is offline Neil_J  United States
diyAudio Member
 
Join Date: Feb 2005
Location: Florida
I'm wondering why the Cbyp cap on the MIC5205-3.6YM5 (pin 4) was omitted? Does it run better without it? Or would it improve noise to add it?
  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
ODAC - European and Worldwide pre-orders swalter Head 'n' HiFi - Walter 207 19th July 2014 10:32 PM
ODAC offerings from Various Vendors swalter Vendor's Bazaar 216 15th April 2013 04:53 AM
Class D discussions mskeete Class D 16 19th March 2004 07:27 AM
Discussions on Balenced Amplifers theChris Chip Amps 24 6th January 2004 03:40 PM


New To Site? Need Help?

All times are GMT. The time now is 06:47 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