Behringer DCX2496 digital X-over - Page 315 - 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 10th October 2011, 02:27 AM   #3141
diyAudio Member
 
Join Date: Nov 2010
Quote:
Is it ok to copy some commentary on here, and to attach the pdf ??
Please post it here.
  Reply With Quote
Old 11th October 2011, 01:30 AM   #3142
diyAudio Member
 
MurphyUHF10's Avatar
 
Join Date: Oct 2010
Location: Melbourne
Quote:
Originally Posted by 4pyros View Post
Please post it here.
Hi 4pyros,

I have attached the pdf for the front panel deactivations..

There is quite a lot of good dialog on this topic in the yahoo users group, but in summary, this is the mod:

"..I choose to turn off/on in the same time both the LCD and the display LEDs, so I
used a double pole switch:
- One pole to invert RST on the display to RST from DSP or to GND. It deactivate
LEDs but not front panel buttons.
- Second pole to switch on/off backlight anode on the LCD
RST on LCD is still connected permanently to RST on DSP even if re-routed
through my new cables. So LCD is always active but dark!

Of course you can choose to have the LCD always on and use a single pole switch..."


Hope this helps!

DCX2496 Front Panel Deactivation.pdf

CM
  Reply With Quote
Old 11th October 2011, 01:34 AM   #3143
diyAudio Member
 
MurphyUHF10's Avatar
 
Join Date: Oct 2010
Location: Melbourne
Quote:
Originally Posted by mhelin View Post
Quite a lot RF EMI there inside the DCX, maybe a new PCB design for the "mother board" would be needed:

Signal from DAC's to I/O card

Unless you can't EMI shield the mother board then the only viable option to get a clean environment for the analog circuits is to use an optical digital (TOS/ADAT-) link outside of the rack box to external DAC's, right?
Hmm, interesting.. Surprising, none of the DCX "big guns" have commented on this in all the mods mentioned?? Perhaps it's negligible??
  Reply With Quote
Old 11th October 2011, 02:13 AM   #3144
diyAudio Member
 
linuxworks's Avatar
 
Join Date: Jul 2008
Location: santa clara, CA
is there an equiv for the DEQ2496? that also needs 'visual muting'
__________________
My Photostream:http://www.flickr.com/photos/linux-works/
  Reply With Quote
Old 11th October 2011, 07:56 PM   #3145
ds23man is offline ds23man  Netherlands
diyAudio Member
 
Join Date: Oct 2006
Maybe the Hypex DLCP, if they finaly get time to work on it!

Regards Gerhard
  Reply With Quote
Old 11th October 2011, 08:20 PM   #3146
diyAudio Member
 
autopoiesis's Avatar
 
Join Date: Mar 2007
Question front panel deactivations - photo anyone?

Quote:
Originally Posted by MurphyUHF10 View Post
Hi 4pyros,

I have attached the pdf for the front panel deactivations..
I looked at the pdf and (ahem) don't quite understand it - does anyone have a photo of a completed mod?
__________________
Dogs have masters; cats have staff
  Reply With Quote
Old 12th October 2011, 11:35 AM   #3147
diyAudio Member
 
Join Date: Apr 2003
Location: Tampere Finland Europe
Quote:
Originally Posted by MurphyUHF10 View Post
Hmm, interesting.. Surprising, none of the DCX "big guns" have commented on this in all the mods mentioned?? Perhaps it's negligible??
Don't think it's negligible, the RF will cause noise in opamps and required for EMI filtering and special layout (enough caps everywhere, close ground layer next to signal) to avoid emitting the RF noise. The DXC pcb is very bad design EMIwise. The guy who made these measurements is pro electronics designer and knows this stuff very well (actually he's happens to be also one of the guys behind the WinISD speaker box designer sw). I'd say 99% of all DIY digital stuff on this forum totally neglects EMI issues. One problem is that you need expensive measurement devices to measure RF upto 1 GHz.

Anyway, here are another two interesting plots on RF EMI nearfield measurements:

DCX off

DCX on

I think there are only two possible solutions, either redesign the PCB or build optical digital outputs for DCX. Well, some mods like new clock are good anyway (the less jitter the less noise there will be).


Electromagnetic interference - Wikipedia, the free encyclopedia
  Reply With Quote
Old 12th October 2011, 12:15 PM   #3148
diyAudio Member
 
MurphyUHF10's Avatar
 
Join Date: Oct 2010
Location: Melbourne
Quote:
Originally Posted by mhelin View Post
I think there are only two possible solutions, either redesign the PCB or build optical digital outputs for DCX.
What about a simple metal cover/shield over the DSP board??

CM
  Reply With Quote
Old 12th October 2011, 12:43 PM   #3149
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Kona, Hawaii
Blog Entries: 4
The DAC and ADC chips sit right on that DSP board.
  Reply With Quote
Old 12th October 2011, 06:04 PM   #3150
diyAudio Member
 
Join Date: Apr 2003
Location: Tampere Finland Europe
Quote:
Originally Posted by Pano View Post
The DAC and ADC chips sit right on that DSP board.
Yes, maybe you could build a new DAC board and put it into shielded case a little further from the DSP board. Like replace the analog board with a one properly designed digital+analog one, and a separate PSU of course. You could get the I2S signals quite easily from the DAC pins (the clock signals) and PCB nearby (from the three resistors next to DAC's). You might even use the same DAC chips as they are fine (if you can delsoder them, QuickChip makes good desoldering solder for that purpose).

Last edited by mhelin; 12th October 2011 at 06:07 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



New To Site? Need Help?

All times are GMT. The time now is 02:38 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