Behringer DCX2496 Questions - Page 2

jan.didden · 16th May 2005, 07:03 PM

The schematics:

The middle one is the passive filter, with the balanced resistor values lumped to one side to avoid differential probing.

The lower one is the input circuitry of the DCX; this is interesting, since it has a kind of pre-emphasis; it has a high pass characteristic. Curves to follow.

Jan Didden

jan.didden · 16th May 2005, 07:06 PM

Input pre-emphasis (analog inputs):
Far from level...

Jan Didden

transducer · 17th May 2005, 03:11 PM

Jan, If I understand you correctly, you are saying that the DCX has a sort of preemphasis filter for analog inputs. So how does it deal with the digital input? Do you suppose that there is a similar preemphasis in the digital domain? And what would be the point of this preemphasis? It would be interesting to actually probe the unit and measure it's input circuitry prior to the A/D converter.

Regards,
Ron

Davey · 18th May 2005, 01:53 PM

Ron,

My simulation doesn't show nearly as much "pre-emphasis" as Jan's, but maybe I've got something setup wrong. I'm seeing an approximate 0.9 db shelving action created by the filter. I think the difference is explained by what the load is seen by the circuit. Jan assumed zero ohms because of the two capacitors shunting the voltage divider on the + side of the inverting amplifier.

Anyway, I've looked at the outputs with both digital and analog inputs and they look flat to me. Any frequency contouring that's going on in the analog sections must compensated for in the digital domain somewhere.

Cheers,

Davey.

transducer · 18th May 2005, 02:49 PM

So it's pretty much a non issue. Thanks Davey.

Cheers,
Ron

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Behringer DCX2496	12 Cents	Swap Meet	0	29th July 2007 08:27 AM
Behringer DCX2496	RAAMaudio	Swap Meet	0	19th February 2006 07:15 PM
Behringer DCX2496 questions	noah katz	Digital Line Level	18	23rd October 2005 07:49 PM
Behringer DCX2496 questions	noah katz	Digital Line Level	4	21st October 2005 05:43 AM
Behringer DCX2496 12v ps	Flyingeyepro	Car Audio	0	30th July 2004 08:05 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	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

17th May 2005, 03:11 PM	#13
transducer diyAudio Member Join Date: Mar 2002 Location: Toronto, Canada	Jan, If I understand you correctly, you are saying that the DCX has a sort of preemphasis filter for analog inputs. So how does it deal with the digital input? Do you suppose that there is a similar preemphasis in the digital domain? And what would be the point of this preemphasis? It would be interesting to actually probe the unit and measure it's input circuitry prior to the A/D converter. Regards, Ron

18th May 2005, 01:53 PM	#14
Davey diyAudio Member Join Date: Dec 2001 Location: Bremerton, WA.	Ron, My simulation doesn't show nearly as much "pre-emphasis" as Jan's, but maybe I've got something setup wrong. I'm seeing an approximate 0.9 db shelving action created by the filter. I think the difference is explained by what the load is seen by the circuit. Jan assumed zero ohms because of the two capacitors shunting the voltage divider on the + side of the inverting amplifier. Anyway, I've looked at the outputs with both digital and analog inputs and they look flat to me. Any frequency contouring that's going on in the analog sections must compensated for in the digital domain somewhere. Cheers, Davey.

18th May 2005, 02:49 PM	#15
transducer diyAudio Member Join Date: Mar 2002 Location: Toronto, Canada	So it's pretty much a non issue. Thanks Davey. Cheers, Ron