Behringer DCX2496 digital X-over - Page 101

mige0 · 15th December 2006, 10:33 PM

Quote:

In my case, the DCX crackling was a bad ribbon cable inside
the DCX. If I open up the DCX and play music while touching
the cable, it would make aweful noise, this allowed to me to identify
which cable.

To fix this. I removed the ribbon cable and cut off the connector.
I re-crimped the same connector on the freshly cut end of the ribbon
cable. Problem never came back, it's fixed.

Had the same after many month of troublefree playing. Even putting something lightweight on the case caused crackling - very strong on slight movenmts of the cable itself. I pulled a little bit the ribbon cable that leads to the input and on that end it was sensitive and now its gone - moving the ribboncable as much as I like does no longer any harm!

Though its not your issue - Ryssen - I wanted to post it anyway.

greetings
Michael

Ryssen · 16th December 2006, 10:24 AM

Well here it says 139 Euro again http://www.selectronic.fr/dcx2496_fr.asp#04
Dont know what this is?My french is "nada"...

oettle · 20th December 2006, 06:51 AM

Hi Ryssen,

GND of your S/PDIF source should be connected to DCX GND (XLR pin 1). If your S/PDIF source is galvanically isolated (transformer) use a short! 110 ohm symmetrically cable with shield and connect both GNDs via shield.
Also driving capability of your S/PDIF source might be too low. Using a short cable (max 1m) you could change R15 on the DSP board from 110 ohm to about 200-500 ohm.

Greetings,
Frank

PS: By the way the 74HC02 mod works pretty well. Additional pull down (10k) on pin 28 (CS8420) and pull up on pin 3 is required (HW mode 5, serial output format OF2).

tnargs · 20th December 2006, 11:17 AM

Quote:

Originally posted by thylantyr
Identify if the cracking is mechanical or electrical.
In my case, the DCX crackling was a bad ribbon cable inside
the DCX. If I open up the DCX and play music while touching
the cable, it would make aweful noise, this allowed to me to identify
which cable.
To fix this. I removed the ribbon cable and cut off the connector.
I re-crimped the same connector on the freshly cut end of the ribbon
cable. Problem never came back, it's fixed.

This is not an uncommon issue, but it is not restricted to the DCX or indeed Behringer. I have 2 DCX's and they both had the same ribbon cable problem and Behringer paid for an independent repairer near me to fix them even though they were out of warranty. The repairer said many pro audio manufacturers now use ribbon to connect the main board to the I/O board, and they are causing problems. They said repair jobs are coming in just as much from more expensive brands; it is not price-related.

synergy · 20th December 2006, 12:32 PM

my apologies for a question that might already have been answered but i haven't been keeping up with this thread and simply don't have the time to sift through 101 pages (got to be one of the longest here surely?)

anyways i've recently installed a soundsystem in a bar using a DX2496 with the audio supplied by a soundblaster live card in their desktop pc

my original intention was to run this digitally but i'm having problems getting it to work

can anyone give me any tips?

does the digital input on the dcx work in the left/right & ground format (being as it's a 3 pin socket) or is it hot/cold & shield? (which are tied together?)

ie does the dcx have the capabilities to split the left/right components from a 'mono' signal?

as to the SB Live as far as i'm aware is one of the originals and as a result (according to the creative site) the digital out also doubles as center and sub outs and is therefore a 3 pole 3.5mm socket

i wired this all up as left/right & ground using a 5m mic cable (the amp rack is hidden away from idiots) but somewhere down the line i've made a mistake and it's not working

granted this is all stuff i should have thought about before the installation but could someone kindly point out the error of my ways?

ie is there anything i've missed in the setup on the pc (the dcx is self explanatory) or have i just wired it completely wrong in which case could i be shown the correct way please?

thanks in advance
Dave

Ryssen · 20th December 2006, 03:56 PM

Quote:

GND of your S/PDIF source should be connected to DCX GND (XLR pin 1). If your S/PDIF source is galvanically isolated (transformer) use a short! 110 ohm symmetrically cable with shield and connect both GNDs via shield.

As I have the DEQ2496 after the S/PDIF source (M-1000)connected as you describe,cable lenght 30cm.and the DCX2496 after the DEQ.I have a fully balanced XLR cabel between the to,30cm length.The DEQ can take the S/PDIF signal far above the red led,without distortion,the DEQ
can´t even take the half of it...I am going to do the Mode 5 thing when I get some spare time,and I´ve ordered a PCB for the Oelbach mod and maybee put a switch inbetween the 2.

oettle · 20th December 2006, 04:21 PM

Hi Ryssen,

I assume you don't have the problems using the analog inputs? Then the reason should be the S/PDIF input only.

The Oelbach mod and the 74HC02 mod adress quality of the digital input only but not crackling.

I assume your M-1000 has a RCA (cinch) connector for S/PDIF (consumer) output? So your source so far should be two ends of a tranformer coil, but not GND. You need to connect the shield of the cable to GND of your soure as well to connect GNDs of M1000 and DCX !!!

Try to replace R15 as well. With a 30 cm cable you can increase the 110 ohm value to reduce load of the source, so you'll get higher level.

Frank

Ryssen · 20th December 2006, 05:14 PM

Tryied analog in ,sounds as it should!By the way are you supossed to be able to change the input sens in digital in?Only works in analog mode.
This is M-1000 S/PDIF:

Should I Remove C56 and solder a wire ro ground?From the RCA the 30cm cable goes to a XLR with 1 and 3 grounded together,and the hot is pin 2.I have a 220 ohm resitor between ground and pin 2 as mentiod in many threds here.BTW I messaured 56 ohm when conected only to the M-1000.Between DEQ and DCX is a 30cm cable with XLR in the ends,one wire to each of the 3 pins.I´ve tried to ground 1 pin inthe cable between DEQ and DCX,no DIFFERENCE..

oettle · 20th December 2006, 06:18 PM

Hi Ryssen,

connect:

1. DCX XLR 1 with M1000 GND (D)
2. DCX XLR 2 with M1000 pin 2 (hot)
3. DCX XLR 3 with M1000 pin 1 (cold)

What is that 220 ohm resistor for? There is already a 110 ohm termination resistor on the DCX side.

Frank

AndrewT · 20th December 2006, 06:29 PM

Hi Ryssen,
r23=75r confirms that the digital out is looking for a 75r load. This is the standard loading for SPDIF.

The DCX2496 is set for an AES signal which is expecting 110r loading.

If the source and receive loads are matched then the reflections up & down the cable are minimised (precise matching=elimination).

If you intend using SPDIF as your sole source for DCX then reducing the DCX input resistor to 75r would make more sense.

or

add a switchable resistor (236r or 240r) in parallel to 110r to reduce the effective loading to 75r when SPDIF is the source.

Oettle,
why are you suggesting that the receive resistor be increased from 110r to >=200r, when this will increase the risk of digital data being misread due to excessive reflection of the signal.
Behringer claim that DCX will accept digital signals between 300mVpp and 10Vpp. SPDIF when loaded correctly will give well above the 300mVpp minimum.

16th December 2006, 10:24 AM	#1002
Ryssen diyAudio Member Join Date: Dec 2003 Location: Sweden--> Here	Well here it says 139 Euro again http://www.selectronic.fr/dcx2496_fr.asp#04 Dont know what this is?My french is "nada"... __________________ Regards Åke

20th December 2006, 12:32 PM	#1005
synergy diyAudio Member Join Date: Jan 2004 Location: here	SB Live! to DX2496 digitally? my apologies for a question that might already have been answered but i haven't been keeping up with this thread and simply don't have the time to sift through 101 pages (got to be one of the longest here surely?) anyways i've recently installed a soundsystem in a bar using a DX2496 with the audio supplied by a soundblaster live card in their desktop pc my original intention was to run this digitally but i'm having problems getting it to work can anyone give me any tips? does the digital input on the dcx work in the left/right & ground format (being as it's a 3 pin socket) or is it hot/cold & shield? (which are tied together?) ie does the dcx have the capabilities to split the left/right components from a 'mono' signal? as to the SB Live as far as i'm aware is one of the originals and as a result (according to the creative site) the digital out also doubles as center and sub outs and is therefore a 3 pole 3.5mm socket i wired this all up as left/right & ground using a 5m mic cable (the amp rack is hidden away from idiots) but somewhere down the line i've made a mistake and it's not working granted this is all stuff i should have thought about before the installation but could someone kindly point out the error of my ways? ie is there anything i've missed in the setup on the pc (the dcx is self explanatory) or have i just wired it completely wrong in which case could i be shown the correct way please? thanks in advance Dave __________________ think outside the box

20th December 2006, 05:14 PM	#1008
Ryssen diyAudio Member Join Date: Dec 2003 Location: Sweden--> Here	Tryied analog in ,sounds as it should!By the way are you supossed to be able to change the input sens in digital in?Only works in analog mode. This is M-1000 S/PDIF: Should I Remove C56 and solder a wire ro ground?From the RCA the 30cm cable goes to a XLR with 1 and 3 grounded together,and the hot is pin 2.I have a 220 ohm resitor between ground and pin 2 as mentiod in many threds here.BTW I messaured 56 ohm when conected only to the M-1000.Between DEQ and DCX is a 30cm cable with XLR in the ends,one wire to each of the 3 pins.I´ve tried to ground 1 pin inthe cable between DEQ and DCX,no DIFFERENCE.. __________________ Regards Åke

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20th December 2006, 06:51 AM	#1003
oettle diyAudio Member Join Date: Nov 2006	Hi Ryssen, GND of your S/PDIF source should be connected to DCX GND (XLR pin 1). If your S/PDIF source is galvanically isolated (transformer) use a short! 110 ohm symmetrically cable with shield and connect both GNDs via shield. Also driving capability of your S/PDIF source might be too low. Using a short cable (max 1m) you could change R15 on the DSP board from 110 ohm to about 200-500 ohm. Greetings, Frank PS: By the way the 74HC02 mod works pretty well. Additional pull down (10k) on pin 28 (CS8420) and pull up on pin 3 is required (HW mode 5, serial output format OF2).

20th December 2006, 04:21 PM	#1007
oettle diyAudio Member Join Date: Nov 2006	Hi Ryssen, I assume you don't have the problems using the analog inputs? Then the reason should be the S/PDIF input only. The Oelbach mod and the 74HC02 mod adress quality of the digital input only but not crackling. I assume your M-1000 has a RCA (cinch) connector for S/PDIF (consumer) output? So your source so far should be two ends of a tranformer coil, but not GND. You need to connect the shield of the cable to GND of your soure as well to connect GNDs of M1000 and DCX !!! Try to replace R15 as well. With a 30 cm cable you can increase the 110 ohm value to reduce load of the source, so you'll get higher level. Frank

20th December 2006, 06:18 PM	#1009
oettle diyAudio Member Join Date: Nov 2006	Hi Ryssen, connect: 1. DCX XLR 1 with M1000 GND (D) 2. DCX XLR 2 with M1000 pin 2 (hot) 3. DCX XLR 3 with M1000 pin 1 (cold) What is that 220 ohm resistor for? There is already a 110 ohm termination resistor on the DCX side. Frank

20th December 2006, 06:29 PM	#1010
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi Ryssen, r23=75r confirms that the digital out is looking for a 75r load. This is the standard loading for SPDIF. The DCX2496 is set for an AES signal which is expecting 110r loading. If the source and receive loads are matched then the reflections up & down the cable are minimised (precise matching=elimination). If you intend using SPDIF as your sole source for DCX then reducing the DCX input resistor to 75r would make more sense. or add a switchable resistor (236r or 240r) in parallel to 110r to reduce the effective loading to 75r when SPDIF is the source. Oettle, why are you suggesting that the receive resistor be increased from 110r to >=200r, when this will increase the risk of digital data being misread due to excessive reflection of the signal. Behringer claim that DCX will accept digital signals between 300mVpp and 10Vpp. SPDIF when loaded correctly will give well above the 300mVpp minimum.