Behringer DCX2496 digital X-over

[Studley]

AK4396

Anybody know a source for these DACs?

Also, what would be a fair price to pay for them?

 

[VT67]

I bought mine from this guy:

http://www.diyaudio.com/forums/showthread.php?threadid=131661&highlight=

Regards

 

[kepa1]

Replacement XLR/RCA connectors

Hello,

I know some Neutrik "PCB style" connetor fit in the DCX chassis but I'm looking for "solder pin type" to go along with transformers, both RCA and XLR (and even BNC for the digital input!). The Neutrik ones are too big, unfortunately.

Did someone identify any brand that sells them?

Thank you

 

[jakobsladderz]

Off topic by two letters but no probs ... On the DEQ2496 the Aux and Digital outputs are the same feed (DSP output channel) so the aux cannot be delayed with respect to the digital and vice versa. You can however choose to delay either the main or auxiliary/digital outputs so hook your subs up to the analogue main outputs (XLR) and then hook the digital out to your mid-high's and all should be well. if you need balanced analogue for the mains also, that's no prob as the auxiliary output is balanced too..

If you really want those plugs on the back and are not too shabby on the tiny electronics involved you may be able to swap the I2S lines (digital audio signal) from the D-A converters over (I guess alternatively swap the analogue outs from the D-A chips) to get the main DSP feed out of the aux connectors and vice versa.

Duncan

 

[Real_Macgyver]

How does it perform? Nice chip with AD DSP and AKM A/D D/A.

To bad the PCB layout is among the worst I have ever seen.

 

[audio_roo]

At home I use a Behringer Eurorack to mix the input to my DCX. On the DCX output I had a pair of home-boxed Hypex Class-D 400w/c amps driving my JBL speakers.. Unfortunately last week a power surge seems to have blown my Hypex amps (yes, I should have used a surge protector but lost it in a recent house move!). The up-shot is 500Euro worth of Hypex amps is now dead. So I replaced them with a Behringer EP 4000. I know it's not the ideal system, but it does the trick and is very flexible.

THE CURRENT PROBLEM is that when the Hypex amps blew, they seem to have destroyed output channel 2 of my DCX when they output 40V dc across their input terminals at failure. Great. I'm pissed about only having 5 channels left on the DCX. As the other 5 DCX output chans still work great, I wanna fix the 6th and keep full flexibility of the DCX.. I think it's probably a simple as a last-stage back-protective IC that has blown..

Anyone got experience with the final output stage, or it's repair? looks like very simple/repairable circuitry, and schematics seem to be available.. does anyone have any tips??

I think getting the thing posted back for Behringer repair will cost more than a replacement unit (I think it may be out of its warranty period, lost all the details ).

Any help here?

Cheers,
Andrew

 

[DorinD]

Off topic by two letters but no probs ... On the DEQ2496 the Aux and Digital outputs are the same feed (DSP output channel) so the aux cannot be delayed with respect to the digital and vice versa. You can however choose to delay either the main or auxiliary/digital outputs so hook your subs up to the analogue main outputs (XLR) and then hook the digital out to your mid-high's and all should be well. if you need balanced analogue for the mains also, that's no prob as the auxiliary output is balanced too..

If you really want those plugs on the back and are not too shabby on the tiny electronics involved you may be able to swap the I2S lines (digital audio signal) from the D-A converters over (I guess alternatively swap the analogue outs from the D-A chips) to get the main DSP feed out of the aux connectors and vice versa.

Duncan

Thank alot for the information!
Dorin

 

[Liliya]

CS 8420 outputs

I need some help to locate were this outputs from CS 8420
"ends" up on the main board on my DCX 2496:

Pin 16 OSCLK go to UBCLK
Pin 17 OLRCK go to ULRCLK
Pin 21 OMCK go to CLK 24
Pin 09 RST go to HRST

I need to know where I can find "good" soldering points for a flat-cable for UBCLK, ULRCLK, CLK 24 and HRST.

Forget pins or soldering pads on the main board. They are all (mostly) gone.

A disaster, but I shall not bore anyone about how this could happens.
With a new input stage I hope I can "rescue" the the main board.

Regards

E. Stillingen

 

[SQLGuy]

At home I use a Behringer Eurorack to mix the input to my DCX. On the DCX output I had a pair of home-boxed Hypex Class-D 400w/c amps driving my JBL speakers.. Unfortunately last week a power surge seems to have blown my Hypex amps (yes, I should have used a surge protector but lost it in a recent house move!). The up-shot is 500Euro worth of Hypex amps is now dead. So I replaced them with a Behringer EP 4000. I know it's not the ideal system, but it does the trick and is very flexible.

THE CURRENT PROBLEM is that when the Hypex amps blew, they seem to have destroyed output channel 2 of my DCX when they output 40V dc across their input terminals at failure. Great. I'm pissed about only having 5 channels left on the DCX. As the other 5 DCX output chans still work great, I wanna fix the 6th and keep full flexibility of the DCX.. I think it's probably a simple as a last-stage back-protective IC that has blown..

Anyone got experience with the final output stage, or it's repair? looks like very simple/repairable circuitry, and schematics seem to be available.. does anyone have any tips??

I think getting the thing posted back for Behringer repair will cost more than a replacement unit (I think it may be out of its warranty period, lost all the details ).

Any help here?

Cheers,
Andrew

Don't know if you fixed this yet. Best thing would be to have a scope. Second choice would be a patch cable running into an an amp and speaker so you can test for signal. Basically, ground the shield of the cable to the ground of the DCX, and use the center pin as a test proble. You can calibrate the volume by first "probing" a working channel.

The thing to check for is where the signal is lost. I doubt more than the last 4580 got blown, but it's better to know for sure. If you have signal at pin 7 of IC2, then the problem is definitely in the last 4580 (IC13), or it's supporting resistors. You can also check for signal at pins 7 and 1 of IC13 to see whether one of the 60.4Ohm resistors is blown. If you have signal at pin 7 of IC2 but not at BOTH pins 7 and 1 of IC13, then IC13 is the main problem and will need to be replaced.

How are you with surface mount soldering?

 

[SQLGuy]

It may depend on the chip, but that is usually what they are spec'd for. I've asked tech support if they found a better operating point, but they said no - 1K was it.

That said, I've run them from 600R to 50K. They didn't seem to have a problem at all. But if you are using a transformer, it's not going to be a linear load unless you put a swamping resistor across it.

But please, feel free to experiment with different loads. It's easy enough to do! Somewhere between 1K and 3K has worked best for me. YMMV.

Guys, it's right here in the data sheet (http://www.asahi-kasei.co.jp/akm/en/product/ak4396/ak4396_f00e.pdf - page 10): minimum AC load resistance = 1K Ohm.

If you're loading these things with 600 Ohm loads directly, you're overloading them.

 

[AndrewT]

what if there is a little parasitic capacitance in parallel with the 1k0 minimum load?

Should we increase the resistive part of the load to ensure the maximum current never exceeds a set limit?

 

[AR2]

Guys, it's right here in the data sheet (http://www.asahi-kasei.co.jp/akm/en/product/ak4396/ak4396_f00e.pdf - page 10): minimum AC load resistance = 1K Ohm.

If you're loading these things with 600 Ohm loads directly, you're overloading them.

I questioned this subject a lot, and this is what I found: You might be correct regarding the impedance of the transformer itself, only if you have transformer only connected and nothing behind it, which is never the case. But the unit that gets connected after the transformer will reflect its impedance as the load to the DAC in the reverse proportion of the transformer's ratio.

The question of line transformer's impedance I always find sort of mysterious. I spoke with Mr. Lundahl itself and many other experts on the subject that encouraged me to safely proceed with the transformer mod. Never had the problem - far from it. Not being an expert and not fully understanding the subject, I avoided placing the volume control right after the transformer, but after the preamp, between the preamp and amp, where XBOSOZ preamp allows for that. That way I have full preamp impedance loading through the transformer to the DAC.

I would love to have someone more knowledgeable than myself (not hard to find) elaborate on the subject here. Jan Diden feel free to correct me.

 

[DorinD]

A brand new idea!

Hello guys,

I'm thinking just discover a new way to interface DCX2496 to high sensitivity drivers! It needs to be verified in practice but for the moment I don't see any inconvenient.

For example I'm using -20 and -30dB attenuation pads to attack the power amplifiers. Amp's volume controls are about -17dB and also have -9dB attenuation into a DCX. So, the total attenuation for normal listening level is about -50dB. Isn't craizy?!

Just imagine if I am connecting my mid/hi drivers using an 70/100V transformer directly to the DCX output, something like this:

http://www.monacor.de/typo3/index.php?id=62&L=1&act=8&act_sub=21&artid=280&spr=EN&typ=u

and with one shot I solve the attenuation and impedance mismatch between DCX and drivers. In theory, DCX has an max voltage excursiun of +/-10V over a minimum 160 ohm load and a couple hundreds mW can be sucked from it. Just enough to drive my 9xdB/1w/1m compresion drivers in my dining-room.

I was wondering if this could work also for the midbass horns? The corresponding poweramp's 1W LED never clips, so I am even with this in mW power range.

 

[Brett]

Re: A brand new idea!

Hello guys,

I'm thinking just discover a new way to interface DCX2496 to high sensitivity drivers! It needs to be verified in practice but for the moment I don't see any inconvenient.

........

I was wondering if this could work also for the midbass horns? The corresponding poweramp's 1W LED never clips, so I am even with this in mW power range.

You are using a 4580 to power the speaker via transformer? And you don't see a problem with it?

Because you don't see the 1W LED going on doesn't mean transient power requirements aren't a good deal higher.




http://www.cordellaudio.com/rmaf/workshop5.shtml

 

[DorinD]

Brett, I was reading somewhere that a guy listen to his high-sensivity loudspeakers simply conected to DCX's output and have pretty decent level. This means he didn't even adapt impedances and those 4580's see 4 ohm or less.

In fact there are two 4580's per output and each one can provide some hundreds mW. Personally I will give it a try and buy a transformer (8 euros a piece).

 

[DorinD]

Whay about this?

If the method works I could use this in my rack:

http://www.monacor.de/typo3/index.php?id=62&L=1&act=8&act_sub=21&artid=1&spr=EN&typ=u

at about 200 euros.

 

[kepa1]

Please do Dorin and report the results!
I've been using the direct output of the DCX to drive high efficiency tweeters (even 4 ohms ones) or CD crossed at 3k and am satisfied with the sound (I'm always far from the max output).

This sounds completely technical non sense but believe me it works.

 

[DorinD]

I've made some calculus and find this:

- for a 5W trafo the DCX output will see 2k impedance and I could get max 50mW@4ohm power for 10Vef excursion.
- for 10W trafo --> 1k impedance and max 100mW@4ohm max power
- for 20W trafo --> 500 ohm impedance and 200mW@4ohm max power

So, with 200mW@4ohm into a 96 tweeter I'll get pretty high acoustic power level. The problem is what trafo to choose considering existing drivers and needed acoustic level. A 10W rated trafo seems to be a good compromise beetween decent load for output and enough power for driver.

 

[DorinD]

I'm feeling like doing a "first watt" conversion of the DCX2496 (Forgive me, Nelson!)

 

[SQLGuy]

Brett, I was reading somewhere that a guy listen to his high-sensivity loudspeakers simply conected to DCX's output and have pretty decent level. This means he didn't even adapt impedances and those 4580's see 4 ohm or less.

In fact there are two 4580's per output and each one can provide some hundreds mW. Personally I will give it a try and buy a transformer (8 euros a piece).

This has to be bogus. The 4580's have 60.4 Ohm 1/10W resistors in series with their outputs. As such, the 4580's, directly connected to 4 Ohm speakers, couldn't provide more than about 15mW into the speaker.