Behringer DCX2496 digital X-over

Mod's on DCX2496

Hi Petter,

What I gather from your post is that your mod's (quite a list..) are aimed at:

- enhanced powersupply quality (noise, decoupling, ripple)
- DAC quality upgrade
- Clock quality / jitter situations
- Analog signal quality

In fact the only things that remain unchanged are the DSP processing part and the ADC's?! ;)


Maybe another option woud be (speaking being not too familiar with the matter however) to leave the thing as is and only bring out the (serial?) digital inputs/clocks to the DAC's (as SPDIF/AES-EBU?) and do an external set of DAC's with your spec power supply, opamps, condensators etc. ??
What about that? (RobM? :) )

Just a thought, got to have it running as it is now first.....

Henry.
 
Henry,

Your comments are almost completely correct. What is NOT changed is:

Input receiver
Sample Rate Converter
DSP chip
Control circuitry, display etc.

It is unlikely that the DAC chips are in fact receiving S/PDIF. They are more likely receiving BCLK, L/RCLK and SDATA (each). One of my first thoughts was to bring these out as you suggested. This is definitely a valid way to do things, particularly if you want the unit kept mostly stock, an dif you are able to move the clock out to the DAC chips as well (and feed it back to Behringer, and possibly even transport).

I should be getting mine tomorrow but I don't have anything to play with yet :(

How do you set your master volume???? I am planning to use Apox (www.dipchipelec.com)

Petter
 
SPDIF out DCX2496

Costs?

I have no idea.


Petter

For the moment I'll have to go with the analog inputs and accept the extra A/D conversion, feeding it from my Sony TA-E9000ES pre-amp.

After I have finished my active speaker project which I am currently working on, I am going to have a closer look at my transport/pre-amp. (Maybe also do a SPDIF-out on my preamp?......;) )

I had a look at the Apox site, good stuff!!

Henry.
 
SPDIF out on DCX2496

That was my idea as well Rob to maybe do this with some SPDIF encoder "paralel" to inputs to the internal DAC's
(Not sure if this was possible and how to do this though)

That was why I mentioned you ;)

This could indeed be an elegant way to use use some higher quality external (remote) DAC and analog circuitry while keeping the unit mostly original.

Henry
 
Costs:
DAC chips at $10-15 each. Need minimum of 3 for 6 channels. I am considering using 4 units (per 2 channels) (but need to verify that it works first.
Power supply mods, $10-300 depending on what you do and how "high end" you go with esoteric parts.
Op-amp replacement, anything from $.5 to $16 per unit -- you need at least 6 pieces.
Power line filtering, anything from zero (steal from old computer parts) to $60. You need one such unit.
Resistors, anything from $.5-$10 per unit (need up to 24 units).
Connectors: These are quite expensive -- can easily get to $10-20 per channel (need 6 ....). Then again, one can use what is already in there.
Clock upgrade -- can cost anywhere from near zero to commercial upgrades at hundreds of dollars. www.lcaudio.com is one such vendor. The highest end clocks are not typically available in the general market.

Most of the cost is your own time.

If you don't have access to PCB manufacturing, that could be troublesome as well. For me, cost there is essentially zero. For you, this might be troublesome. Also SMD work is painful.

Petter
 
quality

Hi folks, slow down, mods would be nice but the present quality is not bad at all. Today I just listen to one of my units and the sound -this is very preliminary-is very good.
Running along a Protools HD system that is regarded as "state of the art" in the profesional sound industry, the sound is Ok. We'll do more critical tests when we finish the Urei 809 mods.

Ric
 
You should be able to get quite far with $50
You should be able to do most of these things for $150-200 if you don't measure your time -- it is true that you need to know what you are doing. It should, however be possible to come up with a "cookbook approach", or at least a "how I did it" approach with some photos etc.

For me it is mostly for fun.

Petter
 
dcx2496

Ricren,

Good news! Keep us posted!

About the mods:
For me the discussion is a good "learning experience" - I will too use it as is for now and maybe do some "simple" :scratch: mods later...
By that time Petter will have it all figured out anyway .........;)

RobM

Sorry, I just closed the unit again.....otherwise I would have measured them for you....:(

If I look at the pictures though I see a lot of black wires and one single red one; could be that is + 12V(?) only (see also the regs(?) on the main board near the power connector)

I will do a measurement for you tomorrow.


Henry
 
One question for this thread

Hi,
I don't mean to start any trouble, but after reading this thread, I would like to know why would someone go through the costly and potentially harmfull process of upgrading the performance of a generic DSP box?
The algorithms available in it, IMHO don't justify the trouble. So, you'll get nice sounding converters and output stages, you still are very limited as far as crosover slopes go. With a lot of know how, good measuring/ loudspeaker CAD software and a lot of effort you might come close to the performance offered by a purpose designed analog crossover, be it of active or passive variety. So what your crossover's clock has low jitter, if the final product (the actual loudspeaker) has bad frequency response, poor phase tracking, serious lobing problems etc.
Anyone with enough knowledge and tools to make a good final product using the Behringer is capable of achieving the same or better results with 10% cost and 50% effort.
Just my opinion. YMMV.
 
my thoughts...

Hi,

my thoughts are to connect the behringer directly to the output of my cd player. and on the outputs of the behringer i will connect the amps.

i think it`s the money only worth, when stying digital from cd player until the amps!

But where to control volume?
Has anyone made soun experiences between passive crossover and behringer digital active crossover?

has someone idea how to connect spdif from cd player to aes/ebu of behringer?
is there anywhere a converter?

greets, Ralf
 
Re: One question for this thread

Thunau

Hi Jan,

It seems you know about the DSP software algorithms etc. used in the DCX2496, could you explain to us why you think they are not worth it?

Crossover slopes:

I think selectable crossover slopes from 6 to 24 db/Oct (Bes/But) and 48 dB/Oct (But.) are not too bad? :)

And that brings me to what I think is one of the biggest advantages of a dig-xover:

Flexibility!!!

Esprcialy for us DIY'ers the optimal solution to very easily change and experiment with a number of key parameters of an active loudspeaker system!

Henry.
 
SPDIF/AES-EBU

Hi Ralf,

The DCX2496 accepts SPDIF as well according to the manual.

If you want to stay digital "all the way" up to the (analog)amplifiers that is where you want to do the volume control IMO.

Promblem might be that you have to do this for all amps (In a 3-way stereo sytem this would require 6 (coupled) "devices" (eg, 6 conventional potentiometers)

See for a possible solution one of Petters posts in this thread, it has a link to a very interesting solution.


Henry.