First link failed for me, this works : The κDCX fully-differential analog board for Behringer DCX2496 and DCX2496LE
@johnnyjo
If you want to keep the outputs (and by extension the I/O board) as-is (prices in-EU, inc 21%VAT):
PSU upgrade - €197.19: DCX - Pwr.Supply
SRC/Clock upgrade - €91.81 kit, €152.31 prebuilt: DCX-SRC/Clock
DAC chip upgrade (stock AK4393 to improved AK4396). Pin-for-pin compatible ~$5 each @Digikey, 3 needed.
I can't speak to the improvements the above bring individually, since I began with Jan Didden's excellent €350.90 I/O upgrade then appended the above over several years and with incremental (but worthwhile) benefits.
Yes, the I/O mod does lower the output, but not as much as you might think. From spec sheet: Max output level (presumably output voltage with all digital bits used) is 5VRMS - ie between 4dBu 'pro' and -10dbV 'consumer' (actually closer to the pro level).
Unless you intend to upgrade(?) to some seriously inefficient speakers, I doubt this would be a problem - you'll likely need to trim amp gains down if running the DCX flat out.
NB the DCX2496LE has no digital in, or card slot (card slot used for IR on the I/O mod) - so may be unsuitable for some of the above - check first. DAC and PSU should be good for both models; SRC/Clock, and DAC upgrades both require SMD soldering.
Out of the box, the DCX sounds pretty ghastly; with the excellent mods above, it's pretty good.
If you want to keep the outputs (and by extension the I/O board) as-is (prices in-EU, inc 21%VAT):
PSU upgrade - €197.19: DCX - Pwr.Supply
SRC/Clock upgrade - €91.81 kit, €152.31 prebuilt: DCX-SRC/Clock
DAC chip upgrade (stock AK4393 to improved AK4396). Pin-for-pin compatible ~$5 each @Digikey, 3 needed.
I can't speak to the improvements the above bring individually, since I began with Jan Didden's excellent €350.90 I/O upgrade then appended the above over several years and with incremental (but worthwhile) benefits.
Yes, the I/O mod does lower the output, but not as much as you might think. From spec sheet: Max output level (presumably output voltage with all digital bits used) is 5VRMS - ie between 4dBu 'pro' and -10dbV 'consumer' (actually closer to the pro level).
Unless you intend to upgrade(?) to some seriously inefficient speakers, I doubt this would be a problem - you'll likely need to trim amp gains down if running the DCX flat out.
NB the DCX2496LE has no digital in, or card slot (card slot used for IR on the I/O mod) - so may be unsuitable for some of the above - check first. DAC and PSU should be good for both models; SRC/Clock, and DAC upgrades both require SMD soldering.
Out of the box, the DCX sounds pretty ghastly; with the excellent mods above, it's pretty good.
I use an M-Audio FastTrackPro for the USB to SPDIF conversion and run SPDIF through an impedance matching transformer to convert 75 ohm SPDIF to 110 ohm SPDIF into the A input of the DCX2496. Currently running as a stereo 2-way xover for my home stereo. Soon to be a 3-way xover as I improve my speakers. The only glitch is that I had to power the FastTrackPro from a wall wart so it won't pop when USB power is cycled during boot up and shutdown. The DCX has some pretty flexible EQ also.
\
Unfortunately, international shipping cost has been rising over the past few years and there is not much we could do about it.
I searched Digi-Key and Mouser, and the only 30MHz 3.3V 9x14mm oscillators are (apparently) the same Epson as used in the stock DCX2496. The datasheet contains no information about phase noise or jitter. Do you (or anyone) know of an available 3.3V oscillator in that size with specified (and good) phase noise and jitter performance?
I've used Fox Xpresso in quite a few DACs but it's smaller than 9x14. HC335R would be an upgrade?
FXO-HC335R-30 IDT, Integrated Device Technology Inc | Crystals, Oscillators, Resonators | DigiKey
FXO-HC335R-30 IDT, Integrated Device Technology Inc | Crystals, Oscillators, Resonators | DigiKey
Master clock upgrade
An easy but effective master clock upgrade for the DCX2496 and DCX2496LE:
The ο1 precision master clock
Specific application info on the DCX2496 is here:
ο1 installation into Behringer DCX2496
FYI.
An easy but effective master clock upgrade for the DCX2496 and DCX2496LE:
The ο1 precision master clock
Specific application info on the DCX2496 is here:
ο1 installation into Behringer DCX2496
FYI.
I'm thinking of using a DCX2496 (or LE) inside a motional feedback loop for a subwoofer. That means the processing time delay across the DCX2496 has to be a small fraction of a cycle for, say, a 100 Hz wave (10 milliseconds).
What is the shortest delay through the device when operating with a smallish processing load of EQ and other tasks? Under a millisecond?
Or any way you can help me see problems in this application.
BTW, odd there haven't been comments on the performance differences between the 2496 and the 2496LE?
Thanks.
Ben
What is the shortest delay through the device when operating with a smallish processing load of EQ and other tasks? Under a millisecond?
Or any way you can help me see problems in this application.
BTW, odd there haven't been comments on the performance differences between the 2496 and the 2496LE?
Thanks.
Ben
Last edited:
I dont agree. The feedback value is usually not the exursion
but the acceleration of the diaphragma witch copes with the air pressure. The speed of changing the acceleration is only limited by the inductance of the of the voice coil.
But yes the problem is a bit mor complicated then just pressing some knobs on a DCX.
https://media.music-group.com/media/PLM/data/docs/P0B6H/DCX2496_DCX2496LE_M_EN.pdf
Section 7, Specifications: "Signal delay: < 1 ms Analog input to analog output"
Section 7, Specifications: "Signal delay: < 1 ms Analog input to analog output"
Many thanks... and I am blushing for not looking first at the specs.
But "<1ms" is kind of vague as to how it is measured and possibly the sort of parameter that a manufacturer would be sort of casual about since it doesn't have a lot of significance for most ordinary feedforward installation.
Also, 1 ms is right on the border of what a feedback phase has to achieve even for a subwoofer, say 36 degrees... along with all the other phase gremlins in woofer speakers.
If I were not 3000 miles from my old DCX2496 and dual-trace oscilloscope, I might start answering this question myself.
Background: I'm preparing for an assault on motional feedback. I have an accelerometer, a dual voice coil driver, and a lot of experience with bridge circuit motional feedback too. Yesterday, in a flash of (false?) insight occurred to me that an easily adjusted DSP like the DCX2496 could solve a lot of problems in shaping and reshaping the feedback loop. IF fast enough.
Ben
Last edited:
I don't find that kind of bald authoritative-like pronouncement helpful in an DIY environment.
Could you explain your thinking?
BTW, 5-degrees is an ideal hardly appropriate in dealing with woofers where phase results are all over the map in the low freq range of greatest interest.
B.
Last edited:
I draw my conclusions from over a decade of experience.
I'm not saying you shouldn't try it, by all means go for it.
Also, to actively control the woofer, you will need adaptive processing to deal with the dynamic nature of moving masses and electromagnetic fields. I don't think the DCX had the ability to do that in the time frames required to produce a satisfactory result.
Again, try it for yourself.
If you succeed, please let us know and we all learn something new.
I'm not saying you shouldn't try it, by all means go for it.
Also, to actively control the woofer, you will need adaptive processing to deal with the dynamic nature of moving masses and electromagnetic fields. I don't think the DCX had the ability to do that in the time frames required to produce a satisfactory result.
Again, try it for yourself.
If you succeed, please let us know and we all learn something new.
Ben, good luck with your project.
The vendors (Same Day Music and Musician's Friend) provide PDF links for the Behringer manuals. Please note that when you look at the manual, there are two ways to set up the delays (Short delays and long delays). IIRC, to make matters more confusing, those two "types" of delays may actually be in separate menus. So it may take a bit of digging to get your answer
The vendors (Same Day Music and Musician's Friend) provide PDF links for the Behringer manuals. Please note that when you look at the manual, there are two ways to set up the delays (Short delays and long delays). IIRC, to make matters more confusing, those two "types" of delays may actually be in separate menus. So it may take a bit of digging to get your answer