Behringer DCX2496 digital X-over

[AnthonyPT]

Hi

The Silicon Chip K5600 6 channel remote volume control
is still on special at Altronics with a rack
mount case. Specs look fairly good. I bought
one and will update the TL072s when I get round
to assembling it. Have not got the cash for the
DCX yet but will have to attenuate the DCX outputs
which I hope will not be an issue.

Regards

AnthonyPT

http://www.altronics.com.au/index.as...=item&id=K5600

[jan.didden]

Originally posted by AnthonyPT
Hi

The Silicon Chip K5600 6 channel remote volume control
is still on special at Altronics with a rack
mount case. Specs look fairly good. I bought
one and will update the TL072s when I get round
to assembling it. Have not got the cash for the
DCX yet but will have to attenuate the DCX outputs
which I hope will not be an issue.

Regards

AnthonyPT

http://www.altronics.com.au/index.as...=item&id=K5600

Anthony,

That is an interesting unit! Is that price in Aussi dollars?
Do you have any info on how it works, solid state vca or mechanical pots?

Jan Didden

[AnthonyPT]

Hi

It uses a pic controller and LM1973s plus
Tl072 buffers. PDFs of the boards are available besides the kits
Also the Pic code is available.
That price is AUD$150 for the whole kit at present.

Regards

AnthonyPT

http://www.siliconchip.com.au/cms/A_...ntArticle.html

[ergo]

BTW, where can the AK4395 DAC chips be ordered (preferably shipping to EU)?

I might try the DAC upgrade at some point assuming I can order them somewhere.

Ergo

[jan.didden]

Thanks Anthony,

I just downloaded the article part 1. Nice! This may not be the most-fi unit available but for that price it may help me to get into multichannel-issues while developing my own 6 channel control. I have to see if they will ship to Europe.

Jan Didden

[Padel]

Originally posted by akunec
Yes, it's source->preamp(analog)->DCX->Chipamps

All rca <-> xlr connectors are soldered from the center pin to pin 2, and pin 1 to shield.

Hi,

Remove the Pin1 to Pin3 connections (links) at the inputs and outputs and see if it helps.

Regards
Padel

[sendler]

Originally posted by ergo
sendler,

Is the AK4395 a full drop in replacement or did you have to change something besides the chips also?
.
I just dropped mine in. I haven't had anyone hack the controler code so so I'm not sure which control register defaults may be different between the two but the AK4395 sounds great in my DCX. It has even better see through transparancy and the improvement in the bass is unbelievable! It adds another octave of extension with greater slam and speed.

Did you do the simple RC out before the change of DAC IC's or after? If after then what were the most obvious changes in sound that made it better?
.
I swapped one dac before switching to the direct out mod. At that time I was running the output in what could be called the stage 2 mod, with c43 bypassed with a .01 Dayton foil cap and the signal tapped off of the output of ic1b pin 7. See above for the changes in the sonics. The improvements were the same with the active out and then later, the direct out.

I have ran the DCX with simple RC also for quite long but as I need a volume after DCX and I have different amps (one 4 channel and one 2 channel) I had problems with the arrangement. Somehow the sound is not as good if a passive volume is inside the DCX and there is no active stage after it. And it is not just in highs. The mid and bass also lack freedom and livelyness.
.
You and I have already discussed this. Passive volume controls sound much better when positioned at, or in, the amp. It is a little less convienient when changing volumes but the price/state of the art performance is worth it if the highest sound quality takes precedence.

So this is why I'm working on a version where I will use RC followed by 6 channel 10k ohm pot and followed by opamp to get some gain and to buffer the output.
.
Sounds like a plan. I like the Linear Technology LT1360 opamp.
Or, you could even use the ic1b that is already in the DCX to start out with as those opamps are really not that bad.

It also makes it possible to have different gains in analog stage for different channels and I do not have to sacrifice so much DAC resolution in tweeter channels.
.
Keeping the digital attenuation minimal. Good plan.
.
Check here for your regional distributor for the 4395 chips.
Ask for some free samples.
http://www.asahi-kasei.co.jp/akm/en/...a/euro_sr.html
.
When my supplier is back in stock in 6 weeks, I will buy a tray of 50 to resell for those of you that want to try the dac upgrade.
World wide shipping has turned out to be pretty reasonable via USPS costing only $20 to $25 to ship my attenuators anywhere in the world. My only hesitation to buying 50 chips is the fear that Behringer is doing a redisign of the DCX and SRC that would leave me stuck with them at $7 each but Behringer says that the DCX is still a current product and is just out of stock.

Scott

Ergo

[Davey]

Originally posted by janneman
Thanks Anthony,

I just downloaded the article part 1. Nice! This may not be the most-fi unit available but for that price it may help me to get into multichannel-issues while developing my own 6 channel control. I have to see if they will ship to Europe.

Jan Didden

Jan,

All the info/schematics are available on the DCX forum. Look at the top of the files section. It's been there for awhile.

http://groups.yahoo.com/group/DCX2496/

Davey.

[mpmarino]

Greetings,
I think I've been thru most of the info here and on the Yahoo grps page. I'm still in a quandray. I'm looking at the DCX2496 or the 3400(?) 3 way analog. Due to how my system will be laid out I MUST use the analog in and control volume BEFORE the X-over.

My pre will be a Bosoz (I think I can get some good levels out) and the 2 hi-pass amps will be aleph. My situation is that I need some solid opinions (surprise). Do you guys think that the front-end level issue can be overcome to equal the quality I will get with the analog unit, condidering the flexibility of the DCX. I am willing to do some careful level matching..In other words, 'Is it really THAT bad or is post attenuation just a bit better'? I know how tough a question this is. I am willing to do some mods to the DCX. The time alignment will be very useful to me and my setup, but not if it 'really' sounds like DOG. The WAF makes it tough to make purchasing mistakes and I want to be as sure as I can be before plunking the cash down.

Sorry to be a pain in the a~~!
Marc

[Davey]

Marc,

It's not a pain-in-the-..........it's actually the basic question that most users have with the DCX...for home use.

You could add fixed attenuators to the six outputs of the DCX and it will work fine for your configuration. Many DIY-audiophiles (myself included) tend to get a little obsessed with wringing the last bit of "performance" out of a piece of gear, but in the case of the DCX it's really not necessary....it's pretty darn good stock (used correctly.) You really don't need to mod it.

If you're using XLR/RCA adaptors on the outputs break the internal pin 1-3 connection on those. That will shift the internal levels of the DCX higher by 6db. If you want to take it farther you can add some external fixed-resistor attenuators to reduce the level a bit more....maybe 6db. That's an additional 12db voltage gain your preamp would have to provide, and that's assuming that you don't have lowish gain power amps and lowish efficiency speakers that would have already forced the internal levels too high.

Cheers,

Davey.