DCX2496 Mods

mgalusha · « **Reply #20 on:** 21 Jan 2008, 03:30 pm »

Well it was time to break out the iron again yesterday and do some more work to the DCX. In early December I contacted Frank Oettle in Germany about the improved input module he had designed for the DCX. This lovely little board replaces not only the input receiver/sample rate converter chip but also provides an extremely good low jitter (2.5ps) clock. It has it's own dual regulators to provide exceptionally clean power for the clock and and SRC chip. It arrived a couple of weeks ago but I haven't had a chance to get this installed until now.

Frank's main post about this can be found here: http://www.diyaudio.com/forums/showthread.php?postid=1376217#post1376217 though it was mentioned several pages earlier, this was more of a formal announcement. The folks on diyAudio that have installed it have nothing but praise for the results. I must add my voice to the chorus, the results are excellent.

Improvements that I'm hearing are greater clarity in the high frequencies. Extremely clear and detailed but without being shrill or harsh. The midrange has both greater clarity and richer harmonics and sound stage depth has increased as well. I wasn't expecting much change in the bass but it seems better defined, not deeper or stronger, just with better definition especially on the upright bass. The music also seems to float free of the speakers more that before. I'm very happy with the results.

Frank is no longer offering this but Ward Maas of Pilgham Audio (www.pilghamaudio.com) will soon have these available. Ward is the person distributing Jan Didden's active analog kit so you can do one stop shopping for some truly excellent DCX mod parts.

If you are considering this mod and you don't have some experience working with SMD's get an old circuit board and practice. I highly recommend getting a starter kit of Chip Quik (http://www.chipquik.com). This is a surface mount rework product that uses a very low temperature alloy to allow removal of the chips without damage to the board. The DCX board is VERY fragile in this regard and removing the chips without either a hot air rework system or something like Chip Quik is flirting with disaster. Chip Quik allows the chips to be removed with a standard iron at about 150* F, much below the point where the adhesive holding the pads to the board fails. I've done several boards with this and the results have been excellent. The Chip Quik site has some "newsletters" that contain some very good information about SMD rework.

Bottom line on the new mods is two thumbs way up. I am delighted with the results and the combination of Jan's kit and Frank's board (and also his regulators) is very very good.

I know that lots of folks are using the DCX with the Emerald Physics CS2's and while I'm not the benefits are the same. I know TomS and Zybar are using DCX's with Jan's board in them and I know both are thrilled.

I'm using the DCX to drive a Rotel 1080 on the bottom and R.E. Designs LNPA's on the top. My speakers are Meadowlark Blue Heron 2's. The woofers are Scan Speak 8545's, in this case from Northcreek Music (before they stopped selling drivers) and have double magnets. Mids are Scan Speak 12M/4631G Revalator's and the tweeters are the Scan Speak R7904/7000 ring radiator. The woofers are of course directly connected to the amp, no LP crossover other than the DCX, the mids/tweets are still using the original passive XO though the HP caps to the mids have been removed. The tweeter circuit uses an Obligato cap bypassed with a .1uF Sonicap Platinum and a .01uF Mundorf supreme silver/gold. This seems a splendid combination. The bottom of the cabinets have been filled with about 50lbs of lead shot (fully sealed, no health risk) and the woofers and mids have some felt added on the back to absorb some of the back wave reflections. Source is an excessively modified Squeezebox 2.

Mike

TomS · « **Reply #21 on:** 21 Jan 2008, 10:56 pm »

Mike,

Glad to hear Frank's clock/ps mods worked out well. That install looks a little hairy, but I'm going to try it anyway

. I'm on the list with Ward already.

Did you also put in the 5v mini regulators?

The ChipQuik SMD kit looks really nice - great find. Did you get the full blown one that's about $100 or the "basic" that is $20? Since they apparently don't sell direct, I tried Circuit Specialists. They just had the basic kit but not the other in stock right now.

Tom

mgalusha · « **Reply #22 on:** 22 Jan 2008, 12:08 am »

Tom,

Yes, I used two of Frank's mini regulators, very nice. Stepahne at AWDIY.com also has some mini regulators. I don't think they are quite up to the level of Frank's but if one is putting in a linear supply they look to be a great match as Frank's will kill some of the HF noise from the switcher which of course the linear PS won't have.

DigiKey sells the Chip Quik products as well. The SMD-1 kit is what I picked up and DigiKey had it for $13. Since I was ordering some other parts it was an easy choice. I also ordered an extra tube of their tacky flux. Works very well for putting on new chips as it tends to hold them in place until you can get a pin or two soldered.

PM or call me if you have any questions about installing the SRC board.

Mike

Brian Cheney · « **Reply #23 on:** 22 Jan 2008, 02:08 am »

We'd like to offer these DCX 2496 upgrades to our customers as well. Anyone doing them commercially?

B Cheney
Pres VMPS Audio
www.vmpsaudio.com

nicksgem10s · « **Reply #24 on:** 22 Jan 2008, 03:30 am »

Hi Mike,

Does the Didden kit provide the option for remote volume control?

Luckily I have a buddy who is skilled with mods that is going to be building the kit for me along with some other upgrades. Thanks to you for being an early adopter and reporting on your results. Your original post set me off on this path.

Thanks to Mr. Didden for building what I am envisioning as an excellent sounding upgraded kit.

I appreciate all the help my fellow AC members provide.

Your guys are great!

-Nick

TomS · « **Reply #25 on:** 22 Jan 2008, 03:41 am »

Nick - yes it does provide remote capability standard. You supply a cheapo remote controller. See my post on the other thread. Tom

mgalusha · « **Reply #26 on:** 22 Jan 2008, 01:28 pm »

Quote from: Brian Cheney on 22 Jan 2008, 02:08 am

We'd like to offer these DCX 2496 upgrades to our customers as well. Anyone doing them commercially?

Brian,

I don't know of anyone yet but I suspect that someone will as not everyone likes the DIY approach. I suggest contacting Ward Maas at Pilgham Audio and see if he and Jan know of anyone who will be offering these commercially.

Mike

konut · « **Reply #27 on:** 22 Jan 2008, 02:44 pm »

Long time AudioCircle member Ric Schultz indicates he will be offering mods for the DCX in the future. http://www.tweakaudio.com/EVS-2/Whats_New.html

Occam · « **Reply #28 on:** 22 Jan 2008, 03:40 pm »

Folks,

Discussions of commercial mods/products (even in vaporware status) in the Lab is fine, as long as -
1. It is an 'open' mod, discussed or documented here or elsewhere like those discussed at DiyAudio.
2. And/Or is a diy kit

Otherwise, it belongs in Industry Ads/Discussions or a specific vendor circle.

TIA,
Paul, Facilitator of the Lab Circle

EDIT Let me clarify a bit.... my post was specifically aimed at konut's post. I wasn't specific as konut was just trying to help, nor did I want to appear to be judging Ric Shultz's mods in any way. All the mods mentioned previously are documenting extensively on diyaudio (hence 'open' source) and/or are diy kits which clearly fall within the mandate of the Lab. Ric's mods are proprietary and also not diy, so mention of them isn't appropriate for the Lab. Yeah, I know I'm being overzealous, but you've got to draw the line arbitrarily somewhere, lest the next thing you know, men will be marrying ducks and women, dolphins.

richidoo · « **Reply #29 on:** 23 Jan 2008, 02:13 am »

Ditto what Nick said. We're all following in your wake Mike, so please stay off the rocks - haha

My active DCX kit is on the way. Looking at PS and clock as soon as Ward is ready. Thanks for the Chip removal tip.
Rich

mgalusha · « **Reply #30 on:** 23 Jan 2008, 03:47 am »

Quote from: Occam on 22 Jan 2008, 03:40 pm

Yeah, I know I'm being overzealous, but you've got to draw the line arbitrarily somewhere, lest the next thing you know, men will be marrying ducks and women, dolphins.

You mean I can't have I can't have all three? Damn what's the world coming to?

mgalusha · « **Reply #31 on:** 23 Jan 2008, 03:48 am »

Quote from: richidoo on 23 Jan 2008, 02:13 am

so please stay off the rocks - haha

No worries, I like my Scotch neat, no rocks.

jtwrace · « **Reply #32 on:** 20 May 2011, 08:55 pm »

WOW!

Not an inexpensive kit http://www.pilghamaudio.com/index.php?page=dcx-active-upg

Bob in St. Louis · « **Reply #33 on:** 21 May 2011, 02:01 am »

Quote from: jtwrace on 20 May 2011, 08:55 pm

WOW!

Not an inexpensive kit http://www.pilghamaudio.com/index.php?page=dcx-active-upg

About $410 US?

Not "too" bad, imho.....

Bob

gongos · « **Reply #34 on:** 21 May 2011, 03:32 am »

Quote from: konut on 22 Jan 2008, 02:44 pm

Long time AudioCircle member Ric Schultz indicates he will be offering mods for the DCX in the future. http://www.tweakaudio.com/EVS-2/Whats_New.html

Tried for over a year to get the EVS mod done to a 2496--never had any luck.

mgalusha · « **Reply #35 on:** 21 May 2011, 01:58 pm »

Quote from: Bob in St. Louis on 21 May 2011, 02:01 am

About $410 US?

Not "too" bad, imho.....

Bob

At the time the dollar was not doing well vs the Eruo and it was more like $600 IIRC. Given that the DCX is less than $300 it was a lot of $$ to spend on the kit but no regrets, my little box still sounds pretty good and works very well for the subs.

zybar · « **Reply #36 on:** 21 May 2011, 02:40 pm »

Quote from: Bob in St. Louis on 21 May 2011, 02:01 am

About $410 US?

Not "too" bad, imho.....

Bob

And well worth it. I have no problems recommending the kit.

George

jackman · « **Reply #37 on:** 21 May 2011, 03:49 pm »

Quote from: zybar on 21 May 2011, 02:40 pm

And well worth it. I have no problems recommending the kit.

George

I wish I was handy with the soldering iron. That's a very good price when you consider the performance upgrade.

richidoo · « **Reply #38 on:** 21 May 2011, 04:39 pm »

I'm happy with mine too, the kit was not too difficult to assemble, with a little help from friends.

Good sound, and remote control volume! Jan gave me fast help by email a couple times too.

The only problem I have is the digital input receiver chip that Behringer used is a known defective part. Pilgham has an upgrade kit to replace it. Did any of you guys install the SRC/Clock upgrade from Pilgham? Sound improvement? Easy to install? My DCX has intermittent dropouts until I fix that input chip. It started to go bad just this year after a year of working fine.

Another option for the DCX is a transformer output, like Gary Pimm did.
http://www.pimmlabs.com/web/behringer.htm
But you still need to replace the input chip eventually. And the power supply caps eventually.
Rich

joelau_hk · « **Reply #39 on:** 28 Jun 2012, 09:16 pm »

Does anyone have experience compare MINIdsp vs DCX2496 ?