Hi folks. I have dragged my dcx2496 system out of storage and want to build a 4ch attenuator. I have very limited funds - I'm wondering if 2 of these DACT copies would be suitable Dact Type SMD Stepped Attenuator 21 Step Free Ship | eBay . What would the best impedance be?
Thanks!
Thanks!
here's what I am going to try
The attenuators will work ,maybe you can insert one as in the schematic and try it!
Let me know if you give it a try,it might be a little longer before I get the time!
The attenuators will work ,maybe you can insert one as in the schematic and try it!
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well maybe,,,
IF you want a volume control and you want to stay balanced the schematic could work,IF you want a single out it will still work ,if you float the rca connector,in other words don't ground it to the case ,I use 3 nylon washers and a big hole in the chassis,2 big washers on the outsides and a small one on the inside ,like a sandwich,lol,but no chassis connection,to the rca connector.
I haven't tried that circuit out yet, but maybe soon ,let me know how it does,
I did listen to a friends rig and it worked fine,He also used caps to single end his output,sounded good,It was a 4 channel per side setup,with 2 dcx2496's.feed by 1 deq2496.
Good Luck!
NS
IF you want a volume control and you want to stay balanced the schematic could work,IF you want a single out it will still work ,if you float the rca connector,in other words don't ground it to the case ,I use 3 nylon washers and a big hole in the chassis,2 big washers on the outsides and a small one on the inside ,like a sandwich,lol,but no chassis connection,to the rca connector.
I haven't tried that circuit out yet, but maybe soon ,let me know how it does,
I did listen to a friends rig and it worked fine,He also used caps to single end his output,sounded good,It was a 4 channel per side setup,with 2 dcx2496's.feed by 1 deq2496.
Good Luck!
NS
Hello, this is my first post to diyAudio.
Inspired by the linuxworks mod in last December, I put a WM8805 digital output board in my DCX2496.
Actually I bought a WM8805 DAI board from the following, and configured with the pins.
????Blog
(sorry they only have Japanese page.)
A level shifter, 3.3V AVR and a transformer were put on the small additional board glued with the board.
http://www001.upp.so-net.ne.jp/home-dir/pic/dcx2496/01.JPG
http://www001.upp.so-net.ne.jp/home-dir/pic/dcx2496/02.JPG
Since R3 (100ohm to DAC SDATA) decreased signal amplitude and WM8805 didn't work, I removed it. The above picture was taken before the removal.
Sound quality improved very much!
Next mod is to put a SRC&Clock from Pilgham Audio. I'm looking forward to playing with it.
Hello,
I installed the SRC/Clock from Pilgham Audio to my DCX2496.
The result was fine! After the mod, the sound changed smooth and clear. The improvement was much more than I expected.
Then the next mod is to build a board for multi channel S/PDIF output. But before that, I need to learn EAGLE (PCB software) so it may take several months or longer.
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Just in case others have issues with cracking and dropouts on SPDIF on their DCX2496:
After being in storage for a few years mine developed an intermittent problem on the digital input. It would not start up and had pops and crackles on anything but 16/44 src. Turns out that the IDC crimp connection on the input board had a bad connection. Just touching the cable would trigger the dropout. I think this is also a common problem on the outputs. I removed the IDC crimp connector cover and peeled the cable out, reseated it firmly with a small screwdriver and replaced the connector top cover. So far it seems ok.
They really cut corners on the build quality to get the cost down. I would never put one of these into a PA system, it would have to be terribly unreliable.
After being in storage for a few years mine developed an intermittent problem on the digital input. It would not start up and had pops and crackles on anything but 16/44 src. Turns out that the IDC crimp connection on the input board had a bad connection. Just touching the cable would trigger the dropout. I think this is also a common problem on the outputs. I removed the IDC crimp connector cover and peeled the cable out, reseated it firmly with a small screwdriver and replaced the connector top cover. So far it seems ok.
They really cut corners on the build quality to get the cost down. I would never put one of these into a PA system, it would have to be terribly unreliable.
Do they make a USB model. My newest computer does not have a serial port like the old ones had.
Thx-RM
Well I have been putting of doing a volume control mod,Should have did this long ago ,so much ezier to set up the balance on the 8 different channels on 2 dcx's,I did basicly whats been posted I used a 10K pot and I jumped the mute and used the pins on the op amps pins1 and 6,I put a 1K resistor inline and a .001 cap across a 47 uf cap,I used some better 47uf caps ,I think the ones I removed were as old as the unit and cheep,LOL. I think some oc-cons for the digital section and maybe some new power supply caps,
Has anyone that replaced the power supply with a linear one care to comment?
Clocks seem to be a big inprovement also,
Thanks,
NS
Has anyone that replaced the power supply with a linear one care to comment?
Clocks seem to be a big inprovement also,
Thanks,
NS
hi Jan,
Did the power supply help the sound,was it a big change to replace it?
Thanks,
NS
Did the power supply help the sound,was it a big change to replace it?
Thanks,
NS
Did the power supply help the sound,was it a big change to replace it?
Thanks,
NS
That's a hard one to ask the designer
It's not dramatic, but for me it did change for the better.
Just personal opinion.
BTW Pilgham Audio, the guys I send those link for, told me there was a fire in the server room of their provider and they are now trying to rebuild there site. I think the pictures aren't rebuild yet as of Friday morning.
If you want info probably best to mail them.
jan
Thanks alot!
Hi Jan ,
I'll check that site out ,I know you made it but you probably would have scrapped it if it wasn't better than stock,Looks like a new design Too!
Thanks alot,
NS
That's a hard one to ask the designer
It's not dramatic, but for me it did change for the better.
Just personal opinion.
BTW Pilgham Audio, the guys I send those link for, told me there was a fire in the server room of their provider and they are now trying to rebuild there site. I think the pictures aren't rebuild yet as of Friday morning.
If you want info probably best to mail them.
jan
Hi Jan ,
I'll check that site out ,I know you made it but you probably would have scrapped it if it wasn't better than stock,Looks like a new design Too!
Thanks alot,
NS
Yeah the challenge was to manage space and heat dissipation for a linear regulator in that tight space.
At the end I selected an external wall-wart transformer (12VAC) that directly feeds the 5V, 3.3V and 6.2V regulators. A small, PCB-mounted custom 12VAC to 2 x 18VAC transformer drives the +/-15V regulators.
I even succeeded to re-use existing mounting holes in the box, so no drilling required!
jan
I have a duff Behringer dcx2496 could not find any one to repair it for so took the plunge & bought another used one with warranty OK . I want to go active with my Pheonix speaker . I have read many issues with it . You have got remember I am past my sell date so bear with me . The volume control I think is the main problem + others What do I really need to to overcome the issues please . I would need a lot info + help on this one .
Thanks Peter
Thanks Peter
hi all . abit off topic i am new in this forum been invited by no smoking . here is my 4 way analogue active cross over . i have tested it, it works and it is impressive.
i have used linkwitz 24db way all 4 channels have high pass and low pass filters the frequency division is in the schematic pls share your comments and experiences .
have fun
i have used linkwitz 24db way all 4 channels have high pass and low pass filters the frequency division is in the schematic pls share your comments and experiences .
have fun
Attachments
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gtG 4way with preamp 35h to 22k bom plain _ListByValues.pdf
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gtG 4way with preamp 35h to 22k plain pcb artwork.pdf
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gtG 4way with preamp 35h to 22k plain schematic.pdf
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gtG 4way with preamp 35h to 22k plain schematic 1.jpg -
gtG 4way with preamp 35h to 22k plain schematic 2.jpg -
gtG 4way with preamp 35h to 22k plain.jpg
Hi Stewin,
Looks good , Could you post the silk or a stuffing guide?
Power supply is + - 12volts,what transformer did you use?
I will start them soon ! Thanks for posting!
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