Modify Behringer DEQ2496?

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#61
15V linear PSU added to the DEQ to serve the op-amps in replacement of the original PSU.

alim_DEQ15V2.jpg


4 cables to cut and it's ready. Large difference show on the scope.
 
#64
ryssen said:
Do you have a schema of your mod?
Click to expand...

Not realy but it's not difficult.

First build a small 15V PSU using LM317 and LM337. I use a 2x15V 15VA toroid. Fix it a the best place depending of the PSU size. Be sure to isolate the LMxxx and the PCB from the DEQ box. You will not need a large cooler for the LMxxx.

On the power cable cut the first RED cable (+15V), the second black cable (-15V), the fourth black cable (analog GND). Connect the + and - 15V from the DSP board to the new PSU. Connect the new PSU GND to the GND cable coming from the old PSU and the GND cable going to the DSP board.

That's all.

With the new PSU, you reduce the noice by x10, have less heat on the old PSU, and more power for the analog and digital circuits.

alim_DEQ15V.jpg
 
#67
I opened up my DEQ2496 just to look. I am surprised to see a DSP board that doesn't have a ground plane. The decoupling on this PCB is terrible. I wondered why I had an occasional lockup where I had to power off and back on. Now I know!

I had some tantalum caps laying around and I soldered them near the SHARC chips. Right on top of the small ceramic caps.

I may add some more capacitance in the power supply cable instead of modding in a new power supply. (I'm using digital in and out, not the analog outs)
 
#70
rossl said:
I opened up my DEQ2496 just to look. I am surprised to see a DSP board that doesn't have a ground plane. The decoupling on this PCB is terrible. I wondered why I had an occasional lockup where I had to power off and back on. Now I know!

I had some tantalum caps laying around and I soldered them near the SHARC chips. Right on top of the small ceramic caps.

I may add some more capacitance in the power supply cable instead of modding in a new power supply. (I'm using digital in and out, not the analog outs)
Click to expand...

Your power problem comes from a bad contact on the power connector (quality of the contact inside). I add the same problem. Check the 5V pins first.

Coupling caps are ok on the DSP board but I you want to tweak, you can unsolder the curent 10UF on the board and replace them with Elna RJH or OSCON.
 
#71
Your power problem comes from a bad contact on the power connector
Click to expand...

I seccond that!!!!!!

Remove the glue dot off the connector en wiglle it.
That wil solve ít.

I had the DEQ for 3 days and it started switching on-off.
When removing the power supply, in search for bad kontakts, the problem was fixed.
I never have had a power failure again.

But I also agree on the bad PCB layout.
I only took a closer look on the analog part and i think that can be done much better.

Regards Simon
 
#72
rossl said:
From post #17 in this thread:

Does anyone know what the 9V is used for? Is it the relays?
Click to expand...

Don't know.

The right Power connector pinout:

1 Red = +15V
2 = -15V
3 = 9V
4 = analog ground
5 = digital ground
6 = 5V
7 = 3V

Same on the DCX power supply (but not all used). Mod the power supply on the DCX is really a good thing. The PSU is really too small on the DCX.
 
#73
stef1777 said:


Don't know.

The right Power connector pinout:

1 Red = +15V
2 = -15V
3 = 9V
4 = analog ground
5 = digital ground
6 = 5V
7 = 3V

Same on the DCX power supply (but not all used). Mod the power supply on the DCX is really a good thing. The PSU is really too small on the DCX.
Click to expand...



Thanks. I will work on the connectors.
I think the 9V may be for the display light.
 
#76
Remote Volume Control

Hi,

has anyone ever thought of putting a remote volume control into the DEQ?
As any needed voltage is available, this with a new output stage would be a interesting feature, eliminating the pre-amp. Would the power supply deliver enough current to drive the additional units?

Thanks
Stephan
 
#77
Re: Remote Volume Control

ryssen said:
Is there a schema for the powersupply for DEQ2496?
Click to expand...

No available.

reins said:
Hi,

has anyone ever thought of putting a remote volume control into the DEQ?
As any needed voltage is available, this with a new output stage would be a interesting feature, eliminating the pre-amp. Would the power supply deliver enough current to drive the additional units?

Thanks
Stephan
Click to expand...

I don't think that the stock PSU can handle more circuit.
 
#78
I'm thinking of turning my UC into a preamp.
it should be simple.
There are 3 different inputs and i want to expand them with some relais.
Ofcource there has to be a motorpot at the analog outputs.
The thing is that with midi you can completely controll all functions so with a couple of buttons and a controller it would be easy to load a memory preset and switsh some relais.

Right now I use all 3 inputs with 2 different corrections.
2 (cd comes in optically and the pc by spdif on the xlr) have the same room correction.
For surround i use the analog inputs to adjust the center and subwoofer channels of my processor.
I was very dissapointed by the sound of both the center and the subwoofer but after roomcorrection they fit much better with my other speakers. (even though they are not corrected anymore)

I'm so pleased with it that i'm thinking to sell my processor (rotel rsp 1066) and buy me a extra deq2496 and a dvd player with multi outputs and make a multichannel preamp myself with the DEQs.

The thing is that the deq2496 has more potentials to be a good pre amp than all the **** you can buy below 2000$.
When it comes to signal handeling that is. I don't need the video switching!
The motorpot i can rip out of an old sony surround processor ESD type (its six channels). The relais will be the Nais TQ2 they are very good and can even handle the digital signals! maybe even video!
It should be easy 🙄 .

If this plan becomes more concrete i'll post it ofcource!
But the plan has just started.

Regards Simon
 
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