Modify behringer DEQ2496?

[stef1777]

Originally posted by Ryssen

Would this work with a LT1763 2,5v?Different pinout ofcourse.

I don't know. The DEQ v2 was not mine. Just one to upgrade and it left.

In fact, I don't realy know what is this component. I took a picture.

It can be read: F D65AB and 11120 05/06.



Seems to be from Fairchild.

Concerning the 3.3v, I also discovered that inside the DEQ v1, Behringer mixed analog and digital 3.3v. They produce analog 3.3v with the same 3.3v and just insert a coil just before the chip pin... As in the DCX in fact.

Have a nice digital low noise psu is important in fact.

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[Ryssen]

Ok,but in DEQv1 (the one I have)maybe the LM317 could be substituted with a LT1763 2,5v on one of your miniregPCB`s?

[stef1777]

Originally posted by Ryssen
Ok,but in DEQv1 (the one I have)maybe the LM317 could be substituted with a LT1763 2,5v on one of your miniregPCB`s?

We need to look what is powered first with 2.5v. In theory, you can remove the 2 resistors and fit a fixed reg in place. But good luke with the legs.

Let me finish do draw the dsp board psu. I'll post it tomorow.

Stef...

[stef1777]

DEQ2496 v1 DSP PSU schematics
http://www.awdiy.com/index.php?page=references

Look what they have done with ground and to produce the analog 3.3v...

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[janneman]

Originally posted by stef1777
DEQ2496 v1 DSP PSU schematics
http://www.awdiy.com/index.php?page=references

Look what they have done with ground and to produce the analog 3.3v...

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Stephane,

Good job! Isn't this the same supply that is used in the DCX2496?

Jan Didden

[stef1777]

Originally posted by janneman



Stephane,

Good job! Isn't this the same supply that is used in the DCX2496?

Jan Didden

No exactly the same. If I understand the DCX schematics, they produce the +3.3vA with the +5vD using a transistor. On the DEQv1, they directly use the 3.3vD with a coil to ovoid high frequency go back.

The big difference between the DCXv1 and the DEQv1 is ground plane. Only one mixed for the DEQ (AGND and DGND pins from AKM chips directly connected to the same ground). One analog and one digital for the DCX. DEQv2 DSP seems completely redesigned on this.

This may be explain why with the best possible psu, we still have a low level ground noise.

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[zanash]

stef1777

nice web site !

[AR2]

Originally posted by stef1777


No exactly the same. If I understand the DCX schematics, they produce the +3.3vA with the +5vD using a transistor. On the DEQv1, they directly use the 3.3vD with a coil to ovoid high frequency go back.

The big difference between the DCXv1 and the DEQv1 is ground plane. Only one mixed for the DEQ (AGND and DGND pins from AKM chips directly connected to the same ground). One analog and one digital for the DCX. DEQv2 DSP seems completely redesigned on this.

This may be explain why with the best possible psu, we still have a low level ground noise.

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Stef, with that knowledge wouldn't be the best to redesign your board and include all those voltages, including 9V regulated, or make separate board that will solve these issues. After that we just have to look where to cut the traces and completely abandon Behringer PS mess. It seems like that there is no other option. That way we could have one universal power supply for DCX and DEQ, that could incorporate your nice regulators. I have schematics for DCX that shows DSP power supply regulators (not switching supply) and will be happy to send them to you if you need.

[zanash]

did you consider discrete psu for each voltage a la audio synthesis ?

[badduh]

Originally posted by sendler
I like the direct out mod.
http://mysite.verizon.net/vze4c5pt/id14.html
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That looks very interesting, i was looking for information to upgrade the opamps and caps, but i like to try this mod first. unfortunately I'm a newbie to dacs so i can use a little help
I can't see on the photo how the caps are wired up, could someone please explain that to me?

Photo