Modify behringer DEQ2496?

[janneman]

Originally posted by FLECOM


according to the datasheet the 96 dosent need any dc blocking on the output at all...

Where in the data sheet does it say that? Can you show that part? I didn't find it. AFAICS, the outputs sit on 2.5VDC. You can't make that disappear.... Unless you do a balanced to SE conversion as noted before.

Jan Didden

[janneman]

The AX article:

http://www.audioxpress.com/magsdirx/...didden2657.pdf

Jan Didden

[densen2002]

densen2002, the file has gone. May I ask for a repost (or email)?

http://kinap2002.narod.ru/eos.rar 10M (unlimited hosting)

[zanash]

stupid question, how do I open eso.rar ?

[ds23man]

Originally posted by densen2002


http://kinap2002.narod.ru/eos.rar 10M (unlimited hosting)

It does not work!

GRG

[Ken L]

Originally posted by zanash
stupid question, how do I open eso.rar ?

use winrar -


google to find

[Ryssen]

The right Power connector pinout:
1 Red = +15V
2 = -15V
3 = 9V
4 = analog ground
5 = digital ground
6 = 5V
7 = 3V

I believe the 9V goes to the regulator LM317 that powers the dac and other chips, so this supply is very important. But somebody please double check.

Is this true?I am planing on making a better supply for the DAC,is it the 9v I shoul supply NOT the 5V?How much is the current draw?
Anyone done this?

[Ryssen]

I believe the 9V goes to the regulator LM317 that powers the dac and other chips, so this supply is very important. But somebody please double check.

Sommeone figured this out yet??I really would like to know wich of the regulators goes to the DAC??

[CLS]

Yes, I know this is an old thread...

Anyway, inspired by this & this , I recall the wonderful DIY DAC I used several years ago, which came with transformer line stage.

That DAC was an evaluation board of CS4397 & I skipped the whole analog stage on the board with a pair of Lundahl 7902. That was inspired by this.

Tranformer-coupled DAC is awsome, period.

By comparison, the OP analog stages sound mechanical & grainy. On the other hand, transformer-couple sound lifelike & fluid. In good recordings, the sparkle & airy decay of the cymbals are simply amazing. In those records without noticeable trebles, the "atmosphere" are also remarkable....

Sadly the evaluation board died after only about 1year of use, and I could not fix it. (tried but failed)

Later I bought DEQ2496. Using it with digital input & analog output, it serves both EQ & DAC functions. In the EQ portion, it's doing great. In the DAC portion, it's not.

Looking into the boards inside the DEQ2496, those tiny SMD scared me away everytime. (you guys who can deal with them just amaze me! ) So, despite the imperfection of the analog stages, eventually I get used to its sound.

Until now.

I think, I made a tranformer-coupled analog stage before, why not now?

I traced the analog output pins of AK4393, I found they connet to R13, 14, 16, 17 (2k in value) on the back of output board. R13/R14 are L-/L+; R16/R17 are R+/R-.

I just attach thin wires on them & connet to pin2/3 of the output connectors. (Of course those connector are disconnected from the board) I need the AUX output for other usage so I leave everything else untouched. Now the DA chip is driving both downstream coupling transformer & the analog stage of AUX output. Maybe or maybe not, I'm not sure. With extra load of 10k, I'm not worried.

Anyway, all those tiny SMD and copper foil traces are so complex to me and I'm not willing to destroy any of them. So I'd better leave it that way...

Now the output of the XLR connetors is differential with 2.5V DC offset. Luckily those wonderful Lundahl 7902 are now sitting at the input of my preamp with floating primary winding. So the DC offset dose not matter.

The fluid, airy, open sound came back immediately. Oh, how I miss that. So, with only 4 short & thin wire, the sound of this box transforms a great deal.

The drawback is, the output level drops a lot. I must turn up a lot more on the knob. And the punch, dynamic, energy of the bass seem weaken a bit. This dosen't bother me very much, since the textures & overtones are now much much better which overshine.

[ampsarus]

Originally posted by seoman


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

I am having the same trouble with my DEQ after 1 day of use. Was it the DC or the AC connection(s) that was the culprit? Thanks!