Modify behringer DEQ2496?

Rapid,

What do you think of the DEQ2496? I've been looking at the Ultramatch Pro 2496, was wondering about the quality of the D/A conversion. Probably the same DAC as the DEQ2496. I'm thinking of getting one & then modding it heavily - it's cheap enough, if I screw up, I can throw it away & buy another. I was thinking of maybe using transformer outputs instead of op-amps...

...but the basic DAC has to be good enough to work with.

Sorry, I know this doesn't answer the question you asked - but maybe we can start a trend?

Bat
 
Hello Bat!
Sure, I'll copy my reply from another message board (audioasylum) because the question was almost the same :) Hope you don't mind:

All signal is passed through the 2496 but I only choose to equalize the bass range because I haven't succeeded in eliminating the peaks in the midrange perfect. That's why I'd use acoustical damping instead.
It's a pretty big difference if I put some pillows on the floor infront of the speakers. It smoothens out the response above approx. 1Khz

This is how things are connected:
CD/transport -> Digital optical inputs on the behringer (it's either optical or AES/EBU (?) )
Analog phono (XLR availible) outputs -> (phono->RCA converter) -> active filter


I'm using analog out with the built-in DAC. To me it sounds good but since I've heard people complain about the Sss sounds (and some don't), I'm not sure if my demands are lower than "audiophiles". Some people claim they can hear difference in cables. I can't but I hear a small difference when my friend connects his $160 PS Audio DAC to his pioneer CD player.
If I could choose wether to buy it again or not, I'd buy it. Maybe you can borrow it from a shop and try.

There's digital output from the DEQ2496 so you can run your favorite DAC instead of the built-in.

Cheers,
Mattias
 
Thanks for that, Rapid.

I'm pretty much decided now to get the Ultramatch Pro. As far as I can see, there are no unblanaced outputs, so I'm planning to add a couple of Lundahl line transformers, maybe bypassing the output op-amps, depending what I find when I open it up.

Might get the DEQ2496 as well tho...
 
Inside the deq2496

Just to revive this thread.:smash:

I just got this gear, the boards inside are very compact, not much room to mod.
 

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Re: Inside the deq2496

Konnichiwa,

ChuckT said:
I just got this gear, the boards inside are very compact, not much room to mod.

Well, the Op-Amp's for the analogue stages are on the board with the connectors on the back. You can upgrade these and also of course you could use a lot of the present space to fit input and output transformers completely replacing the active analog stages....

The PSU should also be easily improved....

Sayonara
 
Here is the output stage. Cheapo opamp at work here, will replace them with either AD8066 , AD8620 or LM6172 .
May be replace the whole output stage when I find the time and the right circuit, or may just a single transformer.
 

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Konnichiwa,

ChuckT said:
what would be a good output trans?

Depends upon the circuit you are going to use. There are quite a few good 1:1 types, but they are not really suited to directly interface with the DAC.

ChuckT said:
I have got a UTC W-786 600 to 600 trans on hand, thinking about using as a balance cable to single conversion .

Should be fine for that.

Sayonara
 
Konnichiwa,

ChuckT said:

Here is the output stage. Cheapo opamp at work here, will replace them with either AD8066 , AD8620 or LM6172 .

Any of the above will do fine. I'd say AD8620 on the analogue inpoit side, AD8066 or LM6172 on the output side.

stef1777 said:
Do not work. You need +/- 15V op-amp.

Actually, the supply in the Behringer was +/-12V, last time I looked (inside my own), so au contraire, does work just fine....

Sayonara
 
Actually, the supply in the Behringer was +/-12V, last time I looked (inside my own), so au contraire, does work just fine....

Sayonara [/B]


I'm very surprised.

Mine is +/- 15V. It use JRC LM7815A et LM7915A in the switched power supply (It has 17,7V before the regulators). It has +15V on the red wire, -15V on the second wire of the power connector.

I used OPA2604AU.
 
Thanks KYW.:)

Strange, it seems there are different configure out there for this gear. Mine uses LM317 & 7805. I found only those 2 regulators on board, maybe there are smaller ones that I've missed.
Here's the pic.
 

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Ceramic cap coupling?

Your are right, I see the 7915/7815.
And thanks for the power connector info, very useful.

One thing is bugging me after a bit of probing on the output circuit. Why are there ceramic caps directly couple to the balance out, it is directly in the signal path!!!:xeye:
Surely this can't be good!!