Behringer DEQ/DCX mods at pro line levels?

Jump to Latest
T

tommus

Member
Joined 2009
I'm using a DEQ2496>DCX2496 in my PA rig. Sounds pretty OK to my ears, especially for the $$$.

For pro levels is there any significant benefit to doing any of the analog input/output mods that seem to be so popular? If so, where is the bang for the buck?

Thanks!
 
Pano

Pano

Administrator
Joined 2004
Paid Member
I currently have a DCX in a pro rig and am using transformer only outputs on lines 3-6. Outputs 1&2 (woofers) are the stock circuits. There has been some PSU modification.
Works well for me. Just need to roll down the gain on the bass amps more than the horn amps.
 
T

tommus

Member
Joined 2009
Pano, I see that you've been doing these mods for quite a while...

When you say "transformer only" outputs, what are you bypassing?
Or just putting a transformer on the line out? Do you recommend a particular model of transformer?

Regarding the PSU, what did you do?

Thanks!
 
Pano

Pano

Administrator
Joined 2004
Paid Member
Sorry I missed your post - been a little busy.

With the transformer out all active parts after the DAC chip are bypassed. The transformer is connected directly to the DAC output. IIRC, the AKM chips are specified for a 1K ohm load, but I don't load them that heavily. I usually put 3K-5K across the secondary of the transformer and let the next device in line provide the rest of the load.

I have used Edcor, Jensen, Cinemag and Onetics line level transformers. All of them good. There have been other brands I didn't like. The Jensen and Cinemag are easy to get and sound great. Typically I use a 1:1 ratio, but have also done 1:1.4 and 1:2 step up. You can use smaller transformers on the mids and highs, save the big ones for the bass.
 
T

tommus

Member
Joined 2009
I am connecting the DEQ to the DCX like bob4 has suggested. So I need input for the DEQ and output for the DCX. That Kappa board looks nice, but I'd need two build two of them, one for each unit, although I guess I could just leave the input components off one and the output off the other. On further reflection, I'm not even sure I can use the Kappa board with the DEQ. (BesPav, do you know how much all the components for the Kappa board would cost anyway?)

I think I might try the transformer output for the DCX. It's simple (but not inexpensive!)

So that leaves me hanging for the input to the DEQ. There is an input board mod from behringermods.com but it says it can only accepts a 2V input. I don't know what would happen if it were overdriven, as happens often when someone else is in control of the master on the mixer! The Behringer stock input can accept much higher levels.

Maybe I should just be looking for an ADC to put in front of the DEQ. This looks like it would do everything I need. Also not inexpensive but I am realizing there no free lunch.

Any thoughts?
 
Pano

Pano

Administrator
Joined 2004
Paid Member
You are correct that there is no free lunch. :up:

I've made analog input boars for the DCX but always used the DEQ in digital mode. The input boards weren't complex, just some opamps in basic layout. The ADC inside the Behringer needs a low impedance to drive it. Also need to be differential. If you are coming in hot from a mixing console, you'll need some attenuation.
 
T

tommus

Member
Joined 2009
So I bit the bullet and ordered some Cinemag output transformers. (unfortunately I'll need to wait a month while they build them)
I opened up the DCX enclosure and realized that I'll need to pull out the entire analog I/O board...

Question: Do I need to do anything to the incoming AES signal from the DEQ? Or just pass it to the DSP board? It is accepted on the analog input "A" so I'm guessing it would normally be going through the input stage circuitry.
 
You must log in or register to reply here.
Top Bottom