Will someone evaluate my headphone system?

[rtteter]

(sorry for the multiple posts this week, I'm a noob)

Ok - So I have the AN/DM card. I am trying to route my DAW outputs to the AN/DM card outputs (8 mono outputs). THEN, those 8 outputs are going into 8 return channels on my snake to/from the tracking room. THEN, I come out of the returns in the snake box and into four separate 2 channel behringer analog mixers. hence - 4 headphone stations, each with two faders - the entire track and the Muscian's instrument ("more me"). The track is routed via an aux/buss send created in logic.

It works- for about 10 mins. And then the audio in the personal behringer mixers starts to crackle and pop and distort and fade and it gets worse and worse and worse. Do I maybe just have a clock issue?

 

[cmaffia]

I route in a similar fashion for my headphone mixes. Does the crackling happen on all 8 channels? Does it simultaneously happen on all behringer mixers? Can you simply the route to rule out bad snakes/wiring or behringer mixers? This can range from bad cabling to failing DAC on the analog card.

 

[rtteter]

All 8 channels!

Also I'm running an aggregate system. Running a focusrite 18:20 in tandem with the 4800. Could that be it?

 

[cmaffia]

Don't know. Take it out of the equation and test the outputs of your analog card without snakes. Just go to your headphone amp directly and see what happens.

 

[rtteter]

Could it be that there is no headphone amp?

Out of card. Into snake return. Snake return goes into mini mixer. Headphones out of mini mixer. I figured the mixers were acting as amp?

 

[cmaffia]

Mini Mixer should be fine. Go straight to the behrigner then and take out the focusrite to rule out clocking issue. Keep it simple to rule out DAC on analog card or cabling. Don't use snake use patch cable for testing. Are you sure it isn't your mini mixer? Can you test it with other signals not from the DM?

 

[ampsarus]

If all of the head stations work fine then slowly distort into inaubility one and all, what could it be but sw?. Take a close look at the daw and computer. Sounds like a time out in OS.

Try another config to rule out the IF card, but it's probably a ok.

 

[Arjan P]

Can't quote for some reason but @ampsarus: Slowly fading into distortion and crackling can certainly be from analog components failing, capacitors for instance. So it could still be the AN-DM card.

 

[cmaffia]

The symptom suggests a failing component somewhere in your chain. You said the crackling happens simultaneously in all 4 headphone stations. If that's a true statement then there's a single point of failure somewhere. I doubt it's the snake or all 4 headphone mixers but you need to rule them out. Most likely there's an issue with either the analog card or the DM slot/board the analog card is plugged into.

I'd troubleshoot this from the "inside-out" meaning test each connection path starting with the shortest path first and then add the next connection until the problem occurs.

1. I still don't understand how your Focusrite hardware is integrated in your setup but for expediency, I'd just take it out of the equation for testing purpose. If removing it from your work flow doesn't resolve the issue then proceed.

2. Long shot, but check the source in Logic. Monitor the AUX/BUSS send from your DAW and make sure the signal doesn't behave this way. I believe you can do that in Logic's mixer. Cubase's Control Room allows me to monitor all cue sends before the signal is sent externally.

3. With another patch cable, test each of your analog card's outputs (don't test using the snake or your headphone stations yet as those are your next series of tests). You can use another headphone amp or even use the DM's line inputs to test. If you hear crackling at this point then there's no reason to test further as the problem is your analog card.

4. If the output of the analog card doesn't crackle in the previous test then test a home-run connection to each of your 4 headphone stations.

5. If all is good to each of your headphone stations, then introduce the same tests with your snake.

Some other questions: Did you recently buy your DM4800 with all it's expansion cards and you're trying to set it up for the first time? Did your headphone monitor setup work before and this is a new issue? Lots of people are buying used DM3200/4800's on eBay these days and I'm just wondering if you "inherited" an issue.