Problems with audio interface

Can someone help me out with the situation I have.

I'm using M-Audio 2626 audio interface at home for editing some recorded tracks and audio measurements of the stuff I build. It is a fairly simple 8 channel firewire interface hooked on my PC. It is powered by it's own (original) PSU in a box near the wall outlet. PSU is delivering +12vdc.

Whenever I turn on/off my desk lamp, unit I'm working on or anything connected to the same outlet, audio interface looses connection to the PC.

I'm thinking it's probably a short-term voltage drop/spike that it's PSU can't handle.

Would placing the 1000uF cap between +V and ground inside the audio interface, right after the DC input connector, fix this issue? Or I should look for a solution elsewhere?

I'm unable to move the audio interface to a different wall outlet since this is the only one on that side of the room.



Luka

I should have first put the capacitor in it and then ask if it's not working.
Of course - 1000uf cap solved it!
Did a stress test - turning on and off all I could hooked on that outlet and it never failed.

shot said:

I should have first put the capacitor in it and then ask if it's not working.
Of course - 1000uf cap solved it!
Did a stress test - turning on and off all I could hooked on that outlet and it never failed.

Click to expand...

I'm Happy that you able to fix this issue, this situation with some soundcards came to my attention also and I didn't know how to solve it. thanks

Bummer... I don't think I've solved it after all...

Yesterday I did a stress test and it never crashed.
Today it crashed twice!
So the problem persists

I'm starting to think that it has something to do with the firewire itself, not my audio interface...

shot said:

Bummer... I don't think I've solved it after all...

Yesterday I did a stress test and it never crashed.
Today it crashed twice!
So the problem persists

I'm starting to think that it has something to do with the firewire itself, not my audio interface...

Click to expand...

1000µ cap in the FW wire? Be sure to put it backwards or it won't explode!

I only have one FW wire that works fine, the others sometimes work, sometimes doesn't. I've tried to buy more but non of them worked, I don't know what it takes for a FW cable to work properly... FW is more complicated than USB, but when it works as it should is so much nicer. Then you need to go to gigabit but those things are more expensive, you could save a penny in the cable though.

JS

joaquins said:

1000µ cap in the FW wire? Be sure to put it backwards or it won't explode!

Click to expand...

Oh no, it's not on FW wire!
I've inserted it on the power rail of the audio interface to smooth a bit incoming 12Vdc.
This particular audio interface is powered from it's own PSU, not from the FW.

I need to do another test.
It crossed my mind that when I had those two crashes I was running my laptop on battery. But when I did a  (successful) stress test a day before, my laptop was on it's charger. Maybe it gets a ground reference through that charger and in that case it won't crash.
I feel I should do another stress test with and without laptop's charger...

shot said:

joaquins said:

1000µ cap in the FW wire? Be sure to put it backwards or it won't explode!

Click to expand...

Oh no, it's not on FW wire!
I've inserted it on the power rail of the audio interface to smooth a bit incoming 12Vdc.
This particular audio interface is powered from it's own PSU, not from the FW.

I need to do another test.
It crossed my mind that when I had those two crashes I was running my laptop on battery. But when I did a  (successful) stress test a day before, my laptop was on it's charger. Maybe it gets a ground reference through that charger and in that case it won't crash.
I feel I should do another stress test with and without laptop's charger...

Click to expand...

I was kidding about that, I assumed the power comes from it's own source and not FW, in such case is usually better using a 4 pin FW cable so you don't have dual power but that's not always available (the 4 pin connection).

Next thing I would check is the laptop charger, but if you had the crash on batteries the charger isn't the problem. If your FW cable is flexible enough (they usually aren't) you could put a ferrite with a turn around it, if not just a thicker ferrite, in order to filter some of the noise, it's used in many wires around PCs but never seen on FW, may worth trying that, if you have 2 old laptop chargers around you could take the ones they have and try with one at each end, or at least one as starting point.

JS

do you have a good ground conection at your house? I had problems in my old apartment, it didn't have a ground conection.

12afael said:

do you have a good ground conection at your house? I had problems in my old apartment, it didn't have a ground conection.

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Actually I don't!!
Earth is connected to neutral. Though it's illegal nowadays, It's not uncommon here in my town in old buildings.
Unfortunately, I'm in a rented apartment so I can't do anything about it...

Hi,

shot said:

Actually I don't!!
Earth is connected to neutral. Though it's illegal nowadays, It's not uncommon here in my town in old buildings.
Unfortunately, I'm in a rented apartment so I can't do anything about it...

Click to expand...

Earth connected to neutral? No way it would work.

I think the motu PSU don't connects to Earth anyway. Usually, this kind of Psu is made of plastic so it doesn't need protection.

Thomas

i had many problems with this, you need a good reference clean ground between equipment, what i did was connect a wire to the water pipe on the bath room, that is my ground connection for just my audio gear. that solve my problem.

In the US, the Neutral is always connected to Mother Earth.
The Safety Ground/Protective Earth is connected to the Neutral which like I said is connected to Mother Earth.
Where and how the Neutral connection to Mother Earth is made is controlled by NEC rule.

Note that in some 3 phase industrial systems the rules are very different.

Also check the outlet wiring. I have many in my house where the ground is floating. Note: Having the ground connected can make  weak interfaces worse is audio is not well segregated from EGC currents (see pin 1 problem).

FWIW ground connections between professional audio gear should only carry shields. Audio should be passed differentially between audio + and audio - (not ground).

JR

shot said:

Earth is connected to neutral. Though it's illegal nowadays, It's not uncommon here in my town in old buildings.

Click to expand...

When you say that, do you mean, "connected to neutral at each outlet?" Because that's illegal and stupid.

Earth is required by code to be bonded to the neutral back at the service panel.

Unfortunately, I'm in a rented apartment so I can't do anything about it...

Click to expand...

You can tell your landlord that the building has a fire hazard.

-a

+1... per code ground is bonded to neutral one time only at or near the service panel.

Bootleg ground connections like wiring ground to neutral in each outlet is dangerous for multiple reasons.

JR