shot

Audio interface for testing is giving me headaches
« on: September 06, 2016, 08:23:35 AM »
Hi,

I've been having this problem for a long time but it was occurring not frequent enough to push me into investigating solution.

I have M-Audio Profire 2626 audio interface on my workbench that I use for testing stuff I build. It's a 8in/8out firewire interface. Simple, nothing fancy...
This audio interface uses external small AC-DC power supply. This PSU is on the same wall plug (europe, 220vac) as all my other equipment. It's a bedroom in my apartment and I have only one wall plug in this room. Basically everything is on this plug. Can't change that.
Audio interface is connected to my computer with firewire.

Now the problem.
Every time I turn on the desk lamp, every time I turn on the unit I work on or whatever I turn on, I loose connection between my pc and audio interface! Cubase reports that it has lost driver and audio interface starts blinking LED stating that it has no connection. I guess that's some voltage drop or bump that causes this interface to loose power for a fraction of a section and it causes some sort of break in firewire connection.
What could be done?
It crossed my mind to add some large capacitors inside the audio interface right after the dc connector to smooth the voltage a bit, but I don't think there's space to fit those caps.
I don't have money to buy expensive power conditioners (furman and similar), and from what I've read those small office UPS units don't provide ac line filtering enough smooth for this kind of problem. After all, this is happening only with this audio interface. I've had other interface on my bench and it didn't behave like that.

Can anyone think of a simple fix for this?

:)

Luka

p.s. sorry if I posted in a wrong section! Feel free to move this post elsewhere!


Pip

Re: Audio interface for testing is giving me headaches
« Reply #1 on: September 06, 2016, 11:16:18 AM »
UPS!!! Uninterruptable Power Supply!

APC is my flavor of choice.
Pip
New York City
http://geosonixlab.com

john12ax7

Re: Audio interface for testing is giving me headaches
« Reply #2 on: September 06, 2016, 11:01:37 PM »
Zdravo shot

I had a similar problem. USB dac in living room would lose sync if an appliance like a blender turned on in the kitchen.

Did you contact tech support? On some level you have a common problem, though you are not dealing with large appliances, so it seems your interface is overly sensitive. Could be something actually wrong with the power supply.

For solutions the simplest is often to run things on different electrical outlets. If not possible next is to look at the power supply. You can add ac snubbers to limit the voltage spike. As well as additional dc filtering. Something like a pi filter, caps to ground, series inductor. I think Dan at collective cases makes a PCB for this. You might need to make a separate box for this.

If you could measure the spike in the dc line it would give a better idea of what you are dealing with.

Michael Tibes

Re: Audio interface for testing is giving me headaches
« Reply #3 on: September 07, 2016, 03:58:58 AM »
Kill the source or make the receiver less sensitive: what exactly causes the spikes? for example can you replace the lamps with different types which cause less spiking? you could also try additional power line filtering. UPS might be a solution as well sa mentioned, but maybe not really cheap.

Michael

joaquins

Re: Audio interface for testing is giving me headaches
« Reply #4 on: September 07, 2016, 04:48:05 PM »
  Did you tried with a ferrite bread on the signal wire? sometimes helps... I have a problem with my FW loosing connection and needing reset but I couldn't replicate the problem to then try to solve it. I also do have a loosing of signal for the video on my desktop (HDMI and DVI with 2 different displays) when I turn off the fan in the room, but it recovers right away so isn't nearly as problematic, I've thought in adding a cap in parallel with the winding to correct the power factor but I'd need to know to start with...

  In your case I'd try with the LC filter for the mains. It could be a problem of the interface or the computer.

JS
If I don't know how it works, I prefer don't turn it on.

shot

Re: Audio interface for testing is giving me headaches
« Reply #5 on: September 07, 2016, 05:39:57 PM »
I'd have to try with LC filter. That seems reasonable. Could work!

Today I got from a friend UPS unit and I'll try to hook it up. Right now I don't have male IEC connector at home so I couldn't try it immediately. If it would help, I'll try to buy myself used one.
But still, I'd also like to fix it inside the audio interface so that I can carry this interface around when I have some recording gigs. It's decent enough to put some TLC into it.
I'm sure it's not computer that is problematic. I've tried it with my home desktop pc and with two different laptops. It's always the same. But it didn't occur when I tried another interface that I borrowed from a friend.
:)

L

arnyk

Re: Audio interface for testing is giving me headaches
« Reply #6 on: September 14, 2016, 11:55:41 AM »

I have M-Audio Profire 2626 audio interface on my workbench that I use for testing stuff I build. It's a 8in/8out firewire interface. Simple, nothing fancy...
This audio interface uses external small AC-DC power supply. This PSU is on the same wall plug (europe, 220vac) as all my other equipment. It's a bedroom in my apartment and I have only one wall plug in this room. Basically everything is on this plug. Can't change that.

Audio interface is connected to my computer with firewire.


Every time I turn on the desk lamp, every time I turn on the unit I work on or whatever I turn on, I loose connection between my pc and audio interface! Cubase reports that it has lost driver and audio interface starts blinking LED stating that it has no connection. I guess that's some voltage drop or bump that causes this interface to loose power for a fraction of a section and it causes some sort of break in firewire connection.

the desk lamp power switch operation creates a burst of RF that is picked up by the FW connection and temporarily causes it to lose synch.

Quote
What could be done?

(1) Different desk lamp that does not have such an electrically noisy switch.

(2) Reroute wiring to reduce coupling of noise into the FW cable.

(3) FW cable with better shielding.


Quote
It crossed my mind to add some large capacitors inside the audio interface right after the dc connector to smooth the voltage a bit, but I don't think there's space to fit those caps.

To test that hypothesis, pull the power plug on the power supply and see how long it takes for the error to manifest itself.  If it is longer than 1/2 second, your diagnosis is not supported.

In general most modern gear will run for a second or three before they  drain the PS caps.

abbey road d enfer

Re: Audio interface for testing is giving me headaches
« Reply #7 on: September 15, 2016, 01:45:54 PM »

Every time I turn on the desk lamp, every time I turn on the unit I work on or whatever I turn on, I loose connection between my pc and audio interface! Cubase reports that it has lost driver and audio interface starts blinking LED stating that it has no connection. I guess that's some voltage drop or bump that causes this interface to loose power for a fraction of a section and it causes some sort of break in firewire connection.
I doubt it. It would take a lot of effort to make a so badly designed PSU :o
I rather think the issue is an EMI problem. Switching spikes are picked up by the FW connection or any other sensitive area of the interface. I would think it is conducted emissions, not transmitted (you may check by putting the interface in an earthed metal enclosure), so I would suggest the use of an in-line EMI/RFI filter on the interface power inlet or, as suggested earlier, a ferrite toroid on the low-voltage cable.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
"The important thing is not to convince, but to give pause for thought." (B. Werber)
Star ground is for electricians.

shot

Re: Audio interface for testing is giving me headaches
« Reply #8 on: September 15, 2016, 04:26:40 PM »
Guys,

I was on hold for a few days with this issue until I borrowed from a friend UPS device.
When I installed it and plugged my PC and audio interface, all problems were gone.
Seems that it has built in some sort of EMI/RF protection so it keeps things stable.

I'll try to buy used UPS and be done with it.
It's to complicated to install power line filtering into the device. I've opened it and there's not much space.
If I grab an UPS for cheap it will be quicker and less painful fix

:)

Luka

Whoops

Re: Audio interface for testing is giving me headaches
« Reply #9 on: October 08, 2017, 06:57:09 PM »
Guys,

I was on hold for a few days with this issue until I borrowed from a friend UPS device.
When I installed it and plugged my PC and audio interface, all problems were gone.
Seems that it has built in some sort of EMI/RF protection so it keeps things stable.

I'll try to buy used UPS and be done with it.
It's to complicated to install power line filtering into the device. I've opened it and there's not much space.
If I grab an UPS for cheap it will be quicker and less painful fix

:)

Luka

You can buy used APC UPS's for cheap.
Some of them will be fine, some you will have to change the battery for a new one.
Batteries are commonly available and prices range from 25 to 50 Euros

You could also check the original PSU specs and maybe build a DIY PSU for it based on pcb's and projects from this forum


trobbins

Re: Audio interface for testing is giving me headaches
« Reply #10 on: October 10, 2017, 03:46:13 AM »
If you just have one AC mains socket, then it sounds like you must use a 'power board' with multiple outlets to connect all your equipment.  If you have  (or can temporarily borrow) an additional 'power board' then you could try plugging it in to your existing power board, and use it just to power your audio equipment.  That may attenuate any disturbance caused by other equipment - if so then a bit cheaper, and less hassle than a UPS.

Another option is to use an isolation transformer to power just your audio gear (eg. something like 150VA size, with the protective earth passing through from input to output).  That may also be cheaper and easier.

Re: Audio interface for testing is giving me headaches
« Reply #11 on: November 21, 2017, 08:20:34 PM »
What sort of bulb do you use in the lamp ?
Energy saver CFL bulbs tend to cause a disturbance on the mains line when switched on ,they also tend to spew rf hash into other sensitive circuits nearby.
Maybe try a halogen bulb instead ,not quite as efficient ,but a more pleasing light from them ,and no noise or switch on spikes.