PlanetZ forums - scopeusers.com

Hello,

When I use my lunabox 2496 I have noises (digital flows and hum) in my headphones.

Do you think I could eliminate that with a new better firewire cable ?

Thanks for help,

baba

No. It has to do with grounding issues in your setup or your screen that leaks noise into the soundcard.

that's most likely the source...
focus on outboard PSU/connections, video leaking is quite unlikely.
For a start setup a project with open analog inputs and apply enough gain you hear noise.
Remove all external connections from the Luna Box.

Then unplug the powersupply of your Display - it probably didn't change anything.
If it did (unlikely), reverse it's plug in the main outlet (or it's wallwart).
Improved or not ?

If nothing changed, you can (mostly) ignore the screen display while searching on.

Basically you apply a similiar procedure to the Luna's PSU.
(for simplicity all gear should be fed by the same outlet... otherwise the number of variables may increase significantly)
If reversing the plug doesn't change anything, check grounding of the Luna and the PC case.
Btw is the box supplied via Firewire or via wallwart ?

if nothing is connected to the box and supply comes from the PC, there shouldn't be any significant level of noise
(a little bit is always present of course)
it's most likely that the noise increases when you connect outboard gear to the Luna box.
In that case treat supply accordingly and check how each device is grounded.

To give you an impression how far such stuff may reach: I once had a fairly 'clean' setup... until I connected a coax S/PDIF cable from another PC to the amp driving the monitors. That loop folded back into Scope's analog IOs

good luck, Tom

astroman wrote: Then unplug the powersupply of your Display - it probably didn't change anything.
If it did (unlikely), reverse it's plug in the main outlet (or it's wallwart).
Improved or not ?

Do you mean 'screen display' powersupply ?

yes - and even more... you'll have to check EVERY powersupply for each item that has a direct connection to your Scope box.
Excluded are only transformer balanced devices and optical connections.

to keep the mess as small as possible it's best to start with everything disconnected and then add part after part.

cheers, Tom

Ok , I'm trying that tomorrow , and I think I'll reconnect all the home-studio

I have entierely remade my connections/cables for my home studio.
I separated audio cables from alimentation power cables.

Now the noises are considerably less but here.
I have still noises but it's not the lunabox , I tested to deconnect the box = still noises.

In monitors I can ear the noises when I up to +10 dB on my mackie VLZ.

When I record, no noises.

I think so the noises are only on the output.

But I can't test without power from my PC ! the pb is with the internal cards in the DAW (luna+pulsar II)