Till yesterday I resolved a very important first part of a problem that made me go crazy because I wasn’t be able to know why it happened and wich was the reason…
I have a Motu 896mk3, three synths and of course a pc…
I connect the Motu to the pc through a FireWire connection (with a card adapter) and the synths to the analog inputs to the Motu…
Till now when I unmuted the input of any synth through the software I heard such a “White noise”… I though it was the inputs if the Motu, but yesterday I discover it’s not! Because if I disconnect the Motu to the PC the noise is still there… Then my answer was… What’s now the problem? The outputs of the synths? The cords? The inputs of the Motu?
I switch off the PC, and that’s it!!! The noises are gone!!! The sound is now pristine!!!
It seems to be the movement of the hard drive or the ventilator, but why do the inputs of the Motu catch that noise… How could I resolve this?
One way to solve it is to disconnect the earth wire in the motu plug. In theory it is not a safe thing to do, practically sometimes is the only possible solution and there is no real risk of electrocution.
To verify quickly if this is the solution, just grab a power extension cable and disconnect the earth wire in its plug. Than connect the motu the the extension and see if the noise is gone.
Actually, in practice removing the earthing wire is not a safe thing to do and can never be recommended.
It means the only way for a fault current to flow is throw the signal wires and if none are connected or are high resistance then the other path will be through an unlucky person that touches it!!!
You should at first try plugging everything into the same extension/s from the one socket.
I’ve been investigating about this the last days and at least I’ve discovered the problem…
The transformer of my Sony Vaio is the cause of that terrible noise… If I swith on my Vaio without the transformer, only with its battery, the noise is completely gone!!! If I connect the transformer… the noise is present again…
I’ve do it with my Mackbook pro and it doesn’t matter… no noise with and without transformer…