Ahhh... source mains lead you mean ? So you have NAD + the signal leads all coupled up and connecting the two components but the filter is not connected to the mains.
That points to a radiated field from a transformer inducing current into the unpowered circuitry of the filter. That is further reinforced by the fact that the NAD volume control has an effect on level, the hum is a appearing as a "valid" input signal signal.
To prove that theory you have to physically move the filter away from where it is now... just hold it in the air while coupled to the NAD via the signal leads only. You should find it silent when away from any radiated fields.
You are right.
The W-ASP sits on top of my CD player/DAC tidily hidden inside a TV bench (no TV, though). If I relocate it onto the top surface of the bench the hum ceases.
Thanks for taking the time to lead me through this - it's been a useful learning experience. Now I'm left with the problem of how to house the W-ASP!
Martin
The W-ASP sits on top of my CD player/DAC tidily hidden inside a TV bench (no TV, though). If I relocate it onto the top surface of the bench the hum ceases.
Thanks for taking the time to lead me through this - it's been a useful learning experience. Now I'm left with the problem of how to house the W-ASP!
Martin
You are welcome... and its good to have found the reason why even if a solution may prove tricky. You might get varying degrees of success with metal shielding (an aluminium plate but its not ideal). Try anything you have, a tea tray, anything and see if it helps. The best shielding is to use mu-metal,
Mu-metal - Wikipedia, the free encyclopedia
Very very expensive though. Distance is the best and cheapest solution.
Mu-metal - Wikipedia, the free encyclopedia
Very very expensive though. Distance is the best and cheapest solution.
pleased to hear you have found a solution.- Status
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