Thanks for clarifying this in such a reasoned and understanding way! Kudos to both you and classicrockguy for your responses (and apologies made where misunderstandings occurred). Well done both of you.
Earlier classicrockguy cited a communication between you and him regarding the emissions certification required for electronic devices:
These certifications are incredibly time consuming and expensive, so to limit cost, they require the testing of a single "golden" unit. If one unit can be shown to meet the limits required, the regulating bodies certify the product for sale."Nord's position on this will essentially be that there are very strict standards which must be met by these types of electronic devices in order for countries to permit their exportation/importation around the world. All Nord models are meticulously tested to meet or exceed these requirements and these testing results are certified by independent testing labs and on file with appropriate agencies around the world. I am able to produce copies of this documentation upon request."
The statistical variation in the tolerances of the electronic components used in the assembly results in a wide variation of emissions performance for individual units. A single unit might easily fail the regulatory limits (depending on the margin by which the original golden unit passed certification). These failing cases only get noticed by officials if they interfere with radio, TV, or telephone communications.
If you have not already suggested or tried it, can Nord/American Music & Sound provide classicrockguy with a replacement power supply (or supplies) to try in his Stage?
As you say, this is a seems to be a rare problem: It seems likely that a replacement power supply ought to perform better than his present power supply.
Best regards,
-pterm
