Nord User Forum

SOULidarity wrote:I would likely stay with the 125mA. Fuses are current devices, wattage is irrelevant.

Wattage is not irrelevant. Wattage is voltage x amps (current). If the voltage is double, the current is halved. If the voltage is halved, the current is doubled.

The fuse should be on the primary side of the power supply, so moving from 220v Euro to 110v USA would increase the current draw by 2x and the fuse should be doubled in amperage.

Maybe the quiescent state current which should be well below the rated fuse value. You are simply trying to prevent more than 125mA from entering the power supply

Won't you have to send it back to Germany if it needs warranty service?

SOULidarity wrote:I would likely stay with the 125mA. Fuses are current devices, wattage is irrelevant.

Amps=Watts/Volts

It's not as simple as Ohm's law. The power supply is not linear, it's a switcher. The voltage selector switch does not simply double the input coil resistance of a transformer. Haven't anyone here had to use a voltage selector switch on a PC or some type of electronics? Did you change the fuse? Doubtful. At any rate, it's probably not an issue.

SOULidarity wrote:It's not as simple as Ohm's law.

This isn't about Ohms Law, it's a power calculation. The Nord uses a fixed amount of power (Watts). When the Mains voltage doubles, the Mains current halves to keep power constant. Since the fuse is on the Mains input, you must change the fuse as described to correctly protect the Nord.

SOULidarity wrote:The power supply is not linear, it's a switcher.

Traditionally, Nords used linear power supplies. That may have changed on the Stage 3, but it doesn't change the amount of power the device consumes.

SOULidarity wrote: The voltage selector switch does not simply double the input coil resistance of a transformer.

Based on previously available Nord Electro 2 schematics, the voltage selector switch changed the turns ratio of the transformer based on the input voltage to provide the correct voltage at the transformer output. Since the number of turns is directly proportional to the resistance, the switch changes the transformer's resistance by a factor of two. This might no longer be the case for the Stage 3, but it remains a possibility. Again, this does not meaningfully change the power consumed by the Nord.

SOULidarity wrote: Haven't anyone here had to use a voltage selector switch on a PC or some type of electronics? Did you change the fuse? Doubtful..

This isn't relevant. The Nord's provide a user-accessible Mains input fuse and it needs to be changed as described to match the Mains input voltage to properly protect the Nord. The type of over-current protection in PC's or other electronics matters not at all.

SOULidarity wrote: At any rate, it's probably not an issue.

Correctly and safely protecting the Nord and it's users is an issue that I encourage you to make an effort to understand for your own safety.

I didn’t realize we were going to go down this path regarding the fuse, but I assure you that I did my homework. I’m pretty sure if anyone checks a US (115V) Stage 3, it will come with a 250mA fuse pre-installed from the factory. As pointed out above, the NS3 uses/requires the same amount of power regardless of the voltage. If you put a 125mA fuse in a 115V set Nord, it will blow. Maybe not immediately, but it will blow prematurely because in order to power itself, it will need to draw more than 125mA of current at 115V.