Nord User Forum

I´ve seen a lot of posts about the transformers inside our Nords to be buzzing and noisy.
It´s not my case, my Electro5d makes absolutely no audible noise. But I have a problem when stacking it over my Rhodes...
There´s an incredible high induced noise in the Rhodes´ signal... it´s Impossible to use...
I have to lift the nord more then 25-30cm to get rid of the humm. Tried to connect the Nord to different wallets..
Rhodes is super silent with the Retroflyer preamp installed and it´s great isolated.
I know aluminium is not effective, so there is any other solution around?
How could I shield the rhodes for the magnetic field of the nord does not interfiere?¿?¿?¿?


Thanks!!

Never tried this myself but I heard of people lining the inside of the Rhodes cover with metallic (sticky) tape and then connecting a cable from the metal lining to the ground of the audio signal. I also heard that placing a metal sheet between the rhodes and the top instrument helps (similar principle, trying to create a 'Faraday's cage').

Mr_-G- wrote:Never tried this myself but I heard of people lining the inside of the Rhodes cover with metallic (sticky) tape and then connecting a cable from the metal lining to the ground of the audio signal. I also heard that placing a metal sheet between the rhodes and the top instrument helps (similar principle, trying to create a 'Faraday's cage').

Yes but that depends on the metal you use for that... I tried aluminium, but it´s not working... Just trying to find someone that have found something that actually works...
Thanks for your response

I think you might even ask the Nord support - or your national distributor. Maybe they have an idea about that - that would be another type of support I'd appreciate: 'Any comments about using your product in my special environment???'

pabloevaristo wrote:

Mr_-G- wrote:Never tried this myself but I heard of people lining the inside of the Rhodes cover with metallic (sticky) tape and then connecting a cable from the metal lining to the ground of the audio signal. I also heard that placing a metal sheet between the rhodes and the top instrument helps (similar principle, trying to create a 'Faraday's cage').

Yes but that depends on the metal you use for that... I tried aluminium, but it´s not working... Just trying to find someone that have found something that actually works...
Thanks for your response

Aluminium should work fine. I used household aluminium foil to shield my Clavinet D6, and those things are notoriously hum-sensitive (like, "neighbour's electric toothbrush causes buzz" sensitive).
The foil needs to be grounded, though.

If shielding/grounding the top of the Rhodes doesn't completely eliminate the hum, a noise gate can work well at dropping the hum when not playing on the Rhodes. Good luck!

Maybe you need a thicker sheet? Thickness (as well as material) seem to make a difference. See graph in https://en.wikipedia.org/wiki/Faraday_cage

Way back when I owned a Rhodes (1976 Mark I Stage), I built my own custom flat top for it. I lined the inside of the top with a thin copper sheet and connected it to the chassis ground. It seemed to take care of the problem.

I'm an electrical engineer and have designed electromagnetic shielding systems for electronic circuits. I assume the hum is 60 cycle noise caused by a transformer - likely the power supply transformer - generating a magnetic field. If that is the case, electric field shielding using a a non-magnetic conductor such as aluminum or copper will not be effective, because those materials are typically used for RF electric field shielding. Instead, a material with high magnetic permeability is required, such as 3M 1380 sheet. A solution in that case could be adding magnetic shielding using 1380 around the problem transformer, which might be the power supply transformer.

There is a possibility that the issue IS caused by an electric field rather than a magnetic field, so you might try again with aluminum foil between the two instruments, this time being sure to ground the foil with a length of wire to a good ground on the piano. I would start with the metal body of the piano's output jack, because that is easy. If that works let me know and I'll suggest a way to install a permanent electric field shield inside the cover.

Personally I would just set the two keyboards up in an L-configuration....