grounding issues

[Abraham]

My rhodes has a grounding noise while recording from the front panel jacks. This happens just sometimes, and it suddenly stops after a few minutes playing, coming back randomly. This is hardly noticeable unless I raise highs on my setup, but it sounds pretty clean when this noise stops and I'd love to have such clean sound always.

I'm sure it has to do something with grounding as whenever I touch the harp assembly/supports, this affects somewhat reducing/increasing such noise

It seems all cables are in place, every pickup screw is tightened, every soldering joint seems ok, I don't know what else to check
Any help?

[OZDOC]

Are you sure it's a problem in the Rhodes?
Are there any other appliances on in the house at the same time that could be inducing the noise?

[Cormac Long]

There's a general attempt on the rhodes wiring to ground the tone bars, pickup tangs and sustain bar.

This is achieved on the harp with the grounded aluminum strips that run along the pickup and tone bar rows. The pickups and tone bars make contact with this in an attempt to get grounded.

If you connect a multi meter in continuity mode (with the audio beep) between the RCA ground and any tone bar or pickup tang, you should measure a connection. I think you should find all pickup tangs connected and most tone bars have a grounding. The grounding connection for the tone bar is between the strip, spring and tone bar. Sometimes that connection is not perfect.

It seems that as long as its there for most tone bars then all should be fine. If a lot of them are missing the grounding, then you do experience more buzz.

Then another thing to check is if the sustain bar is grounded. A lot of models either came wired with this extra grounding or had it retrofitted.

If you grab some alligator clip cables from an electronics shop, you could hot wire some tests by adding test grounds between the RCA and sustain, frame and maybe some of the tone bars... it might help gauge if a difference can be observed.

It is correct that nearby appliances can interfere. I have a low voltage fluorescent lamp about 3 feet above my rhodes.... if on I will pick up buzzing. Some people used to line the inside of the harp cover with foil to add extra shielding. But I reckon that most of that was the result of older analogue synths that were notorious for electronic noise.

[Abraham]

thanks for your help guys...

I have spotted and fixed a connection causing some buzzing at the end of the rca cable to the front panel jack. Also I have found the damper bar is not grounded apparently, I have to check with a multimeter.

But also during my testing, I have noticed this "random noise" persists even while the jack is unplugged from the piano, so I guess it doesn't have to do with the piano at all...

[Ben Bove]

Yes sometimes if all the ground issues are solved on the piano, your home could have potential grounding problems.

I know at my house, all is fine during the day, and then in the evenings I was noticing grounding issues.  Apparently outside lights on the lawn were on the same circuit as the studio and weren't grounded   I was thinking "why is there a buzz always at night only!"