Hello! Owner of a 10 string Railboard here (about a year old) that I am running through a Line 6 Helix Floor unit. I get a slight buzz when using higher gain signal chains, always resolved by adjusting the cable. By "adjusting," I mean even the lightest bump generally resolves the issue. It's infrequent, but once it starts, it doesn't stop until I've nudged the cable.

I've ruled out: 1) the room (problem persists in multiple rooms in my home), 2) the cables (rotated through a few guitar cables as well as the stereo cable that comes w/ the Stick), 3) the input (I've tried the Guitar, Aux and a Return input on my Helix Floor ... while the Guitar input is hottest, the problem is present in all).

I think that means it must be the input jack on the instrument itself, no? I'm a little worried, trying to open the R-Block up and taking a look myself, but I think that's the next step. I'm posting in case anyone has any advice or thoughts based on what I just explained above - I don't really do much in the realm of electronics, but I'd imagine it would be pretty straight forward to see if something related to the input jack is loose and simply needs to be tightened ...

I should also say that I've dialed in noise gates to cut out the noisy floor that generally accompanies higher gain signal chains ... this bit of noise is definitely something else (louder, intermittent, etc), though.

The Railboard R-Block has no cover on the bottom. When you remove the two machine screws that fasten it to the board, you will see that it's wide open. The two ends that over hang the board have covers, but the main body of the R-Block has none. I removed my R-Block two days ago, when I was trying to figure out why the pickups had a limited amount of adjustment. I discovered that of the three adjustment points on each pickup, only one spring was used. There were rubber inserts on the other two. I modified my unit and installed a spring under each adjustment. I now have full control of how my pickup is adjusted. BTW - In order to remove the R-Block, you will need to remove all of the strings. I used 3 rubber bands, spaced out along the board to keep my strings in order and connected to the head end, while only disconnecting the bottom.

As for the buzz, if moving the cable fixes your issue, try installing a self adhesive cable holder to the back of your Railboard and looping the cable thru it as a strain relief. When I play my PRS Custom 24, I always loop the cable back thru the strap to prevent accidently unplugging it while playing.
https://www.amazon.ca/Yocice-Adhesive-O ... B07PS3X1LG

I appreciate the suggestions, WerkSpace - I'll likely add one of those cable holders, though I mostly play sitting down and that input jack is still pretty close to my leg. I suppose I could grab a right angle cable ... hmmmm. (Although I will say that last night I had an instance of "the buzz" starting and it began without any positional adjustments/bumping the cable/R-Block whatsoever. Ugh)

And thanks for the tips re: taking off the R-Block! I suspect I'll only need to remove the back plate on one side as opposed to removing the entire unit, but that's a good process to know nonetheless. Appreciated.

I deal with noise issues all the time. It might be just your house and interference. I went room to room like you did, but then I traveled to an AirBNB and took my stick and had nothing but glorious silence. Also if you are using the helix be mindful of the amp models you are using, and their settings. Gain staging in the software I have found to be kinda complicated. Just a couple suggestions, noise is such a pain to track down!

I think you overstated this. The strings need to be loosened, a lot, but not completely "removed"

I used a glasses case to prop them up. It was high enough and has a nice curvature to prevent the strings from getting kinked, when I swapped out the EMG module for my original Railboard R-Block.

Good suggestions, otherwise.