sessylU wrote: ↑Fri Aug 11, 2023 3:42 am
OP: this is easy to test. Plug your bass in, set it down and walk away from it. Does the noise persist or go away?
That's not a great test. Even if you walk away, the air is still full of the same buzzy frequencies that our bodies conduct and reflect.
Did you ever have an old over-the-air TV antenna? Did you notice that often you could often get better reception just by standing near, and especially by touching the antenna? The human body is both conductive and capacitive; so the extremely over-simplified explanation is that when you touched that old TV antenna, you became part of it, making it bigger.
When you play your instrument and are
not grounded through the strings; you're an additional weird-shaped, noisy sort-of-antenna near the pickups.
When you
are grounded through the strings; you're an additional weird-shaped, now-grounded
shield near the pickups.
Here, I made a quick video to demonstrate:
https://imgur.com/a/sqTx4RG
(make sure you click the audio on)
Instrument cable into little practice amp. Even with my cellphone's crappy microphone off-axis from the speakers you can hear the buzz gets louder when my hand is near the tip. And when I touch the sleeve (ground) most of the buzz goes away, for I become a big weird-shaped shield near the tip.
Jack
P.S.: I love distortion pedals (especially Muffs) but as we all know, they massively amplify any extraneous noise that our pickups pick up...
So one of my pandemic projects in 2020 was testing different shielding methods with a pickup mounted in a little wooden box (well, there were three identical boxes throughout the experiment)... I tried copper tape, aluminum foil, MG Chemicals carbon spray paint, and MG Chemicals nickel spray paint... and for reducing buzz around a guitar pickup, all of them worked about equally well!
But what I found once I moved my experiment to a couple bottom of the barrel, $60 on Craigslist, Strat-style guitars was that
shielded or not, the player touching grounded strings reduced buzz
even more than any of the shielding methods... so now I don't bother to shield guitars anymore
...unless the player can't be added to the ground through the stings
Consider this all anecdotal, I'm not an electrical or RF engineer, so maybe I'm misinterpreting the data. My experiments were only
somewhat controlled, I didn't have an isolated laboratory to consistently repeat the exact frequencies that were in the air with each test; but all of the results were extremely consistent, in
my apartment, for
me. It's quite possible that shielding could be more effective than grounding the player through the strings in other environments.
(If I was smart, I would have video recorded every step and made a YouTube series out of it Jim Lill style... but I'm not smart)
tl;dr - If the player is isolated from the ground via tapewound strings, shielding the instrument will help, but not as much as adding the player to the ground would. Even with shielding, if you still get more buzz than you can stand, try different pickups; some pickups (especially "noiseless" ones) are a little less sensitive to buzz than others (and no, I'm not talking about humbuckers per se, 50/60Hz
hum is a different noise than
buzz).
)
