Sparky Mark Posted November 4 Share Posted November 4 Does any amount of bass guitar control cavity shielding actually stop a partially dimmed (dodgy?) dimmer switch from adding buzz to the signal? I played in a bar last weekend that had lights dimmed and I had to completely roll off the top end to hide the really, really annoying buzz. Only touching the metal control knobs stopped the buzz and fret hand tapping through the entire gig wasn't an option (even if I could do it). The one good thing was that it revealed the bridge, and therefore the strings on my Patrick Eggle New York IV bass weren't grounded. Yesterday I removed the bridge, scratched some paint off its underside where the ground wire was positioned, which fixed that issue. I've got a dimmer switch at home which has exactly the same effect on the basses I've tested. Anyone know whether there's a real fix, or does more cavity screening just improve things but not eliminate it please? Quote Link to comment Share on other sites More sharing options...
itu Posted November 4 Share Posted November 4 Is the dimmer for old bulbs or LEDs? Modern Schneider Exxact dimmer seems to work better than many other brands. If the dimming is flicker free, you should get less issues than with older phase cut systems. Shielding helps somewhat, but your pickups most probably are the window to buzz. You could try an age old pickup shield à la J bass (check M. Miller's natural J). 2 1 Quote Link to comment Share on other sites More sharing options...
SamIAm Posted November 4 Share Posted November 4 Not sure if cavity screening will totally resolve it, do you currently have any? Copper tape seems to work better IME then the black graphite paint. Another option (just for places with this problem) might be to wear an earthing strap and clip it to your bridge, they are used to ground bodies when working with electronics and should have the same effect as you touching a grounded bit of your bass. https://www.amazon.co.uk/Anti-Static-Wrist-Straps-Anti-Static/dp/B017164JG6/ Sam x 1 1 Quote Link to comment Share on other sites More sharing options...
Sparky Mark Posted November 4 Author Share Posted November 4 2 hours ago, itu said: Is the dimmer for old bulbs or LEDs? Modern Schneider Exxact dimmer seems to work better than many other brands. If the dimming is flicker free, you should get less issues than with older phase cut systems. Shielding helps somewhat, but your pickups most probably are the window to buzz. You could try an age old pickup shield à la J bass (check M. Miller's natural J). Definitely old fashioned dimmer at home, unsuitable for LEDs. The bar had those fashionable large filament bulbs, and a halogen spotlight right overhead that was flickering like a good'n. The cause of the issue was the bridge being isolated due to the paint on its underside. Both the cavity and pickguard are lined with aluminium foil giving a modicum of screening. I reckon I'm in contact with at least one string 99% of the time when playing (and standing around waiting for the next song to start) so now that's fixed I think I'll be OK in future. 2 Quote Link to comment Share on other sites More sharing options...
Sparky Mark Posted November 4 Author Share Posted November 4 2 hours ago, SamIAm said: Not sure if cavity screening will totally resolve it, do you currently have any? Copper tape seems to work better IME then the black graphite paint. Another option (just for places with this problem) might be to wear an earthing strap and clip it to your bridge, they are used to ground bodies when working with electronics and should have the same effect as you touching a grounded bit of your bass. https://www.amazon.co.uk/Anti-Static-Wrist-Straps-Anti-Static/dp/B017164JG6/ Sam x I've used those straps for soldering electronics in the past, but I'd be a bit nervous about permanently connecting myself to my amp, just in case something went wrong, connecting me to high voltages. At least with a guitar, there's a chance you can take your hands off when the tingling starts. 1 Quote Link to comment Share on other sites More sharing options...
rmorris Posted November 4 Share Posted November 4 58 minutes ago, Sparky Mark said: I've used those straps for soldering electronics in the past, but I'd be a bit nervous about permanently connecting myself to my amp, just in case something went wrong, connecting me to high voltages. At least with a guitar, there's a chance you can take your hands off when the tingling starts. The anti-static ground connection as used in electronic production environments usually has a high impedance resistor in line (eg 1 Meg Ohm) to avoid high currents but still negate charge build up. 2 1 Quote Link to comment Share on other sites More sharing options...
Sparky Mark Posted November 4 Author Share Posted November 4 4 minutes ago, rmorris said: The anti-static ground connection as used in electronic production environments usually has a high impedance resistor in line (eg 1 Meg Ohm) to avoid high currents but still negate charge build up. Do those straps work on the same principle as the small mains live detecting screw drivers? 1 Quote Link to comment Share on other sites More sharing options...
rmorris Posted November 5 Share Posted November 5 9 hours ago, Sparky Mark said: Do those straps work on the same principle as the small mains live detecting screw drivers? No 1 Quote Link to comment Share on other sites More sharing options...
prowla Posted November 5 Share Posted November 5 I sometimes get a buzzing if I'm at the (in)correct angle and my Lutron dimmer is on. It was particularly pronounced when I tried a Darkglass pedal, to the point that I returned it. I haven't noticed it of late (but probably will next time, because of this thread!). 2 Quote Link to comment Share on other sites More sharing options...
Sparky Mark Posted November 5 Author Share Posted November 5 11 hours ago, rmorris said: The anti-static ground connection as used in electronic production environments usually has a high impedance resistor in line (eg 1 Meg Ohm) to avoid high currents but still negate charge build up. A very small current passing through a heart (from plucking to fretting hand) can be fatal. 0.007 amps (7mA) passing through the heart for three seconds is enough to kill. Would that 1 Meg resistor limit current below that level? Quote Link to comment Share on other sites More sharing options...
nekomatic Posted November 6 Share Posted November 6 On 05/11/2024 at 08:24, Sparky Mark said: Would that 1 Meg resistor limit current below that level? To pass 7 mA through 1 Mohm you would need a voltage of 7 kV. 1 1 Quote Link to comment Share on other sites More sharing options...
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