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Post by pete12345 on Oct 25, 2008 8:06:19 GMT -5
Hi all.
Since I've moved to uni, I've noticed my guitar makes an annoying, noisy buzz that I've never found before. It tends to go away if I turn down the tone controls, but then of course the guitar sounds like mud.
I was wondering if it was the lighting here, but I tried again this morning with the lights off and it's still there.
So... any thoughts on what's causing the hum? The two things that spring to mind are bad grounding (hope not) or just a higher level of noise that shows up through my poor quality shielding job. Any other ideas?
Pete
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Post by andy on Oct 25, 2008 9:40:09 GMT -5
That wouldn't be Surrey Uni would it? I've played there a couple of times.
As for the mystery hum, I've had it from electrics in the walls, but I should imagine the shielding should sort that sort of thing. Of course, cables and pedals can pick noise up too. I'm sure someone with a better idea will be along soon...
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Post by ChrisK on Oct 25, 2008 10:47:43 GMT -5
Do you have any idea as to the frequencies (or notes if one prefers) picked up? For instance, if the fundamental is lower that a guitar can go, it's likely the mains. You indicate that the tone control helps so it's likely a much higher frequency band. How many switching power supplies are in the room? These are found in computers, monitors, cell phone chargers, etc. Does the noise vary as the guitar's attitude (spatial orientation) is varied. Is the noise constant or time of day dependent? Is your room located above a high energy physics research lab?  |
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Post by pete12345 on Oct 25, 2008 12:16:05 GMT -5
Andy: Yep, University of Surrey  Do you have any idea as to the frequencies (or notes if one prefers) picked up? Not entirely sure, but it seems to be something between low F and F#. Guess it's not the mains then... I have my laptop and phone charger in the same room, but they're switched off when I'm guitaring. It's more noticeable through my effects pedal (Zoom 606) but that's always picked up a little bit of hum. Seems pretty constant from what I've found. Humm... so that's what the guy on the ground floor's been up to...  I may have to and redo my shielding job anyway- last time I made a fairly rough job of it, and theres a few holes in it here and there that probably don't help things. I used aluminium foil last time, is any other material better? Pete |
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Post by ChrisK on Oct 25, 2008 12:42:11 GMT -5
Yes, use unobtainium. Or at least copper, which can be soldered thus ensuring that all pieces are electrically connected to each other (at least at every 2" distance (5 cm) along each seam). I know that the Brits still understand inches, you secretly still use them when the French aren't looking. The public use of miles is just a clever distraction. F or F#, hmmm, would you believe G? Why, well, the inter-note spacing on the equally tempered scale is the 12th root of 2 or 1.0594630943592952645618252949463 F# is 9 steps above A (55 Hz) or 92.5 Hz (approximately) G is 97.998858995437323521424882614956 Hz or approximately 98 Hz. Your mains frequency is 50 Hz (life goes slower over there). Twice that is 100 Hz. Twice that is also the resultant base frequency of full-wave AC rectification of 50 Hz. Most switching power supplies (and possibly fluorescent light fixtures) cause interference thereat. Unless power factor correction (incorrectly called third harmonic reduction) is afoot, the narrow current conduction angle spawns harmonics abundant. |
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Post by ChrisK on Oct 25, 2008 12:44:02 GMT -5
Now, before you get too enthralled with Buzzing at University, in the U.S. at least, driving buzzed is still driving drunk......... |
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Post by andy on Nov 8, 2008 7:24:40 GMT -5
Andy: Yep, University of Surrey Cool, they have a great campus there. It looks like I'll be passing through there again on tour in a few months, so if you're still there by then, I'll drop you a line!  |
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