A couple years ago I designed an outlet tester that used the human body as the relative 0V reference (not actually 0V).I hope your "irrelevant" earth ground is at least connected to earth ground, or whatever your Code is. If I were playing a guitar and it hummed strangely, I'd fear being part of an undetected fault; you are assuming the pickup is the only possible source of guitar noise. A human is a fairly large capacitor plate to everything nearby. If your balanced power is floating you may not have touched the wrong thing yet. If you've already answered this question please pardon me.
Apparently it's in all the vaccines too, funny though, the schematic is the same as a Boss distortion pedal.Something appears to have changed from your discussion. Some times things break, and sometime new sources of interference pop up... 5G anybody?
Apparently 5G interferes with aircraft avionics so they are still trying to sort that out.
Variacs..This is why they put various in the walls of studios. They are variable AC transformers that lower the voltage by turning it down.
I think it’s worth looking into what Ike is talking about just to rule it out although it does sound more like 60Hz related.I'm located in more of a suburban area. I haven't noticed any new cell towers or anything in the area. However, assuming something like that is the case, what's the solution? I'm already using an isolation transformer/balanced power supply.
Listen to the recording. That's no cell signal.Where are you located? If you are in the US or Canada, you could be picking up RF from newly deployed 600 MHz range cellular services. I have dealt with several studios that have had issues with this getting into condenser microphones and it wouldn't surprise me to see it getting into guitars. Are you in an urban area? If so have a look at nearby rooftops and see if they have new looking cell towers on them. The fact that the level stays the same when you move around the room does speak to something with broader coverage.
Here's an anecdote that I think is probably spot on for your situation. I was working as a tech at a major destination studio that was made up of a couple of wings of an estate. The native power condition in the area wasn't fabulous, but also not particularly bad. Never the less, the studio in question was entirely served by balanced power. It developed a buzz like the one you are describing. It was my job to figure out what was causing the interference and put an end to it. I set things up so that the studio was powered by an independent gas-powered generator. Then, got a Fender Precision bass that was known to be fairly sensitive to stray inductance and positioned it in the room for maximum buzz. I then proceeded to turn of the circuit breakers that served that wing one by one, beginning with the most logical ones: heating, AC, lighting, etc. None of these had any effect. I was finally down to one remaining breaker - for a bedroom at the other end of the wing. There was nothing in that room that should have been causing interference, but when I flipped the breaker, all went silent. I ran down to the other end of the building and peered into the room. There was a laptop computer with a charger plugged into the wall. I unplugged the laptop, turned the breaker back on, and the studio remained silent. What I learned from this was that noise induction is a LOT more insidious than I had previously thought. And that maybe a totally quiet studio was more of a mysterious blessing than one you count on in a premeditated way. The implication for you are that the EMI you are experiencing may have its origins in your neighbors house, or perhaps a local business.About 2 weeks ago I noticed a new guitar amplifier buzz in my studio. I have since tried multiple amp & guitar combinations and they all have this nasty buzz. We have dirty power in my area so I've been using a Furman P2400 AR & IT for balanced power or a Tripplite isolation transformer. This setup has been working great for the last 4 years, then 2 weeks ago this buzz started. Occasionally an amp will pick up a very faint radio signal too.
From what I understand, I shouldn't be getting any sort of power line interference with balanced power so I'm not sure what to look for next. Any ideas what could be causing a buzz when I'm using balanced power?
The buzz seems to be roughly around 1khz. It does go away when I turn down the guitar. I have moved the guitar all around the room and the buzz does not change like regular guitar buzz.
There are no power lines or anything obvious that could be causing enough EMF/RFI that would cause this buzz. I have disconnected everything one the circuit other than the guitar amp and the buzz is still there.
The OP mentioned a new guitar amp noise but did not mention what guitar amp.
Some old school guitar amps with two wire line cords used stinger caps to "ground" (cough) the amp chassis cap coupled to the presumably quiet neutral. With balanced power that neutral will not be very quiet, but that would cause hum not buzz, so never mind.
I just did. It's not the "Morse code" DTMF tones that you will often hear if someone has a phone sitting on sensitive electronics and they get a call, text etc. but the noise that the new cell services cause, at least in condenser mics, doesn't sound like that either. I can't think of a good way to characterize the sound that I was hearing from the condenser mics, but when you think about it, the fact that an RF signal that is being transmitted at between 618 and 650 MHz (in 5 MHz swaths, no less) is coming out of a device that lives in the 20 Hz - 20KHz range, all bets are off as to what that will be demodulated as.Listen to the recording. That's no cell signal.
in France, last remnants of balanced 2x110V were replaced with the standard unbalanced 220 (now 230 Eurovoltage) in the early 70's.The European system is clean because it's balanced
At least in UK, France, Germany and Italy. I've read about horror stories in Scandinavia; in some places, the soil is hard stone, so the earth tag on sockets is strapped to neutral.and has a clean ground.