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Tube amp mystery buzz
Old 28th July 2020
  #1
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Tube amp mystery buzz

Hi all, first time poster here.

I recently moved from the UK to Spain and am having issues with high-pitch buzzing from my amps (Traynor YGM3 and a Fender Champ). The noise is exactly the same for each amp (see attached for a sample).

The specifics:
  • It only happens when a guitar is plugged in (direct - no pedals or anything) and the volume is up. I tried a cheap Yamaha PSS something keyboard and, although it was very hissy (the jack output was added to the keyboard), it did not produce the same high-pitch sound as with my guitars.
  • I have had both amps checked by an excellent tech, and neither has the buzz in his shop. The tubes are all balanced and working nicely. I have tried with multiple guitars and cables to no avail.
  • My tech suggested a grounding issue in my building, so I had an electrician come (who also, strangely, knows a bit about amps as he built one for his son). The grounding is fine in the apartment. He did mention something about single phase/3 phase power and that there is no 'neutral' in my building - I don't know what that means or whether that is the cause, but it can't be changed.
  • I have turned off and unplugged ALL electrics in the flat, also turning off air conditioning etc. at the trip switch. It does not make a difference where I stand or where I position the amps. I also have a Belkin surge protector that filters EMI/RFI.

Nothing makes a difference, the sound doesn't change in the slightest. I am completely at a loss with this and it's beginning to worry me as it is making recording almost impossible. I'm actually considering getting a solar-powered generator so I have some clean power for when I'm recording.

Please help!
Attached Files

Traynor Buzz.m4a (197.5 KB, 169 views)

Old 28th July 2020
  #2
Gear Head
 
FlameTop's Avatar
That comment about having no Neutral seems worrying to me. I found this quote on reddit on a thread from someone reporting much the same noise as you get:

Quote:
Read this useful Sound on Sound article. One source of hum/buzz: single-coil pickups pick up the radiated field from your wiring - this radiated field is extra-high if:

Electrical neutral and ground are connected other than at the service entrance -- like old tube gear where neutral is bonded to the case, if this is connected to other gear where ground is connected to safety ground. People will sometimes make a "grounded" outlet by connecting neutral to ground at the outlet, or running a separate ground wire to some random ground, like building steel or water pipes -- it really needs to be in the same conduit or cable all the way back to the service panel, or you will get elevated EMC.

Neutrals from one circuit are connected to neutrals from another circuit.

Neutrals and hot conductors are not run together - the EMF-cancelling function of the "return" current doesn't work. Common in some methods of wiring lights to run from 2 or more switch locations, and in "knob and tube" wiring.

Some light dimmers cause problems

In short, some houses are just more "hummy" than others, a lot of this can be fixed, but it can be a mystery to find where things like connected neutrals might be happening.
(full thread here
https://www.reddit.com/r/audioengine...my_guitar_amp/)
Old 28th July 2020
  #3
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Quote:
Originally Posted by FlameTop View Post
That comment about having no Neutral seems worrying to me. I found this quote on reddit on a thread from someone reporting much the same noise as you get:



(full thread here
https://www.reddit.com/r/audioengine...my_guitar_amp/)
Thanks for the reply FlameTop.

I'm not really sure what all that means. "People will sometimes make a "grounded" outlet by connecting neutral to ground at the outlet, or running a separate ground wire to some random ground, like building steel or water pipes -- it really needs to be in the same conduit or cable all the way back to the service panel, or you will get elevated EMC." - Does this mean there is something I could to to stop this? Wiring up a power supply exclusively for my rig?

I have found that the noise persists if I plug my guitars straight into my audio interface, so it could well be the pickups picking it up, but I'm a tele man - I don't wanna give up my single coils!

I do have lights wired to multiple switches (e.g. hall lights can be turned on/off from either end of the hall)...
Old 28th July 2020
  #4
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juiseman's Avatar
turn off all the lights and anything else in the area like appliances.

I had noise from LED and CLF light bulbs, regular incandescent was fine..

does your guitar have extra foil shield in the pick guard area (bottom and top) this can sometimes help..
Old 28th July 2020
  #5
Gear Head
 
FlameTop's Avatar
It sounds like it is just RF being picked up by the single coil pickups. As you say you have tried to turn everything in your flat off, it may be its not even your circuit causing it. Things like cheap light dimmer switches can radiate like hell. Do you have any humbucker equipped guitars? If they are pretty quiet it would confirm its radiated IF thats the problem rather than a problem with the wiring supply. If you wave your single coils around, can you sense where it gets louder or quieter? It may a a neighbors switch that is the problem.
Old 28th July 2020
  #6
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enorbet2's Avatar
If the problem is in the electricity supply not being grounded (very serious issue for far more than just noise) at least you can protect yourself with a 1:1 center tapped isolation transformer if not by contacting your landlord, seller, or local authorities to fix what could actually be dangerous.
Old 28th July 2020
  #7
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Quote:
Originally Posted by FlameTop View Post
It sounds like it is just RF being picked up by the single coil pickups. As you say you have tried to turn everything in your flat off, it may be its not even your circuit causing it. Things like cheap light dimmer switches can radiate like hell. Do you have any humbucker equipped guitars? If they are pretty quiet it would confirm its radiated IF thats the problem rather than a problem with the wiring supply. If you wave your single coils around, can you sense where it gets louder or quieter? It may a a neighbors switch that is the problem.
I don't have any humbucker action at all. Moving the guitars/amps has no impact on the sound.
Old 28th July 2020
  #8
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Quote:
Originally Posted by enorbet2 View Post
If the problem is in the electricity supply not being grounded (very serious issue for far more than just noise) at least you can protect yourself with a 1:1 center tapped isolation transformer if not by contacting your landlord, seller, or local authorities to fix what could actually be dangerous.
I am getting the grounding fixed for the whole building, which is great health-wise but doesn't solve the buzzing.
Old 28th July 2020
  #9
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Quote:
Originally Posted by juiseman View Post
turn off all the lights and anything else in the area like appliances.

I had noise from LED and CLF light bulbs, regular incandescent was fine..

does your guitar have extra foil shield in the pick guard area (bottom and top) this can sometimes help..
I had absolutely everything turned off. I don't have any foil shielding in the cavities so I could give that a try, but I have never needed it before.
Old 30th July 2020
  #10
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enorbet2's Avatar
Quote:
Originally Posted by Greid View Post
I am getting the grounding fixed for the whole building, which is great health-wise but doesn't solve the buzzing.
I don't understand. The word "getting" leads me to think it has not happened yet so how do you assert no solution?

Look. The Input Jack on virtually every instrument amplifier has a built in switch that keeps the Hot side grounded when nothing is plugged in. That switch is automatically opened by plugging in, allowing signal to be amplified by the first stage of gain, whether the signal is music or noise.

Since you've apparently had a reputable tech check your amp and found no faults nor experienced noise as you do at home, the highest probability is bad power, either really "dirty" or more likely, badly grounded as possibly alluded to by the "no neutral" electrician.

If your house current has yet to be repaired properly, it isn't justified to judge yet.
Old 5th August 2020
  #11
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Quote:
Originally Posted by enorbet2 View Post
I don't understand. The word "getting" leads me to think it has not happened yet so how do you assert no solution?

Look. The Input Jack on virtually every instrument amplifier has a built in switch that keeps the Hot side grounded when nothing is plugged in. That switch is automatically opened by plugging in, allowing signal to be amplified by the first stage of gain, whether the signal is music or noise.

Since you've apparently had a reputable tech check your amp and found no faults nor experienced noise as you do at home, the highest probability is bad power, either really "dirty" or more likely, badly grounded as possibly alluded to by the "no neutral" electrician.

If your house current has yet to be repaired properly, it isn't justified to judge yet.
The electricians grounded the building and my flat as a test to see if that was the issue and it didn’t make a difference.
Old 5th August 2020
  #12
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enorbet2's Avatar
OK but the very fact that you get no noise at your tech's location but do get it at yours, is definitive evidence that something is not right in the power at your house. It is apparently the single difference in "the equation". Did your electricians check to see if there was a solid connection to the newly grounded building AT YOUR OUTLET?
Old 6th August 2020
  #13
Quote:
Originally Posted by Greid View Post
The electricians grounded the building and my flat as a test to see if that was the issue and it didn’t make a difference.
Really?:

Then they didn't do a very good job.... OR the line transformer on the pole could be bad.

Did you observe what they did to ground your building? If it was the same crew who wired it in the first place I'd question their competence.
Old 13th August 2020
  #14
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Quote:
Originally Posted by John Eppstein View Post
Really?:

Then they didn't do a very good job.... OR the line transformer on the pole could be bad.

Did you observe what they did to ground your building? If it was the same crew who wired it in the first place I'd question their competence.
They connected my apartment’s electricity to the metalwork for the elevator, which is fully grounded. The building was constructed in the 50s so I doubt it was the same guy!
Old 14th August 2020
  #15
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enorbet2's Avatar
The problem is still obviously in the power system for whatever reason or your amp would not work properly noiselessly anywhere.

So, get something like the below pictured 1000 Watt isolation transformer (~$60-$90 USD) and use the setting that only isolates, 1:1, not 1:2. or 2:1. It makes it's own Local and isolated, Ground.



Hopefully it's obvious that you need a version that complies with the supplied voltage and connectors in your country.
Old 14th August 2020
  #16
Quote:
Originally Posted by Greid View Post
They connected my apartment’s electricity to the metalwork for the elevator, which is fully grounded. The building was constructed in the 50s so I doubt it was the same guy!


And that's WAAAYYY wrong. In fact that's as likely to inject MORE noise into the system as to reduce it - probably more.

Elevators run off of very large electric motors. Such motors are MAJOR sources of environmental noise, ESPECIALLY in older buildings. Using the elevator hardware as a ground point could easily be injecting noise off the motor ground right into the house wiring.

A proper ground connection requires a 10 foot long copper stake buried about 5 feet below the surface. Only ONE ground.

Try to find some electricians who are not dummies. If you're in a city, call a local sound company for suggestions.
Old 14th August 2020
  #17
Quote:
Originally Posted by enorbet2 View Post
The problem is still obviously in the power system for whatever reason or your amp would not work properly noiselessly anywhere.

So, get something like the below pictured 1000 Watt isolation transformer (~$60-$90 USD) and use the setting that only isolates, 1:1, not 1:2. or 2:1. It makes it's own Local and isolated, Ground.



Hopefully it's obvious that you need a version that complies with the supplied voltage and connectors in your country.
Good idea. Do you know that's actually a transformer? There are a lot of electronic circuit designs that don't actually have a real transformer and may not provide full isolation.
Old 14th August 2020
  #18
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enorbet2's Avatar
Quote:
Originally Posted by John Eppstein View Post
Good idea. Do you know that's actually a transformer? There are a lot of electronic circuit designs that don't actually have a real transformer and may not provide full isolation.
True and I'm not certain that exact brand/model is transformer based, so good point. Anyone considering such an isolation device should inquire about that specific point - ie: whether full isolation is provided or not.

It was just a suggestion and a quick generic example as I'd never buy a commercial product like that. I'd just order an isolation transformer, probably from Newark, and build my own.
Old 15th August 2020
  #19
Quote:
Originally Posted by enorbet2 View Post
True and I'm not certain that exact brand/model is transformer based, so good point. Anyone considering such an isolation device should inquire about that specific point - ie: whether full isolation is provided or not.

It was just a suggestion and a quick generic example as I'd never buy a commercial product like that. I'd just order an isolation transformer, probably from Newark, and build my own.
Yeah, me too!
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