Has anyone here tried the Y-Shield conductive paint?

[soundguruman]

I was tripping out listening to one of his live recordings thinking that the single coil noise added to the total effect of his sound- it just would not have sounded as good if the single coil noise wasn't there.

Steve

What a coincidence, I'm still tripping out.

[big_teee]

I thought I already mentioned this earlier in this thread but I live across the street from a big transformer from the electric company so that contributes to some of the noise. I had removed all of the dimmers from my condo a long time ago (I worked as an electrician for many years so I have checked that my outlets are all properly grounded. To add insult to injury the next door neighbor moved his TV cable outlet from the garage side of his condo to the wall right next to my music room. When his 42" LCD TV is on I get the capacitive noise that Steve Conner mentioned, which in part appears to be RF (radio frequency.) "So how can you hear radio frequencies?" The interaction between two frequencies in the audio or radio realms can result in signals which are the sum of the two frequencies and in signals which are the difference between two frequencies.

If shielding is without merit why do so many guitar mfgs shield the control and pickup cavities of their guitars? Why did Gibson go to the trouble of enclosing the controls of many Les Pauls in a metal can? IMO it really makes a difference if you are playing in one of those BARS FROM HELL with almost as many cheap dimmers as light fixtures- even worse if someone gave them the bright idea of running Christmas lights connected to dimmers throughout the bar for "atmosphere."

You have made a valid point: shielding will do nothing to remove inductively-coupled hum from single coil pickups.

Steve Ahola

EDIT In looking for a room that would be better for my guitars I have used a battery-powered amp to test the noise levels in different rooms of my condo with both humbuckers and sc pickups, thus eliminating any crap coming into an amp from the AC line as well as increasing the distance from my neighbor's TV. I am in the process of moving to a room which is less noisy.

You need to move!
Just Kidding!
T

[soundguruman]

I thought I already mentioned this earlier in this thread but I live across the street from a big transformer from the electric company so that contributes to some of the noise. I had removed all of the dimmers from my condo a long time ago (I worked as an electrician for many years so I have checked that my outlets are all properly grounded. To add insult to injury the next door neighbor moved his TV cable outlet from the garage side of his condo to the wall right next to my music room. When his 42" LCD TV is on I get the capacitive noise that Steve Conner mentioned, which in part appears to be RF (radio frequency.) "So how can you hear radio frequencies?" The interaction between two frequencies in the audio or radio realms can result in signals which are the sum of the two frequencies and in signals which are the difference between two frequencies.

If shielding is without merit why do so many guitar mfgs shield the control and pickup cavities of their guitars? Why did Gibson go to the trouble of enclosing the controls of many Les Pauls in a metal can? IMO it really makes a difference if you are playing in one of those BARS FROM HELL with almost as many cheap dimmers as light fixtures- even worse if someone gave them the bright idea of running Christmas lights connected to dimmers throughout the bar for "atmosphere."

You have made a valid point: shielding will do nothing to remove inductively-coupled hum from single coil pickups.

Steve Ahola

EDIT In looking for a room that would be better for my guitars I have used a battery-powered amp to test the noise levels in different rooms of my condo with both humbuckers and sc pickups, thus eliminating any crap coming into an amp from the AC line as well as increasing the distance from my neighbor's TV. I am in the process of moving to a room which is less noisy.

If it actually IS RFI, then this is what you want:
Palomar Engineers | RFI Kit

Try to deal with RFI in the power and go from there.

Power conditioners: fairly useless also. Unless you buy a real one for $20,000.

YES WE CAN put ferrite beads inside the guitar, inside the amp in the audio path, especially between the input jack and the first preamp stage.
AND on the power supply leads, AC cord, etc...
The beads do not interfere with the audio in any way. But they do kill the RF.

[Steve A.]

I had mentioned getting an isolation transformer. Nope- it is a line filter. The can says "EMI filter," the datasheet calls it an "RFI filter." So what is the correct name for noise which is transferred across the ether but is not electromagnetic? I usually just use the term "RF noise" although probably not correct technically. Another example- the noises picked up from a computer- or a digital thermometer! We're talking Mhz here so how can there be any audible artifacts? I can't explain them but I know they are there...

5VR7 TE Connectivity / Corcom | Mouser

Of course, the 5VR7 would handle only the noise transmitted on the electrical lines and do nothing for the noise "in the ether." Hey why not just call it ethernoise?

Steve Ahola

[Steve A.]

You need to move!
Just Kidding!
T

I figured how to get back at my damned neighbors: I am moving my work bench into what has been my music room- set up against the wall right where their TV is. So they get to hear me hammer and drill and saw to my heart's delight when they are trying to watch TV.

Steve

[Steve Conner]

Q: Hey Jim, where you gonna go with that buzz in your amp?
A: I said I'm going down Mexico way, ain't nobody gonna shield my control cavity.

Anything "transferred across the ether" is electromagnetic. The capacitive coupling we've been discussing is mostly electric with a hint of magnetic field, and the inductive coupling mostly magnetic field with a hint of electric, but they still fall under the heading of EM fields.

If you grab some radio waves out of the air and measure the amplitudes of the electric and magnetic components, you'll probably find them in the ratio of 377 ohms. This is the "impedance of free space", the optimum ratio for propagation over long distances, somewhat of a natural constant like pi.

Devices like transformers and lamp dimmers can generate fields of any impedance they like. If the impedance is much higher than 377, we would call it an electric field. Foil tape, conductive paint and so on would make a good job of stopping it.

Much lower than 377, we would call it magnetic, and it would get into our single-coil pickups regardless.

If it is much different to 377 in either direction, it is a reactive field, otherwise known as "near field" since it doesn't propagate efficiently.

[jrfrond]

You can decouple your AC lines, use RFI filters all over the place, and you STILL will not be able to limit every RFI and EMI source. Even if you were to shield your house with Mu-metal, and line your walls with grounded copper screen (i.e. create a Faraday cage), you STILL would have numerous INTERNAL sources of interference from every single electrical device around you, including that cell phone in your pocket. So, shield your guitars as necessary. As far as shielding paint goes, skip the house-grade stuff and go with this more serious alternative: Super Shield

[Bruce / Mission Amps]

If it actually IS RFI, then this is what you want:
Palomar Engineers | RFI Kit

Try to deal with RFI in the power and go from there.

Power conditioners: fairly useless also. Unless you buy a real one for $20,000.

YES WE CAN put ferrite beads inside the guitar, inside the amp in the audio path, especially between the input jack and the first preamp stage.
AND on the power supply leads, AC cord, etc...
The beads do not interfere with the audio in any way. But they do kill the RF.

Off topic but... Good Grief! I didn't know Palomar was even still in existence... talk about a flash back.

[Steve A.]

As far as shielding paint goes, skip the house-grade stuff and go with this more serious alternative: Super Shield

Does that work better on guitars than the carbon paint that Stew-Mac sells? Super Shield costs about ~$200 for a 900ml bottle- or ~$45 for a 12 oz aerosol can (which could be great for guitar builders.)
I usually use copper foil tape but I solder all of the seams first and then usually end up with a coating of 60-40 solder on the entire surface (so that Superman can't use his x-ray vision to reverse engineer my wiring harnesses! ) The StewMac conductive paint goes on a lot faster but the small bottles always dry up on me so when I need to use them again they are useless. [It would probably help if I put Saran Wrap on the top of bottle before screwing on the lid.]

Steve Ahola

P.S. Speaking Faraday cages they had one at Pacific Stereo's R&D facility for their Quadraflex line of stereo receivers back in the mid-70's; I thought it was really cool!

[Steve A.]

Guess what?

My neighbors moved out over the weekend and my music room is once again free from all of that crap. As they were moving out I saw that it was a plain old CRT TV that on the other side of my wall (I guess the flat screen was upstairs in one of the bedrooms.) I didn't realize that people still used CRT TV's anymore since they are such an energy hogs- I think that a flat screen TV might pay for itself in energy savings after 2-3 years and after that it is all gravy.

FWIW I have CFL bulbs throughout my condo and have not noticed any increase in "ethernoise" when they are turned on. I remember that it was those long fluorescent tubes that raised hell.

Steve Ahola

EDIT Darn- some of the "ethernoise" returned about an hour ago. I do live in a 4-plex so it could be from a neighbor on the other side. Another thought: the condo complex has underground power lines going to the buildings. I believe that the line is right outside the window of my current music room (a good reason to move it to another room which I am in the process of doing.)