Pups and 50-60HZ/RF EMI hum

[greekdude]

Hello
Yesterday I did some tests under high gain, + wahwah + signal boost.
From Single coils I have only one : DMZ Blaze (mid pos - ibanez uv70p). My Humbuckers in those guitars : Ibanez uv70p (DMZ blazes), Ibanez arz800 (EMG 81/60), Carvin dc135 (DMZ SuperDist/Air Norton S), Kramer 210 (EMG 85/81). Results from the noisiest to the quietest:

1) DMZ Blaze-7 Single coil (as expected) - ibanez uv70p middle (pos 3)
2) combo DMZ Blaze-7 Single coil / coil split DMZ Blaze-7 bridge/neck - ibanez uv70p (pos 2,4) - I am writing this for the sake of comparison since this is considered a "humbucking position"
3) EMG 81 (very close to 2) - Kramer 210 neck
4) EMG 81 (almost identical to 3) - Ibanez arz800 bridge
5) EMG 60 - Ibanez arz800 neck
6) EMG 85 (close to 5)- Kramer 210 bridge
7) DMZ Super Distortion - Carvin dc135 bridge
8 ) DMZ Blaze-7 bridge - ibanez uv70p bridge
9) DMZ Blaze-7 neck - ibanez uv70p bridge
10) DMZ Air Norton S - Carvin dc135 neck

9, 10 are practically noiseless, no matter the conditions or the gain.

 

[DrNewcenstein]

Re: Pups and 50-60HZ/RF EMI hum

Given both active pickups in the low-end Kramer and Ibanez buzz, I'd say it's something else in the guitar, like control cavity shielding or maybe a weak ground. As well, the metal parts to which the pickups are grounded (jack and pots, etc) may be too cheap. Replacing them with quality components made of quality materials may help.

 

[greekdude]

Re: Pups and 50-60HZ/RF EMI hum

Given both active pickups in the low-end Kramer and Ibanez buzz, I'd say it's something else in the guitar, like control cavity shielding or maybe a weak ground. As well, the metal parts to which the pickups are grounded (jack and pots, etc) may be too cheap. Replacing them with quality components made of quality materials may help.

EMG says there is no need to connect the ground to the bridge. Grounding is good on both guitars as they sound excellent both clean and distorted provided I play them in another room (I do all the tests with a modelling effect pre-amp - no amp involved) or at a different time other than evenings/nights. EMG 85 on the kramer 210 is FAR LESS noisy than the 81 on the same guitar, it can't be the components. To me simply 81 (maybe from the pre-2010 era) use unbalanced inputs, the noise sensed by the 1st coil is not equal to the noise sensed by the other.
Also I see old EMG specs e.g. from here : http://www.musiciansfriend.com/accessories/emg-emg-81-humbucking-active-guitar-pickup , stating that output noise = -91 dBV . Whereas in the official site they state : http://www.emgpickups.com/media/productfile/h/_/h_b245_0230-0106re.pdf , output noise = -100 . The X version 81x looks even better at -105 . The Ibanez arz80 I bought new in 2012, pups write 2010 on them. The 85/81 I bought recently they are older, and write 2007 on them.
Maybe things have improved as of "late"?

 

[DrNewcenstein]

Re: Pups and 50-60HZ/RF EMI hum

Ok, if it's happening only in one room and/or only at a certain time of day, it's something in the room.

No matter how many grounds you run in a guitar, facing your rack, computer, or other electrical appliance with the guitar will cause this. If there's an electrical appliance in the room no matter which way you turn, there's the problem. A fan, the TV, the computer, and the lamp on the table, as well as the ceiling fan above you, will generate a field which your guitar is picking up. Condense everything to one side of the room or move some of it out so you have a "clean" wall to face and the noise will stop.

Also, the wiring in the building and anything else on that same circuit (dishwasher, washing machine, refrigerator, someone using a hair dryer in the next room, a toaster, the coffee pot, etc etc) will cause this.

 

[dotsdad]

Re: Pups and 50-60HZ/RF EMI hum

Ok, if it's happening only in one room and/or only at a certain time of day, it's something in the room.

No matter how many grounds you run in a guitar, facing your rack, computer, or other electrical appliance with the guitar will cause this. If there's an electrical appliance in the room no matter which way you turn, there's the problem. A fan, the TV, the computer, and the lamp on the table, as well as the ceiling fan above you, will generate a field which your guitar is picking up. Condense everything to one side of the room or move some of it out so you have a "clean" wall to face and the noise will stop.

Also, the wiring in the building and anything else on that same circuit (dishwasher, washing machine, refrigerator, someone using a hair dryer in the next room, a toaster, the coffee pot, etc etc) will cause this.

^^^ QFT ^^^

 

[greekdude]

Re: Pups and 50-60HZ/RF EMI hum

Just measured EMI yesterday night, magnetic field composite/resultant intensity was at 0.4uT at the problematic spot/problematic room, while it was close to 0.15uT at the less noisy room. Today morning it was 0.1uT and 0.04uT respectively. So from the less noisy room/spot/time to the most noisy room/spot/time it is 10 times difference. We have some wires from the public power lines running just 3 meters outside our balcony. My son's room next to this also has the same proximity to those lines. No wander my son does not want to sleep there.
We gotta do smth with this, and I don't know what is cheaper, to protect those two problematic rooms or change house.

 

[Darg1911]

Re: Pups and 50-60HZ/RF EMI hum

People do paint their walls with shielding paint. I have no idea how much that would reduce the emi from the power lines. I used to do some work in a subdivision where the back yard of all the homes at the back of the subdivision faced a field. Transmission lines on those big, metal tower/poles ran through the field, parallel to all those homes. There was also aerial communication plant, which is what I worked on. When you went back there you could not only hear the buzz but you could feel it. Not a shock, just like an internal sensation. You could hear the buzz and almost "feel" it as well. Hard to explain. All I remember thinking is that I would never want to live in those homes. Not the only place where I worked near transmission lines, but definitely the worst.

 

[greekdude]

Re: Pups and 50-60HZ/RF EMI hum

Thanx Darg. 0.4uT (=4mG) is the limit here in EU. It seems we are right on the legal limit with this. Shielding paint may help against RF/HF but now LF magnetic fields. I will check later at night, e.g. after 23:00 .