Recording studio 60hz noise

[ggunn]

I feel your pain. There is a run of medium voltage distribution lines alongside my house and my studio is in the garage on the side of the house closest to the lines. Single coil pickups through a high gain amp and/or distortion and overdrive howl like banshees if I stand holding the guitar parallel to those lines. Dynamic mics are not so bad, but the noise is there if I listen closely. I had the utility company come out with their gaussmeter, and they confirmed that the lines are the source of the noise, but there is nothing they can do about it.

Grounding won't help. Power conditioning won't help. Running off a UPS won't help. Balanced lines and cavity shielding do help somewhat, but the components at the end of the cables and the faces of the pickups are exposed to the noise and pick it up no matter what. The middle pickup on my Strat is RWRP, so in the #2 and #4 positions the noise is greatly diminished.

I do what I can, but what's left I just have to live with.

 

[cuba_pete]

SWER?

SWER?

This house is 120V only- no split phase.

Is this a SWER system? How do you know you do not have split phase power? Out of curiosity, how many circuits are in your panel?

I would delve into how your UPS and other electronics are connected on this "single phase" power. Is the UPS a true-sine unit? What frequency is the buzz? What frequency is the UPS converter? Is it a double or single conversion UPS?

Any source of noise coming from switch mode power supplies (even the UPS) in your studio needs addressing.

 

[jhammer619]

Is this a SWER system? How do you know you do not have split phase power? Out of curiosity, how many circuits are in your panel?

I would delve into how your UPS and other electronics are connected on this "single phase" power. Is the UPS a true-sine unit? What frequency is the buzz? What frequency is the UPS converter? Is it a double or single conversion UPS?

Any source of noise coming from switch mode power supplies (even the UPS) in your studio needs addressing.

I'm pretty sure this is not a SWER system- I'm in the city.

I have a 120V system (not split phase) because there are only 2 wires entering the house from the utility pole. The main disconnect has two 30 amp fuses- a fused hot and a fused neutral:happyyes:

This feeds a subpanel with 3 circuits if I remember right.

It is a plug-in type, true sine wave UPS, double conversion. I tried "sniffing" noise using the vulnerable mic and moving it toward the UPS, computer, and other power supplies. Those equipment do emit some magnetic interference but only when I get extremely close to them. (UPS units are supposedly notorious for EMI). The main culprit is the current drawn by these devices, running through the wiring in the attic. The neutral and hot conductors are something like 6 ft apart up there (K&T wiring) so I think we've pinned down the problem (not that I can do a whole lot about it, but it feels good to understand why!).

I ran an extension cord that's plugged into a different circuit (wiring that doesn't go over the studio) and the noise is significantly reduced! It doesn't disappear as much as when I hit the main disconnect (running off battery), but it's still a major improvement. If I move the mic to within 2 inches of that extension cord, I can find the noise again. The hot/neutral being ran close together cancels the magnetic fields, and this is something I've always taken for granted in previous spaces.

Thanks for all the insight and musicians' sympathy! I think we've gotten to the bottom of it. Hopefully this provides some examples of pitfalls to look out for in the future when building recording studios.

 

[ActionDave]

Is this a SWER system? .....

Can't be. Not available in the States.

 

[mgookin]

...- what is the proper way to wire a music recording studio ....
.

Start with a decent service. If this is a profession, that's something you may want to consider a higher priority on the next place you locate at.

 

[Gary Glaenzer]

If it is wired like a lot of K-T wiring, the 'hot' and neutrals may not even be close to each other, in fact they may take totally separate paths back to the service entrance.

In that case you have a (insert dimensions of the space here) single-turn transformer primary creating a large field, for whicch your microphones and guitar pick-ups provide a secondary.

Just my $ 0.02..................your mileage may vary.

 

[cuba_pete]

can't be

can't be

Can't be. Not available in the States.

I wouldn't have expected to find single phase with a fused neutral in the states either...but there it is.

 

[donaldelectrician]

I wouldn't have expected to find single phase with a fused neutral in the states either...but there it is.

Yes , a fused Neutral was used in the early yeas . I have removed a 16 circuit ? , fuse pan , with all circuit neutrals fused as were the hots fused .
House was built in the 1903 range . Panel was still in great shape .




Don

 

[Barbqranch]

Back in the late 60s, I had a friend who rented a house w/ a fused neutral. I suggested he take a (then fully copper) penny and put behind the neutral fuse to fix it. I don't know if he did. A (then silver) dime would have perhaps been better, but, you know, we were poor college students!

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[donaldelectrician]

Back in the late 60s, I had a friend who rented a house w/ a fused neutral. I suggested he take a (then fully copper) penny and put behind the neutral fuse to fix it. I don't know if he did. A (then silver) dime would have perhaps been better, but, you know, we were poor college students! ]

The coin is installed Heads Up I believe for better connectivity . Any Old Timers hear of this .




Don

 

[GoldDigger]

The coin is installed Heads Up I believe for better connectivity . Any Old Timers hear of this .
Don

I am not an old timer, but I think that the head side (obverse) of the Lincoln penny is smoother and raised in the center where the contact of the plug fuse would hit, compared to the rougher surface of the center of the reverse side.

 

[jhammer619]

If it is wired like a lot of K-T wiring, the 'hot' and neutrals may not even be close to each other, in fact they may take totally separate paths back to the service entrance.

In that case you have a (insert dimensions of the space here) single-turn transformer primary creating a large field, for whicch your microphones and guitar pick-ups provide a secondary.

Just my $ 0.02..................your mileage may vary.

This is most certainly the cause of my woes. I hit the main disconnect (and run off backup power, an isolated circuit) when my roomate's not home to get a less noisy single coil guitar :thumbsup:

Yea this is the only house on the block with original wiring I'd bet- slumlords! :lol:

here's the subpanel- I believe there are 3 circuits, each with fused neutrals- correct me if I'm wrong... And if that's the case, one of the circuits has a different amp fuse for the neutral than the line! That little xfmr is for the doorbell on the opposite side of the wall (this subpanel is located above a doorway in the waterheater/laundry room).

 

[GoldDigger]

That little xfmr is for the doorbell on the opposite side of the wall (this subpanel is located above a doorway in the waterheater/laundry room).

Putting the doorbell primary wires under the same screws as the branch circuit wires is probably not allowed, and the workmanship of that connection is abominable.

 

[PetrosA]

I've seen hundreds of doorbell transformers connected to the same breaker as some other circuit, so that doesn't bother me anywhere near as much as seeing all those 20 and 30 amp fuses and 14 gauge wire