#881652 - 10/30/00 01:54 PM
SERIOUS Single Coil noise!!!
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micchip@yahoo.com
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Registered: 10/30/00
Posts: 3
Loc: Valley Stream,NY,UNITED STATES
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I am the house engineer at a club on Long Island, NY where we have shows about four times a week. I would say about half of them would be with a strat and some sort of tube amp. This past Saturday,10/28/2000, I had a national act in with a Strat / Twin reverb set up that we could not get quite no matter what we did, to the point where the show had to be called off. (In front of a sold out audience) I tried everything. He runs through a Tube Screamer pedal and into the amp. I moved the amplifier and guitar rig to 5 different buildings on the same block. I pulled the entire PA, Monitor rig and band powers ground and ran a New Isolated ground onto a large spike ran through the parking lot. tried atleast 10 different guitars through 6 diff. amplifiers all reaching the same result. As the main attraction of this artist is his guitar playing (and Sound) the crew was unwilling to change any gain structuring to achive a usable singnal. I even tried to shield the amplifier from noise by wrapping it in two dif. kinds of metal. I metered the ground to neutral on my DMM and there was nothing there. We tried powering the entire guitar system from the tour buses generator to isolate EVERYTHING from NY's power and no change at all with anything we did. There was approx. 10 - 15 proffesionals working on this for about 6 hours with no change at all. Please post ANY idea's on this as a re-schedule date is only two weeks away and a repeat is out of the question.
Thanks in advance,
Sal Sciacca (MicChip@yahoo.com)
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#881653 - 11/01/00 12:27 PM
Re: SERIOUS Single Coil noise!!!
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breakway@bellatlantic.net
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Registered: 06/25/00
Posts: 40
Loc: ,NJ,UNITED STATES
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Since you are the house person, what other guitar/amp combos are clean? You mention swapping guitars, what about cables? I have seen many Strats that are problems--it is not the electrical grounding of the venue. They pick radiated EMI from dimmers; electrical devices, ie, motors, compressors; and radio/tv signals. Lighting dimmers that are not loaded enough (ie, 500w on a 5k dimmer) exhibit noise spikes. Also, was he using a wireless?
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#881654 - 11/01/00 04:23 PM
Re: SERIOUS Single Coil noise!!!
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micchip@yahoo.com
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Registered: 10/30/00
Posts: 3
Loc: Valley Stream,NY,UNITED STATES
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I realize that the Strat/Tube amp combination is probably the worst noise rejecting we'll ever see. We did change cables many times as well as trying a wireless. Is anyone aware of who I might contact to get the building tested for EMI and other types of interference? The noise sounds like a switching occurring at much higher than 60 CPS. We did shut down all beer coolers, all lighting, all cell. phones and even a TRS wireless pager antenna near by the club all to no change at all. With the Twin Reverb plugged in alone you can hear it, add just a strat and there is a lot of noise (Not Directional like most pickup based stuff) Add a Tube Screamer and it is simply unplayable.
Thanks
Sal Sciacca (MicChip@yahoo.com)
12 days till reschedule date.
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#881655 - 11/02/00 12:00 PM
Re: SERIOUS Single Coil noise!!!
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Anonymous
Anonymous
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Check out emiguru.com for references for local emi testing firms. Call Bill or Darrel and they should get you connected.
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#881656 - 11/03/00 09:53 PM
Re: SERIOUS Single Coil noise!!!
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breakway@bellatlantic.net
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Registered: 06/25/00
Posts: 40
Loc: ,NJ,UNITED STATES
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Sal, I don't know what elso to tell you. The tube screamer seems to make it worse because of the high gain and compression. You need a guitar tech wizard, or more ideas to try. Maybe post your dilemma on Craig's Studio and Stage forum.
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#881657 - 12/15/00 06:47 AM
Re: SERIOUS Single Coil noise!!!
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nuisancecrew@hotmail.com
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Registered: 11/27/00
Posts: 17
Loc: ,,UNITED STATES
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Hey Sal, I Have been having exactly the same problem at my house. I set up a home recording studio, and found out that any combination of amp/guitar gives a horrible buzz. I've went through the same procedures (turned of power to whole house and ran off of a UPS) with no results. There are some power lines next to the house across the alley, the insulation on the wires is mostly gone and I'm wondering if they might be the culprit. I'm interested to hear what you find out, I plan to call the power company and see what they have to say. Hmmmm. I'll just have to start recording only acoustic and rap groups.
Jeremy Dallek
Seamless Media
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#881658 - 02/01/01 06:15 PM
Re: SERIOUS Single Coil noise!!!
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MidiMagic
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Registered: 02/01/01
Posts: 17
Loc: Bloomington,IN,UNITED STATES
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First of all, there is a simple test you can make to tell if the problem is related to the wiring in the guitar-amp combo or to induced noise in the guitar pickup:
1. Turn down the volume controls on the guitar.
2. If the noise is still there, then either the noise is being induced by the cord or the amp, or the guitar is defective.
3. Turn up the guitar to normal playing level.
4. Have the guitar player slowly turn around in a complete circle while holding the guitar.
5. If the noise increases and decreases, the guitar pickup is picking up ambient noise. If the noise remains steady, there is something wrong with the power or the signal lines.
Suggestions:
1. NEVER remove or defeat the grounding pin on a power cord. The death penalty (electrocution) awaits for those who do.
Grounding problems should always be taken care of in the signal lines, with ground loop isolators (Radio Shack has them) and the ground lift on direct boxes.
2. Sources for induced hum and buzz: Dimmers, fluorescent and discharge lights, neon signs, televisions, medical equipment, motors, fans, computers, wall-wart AC adaptors, fish tank pumps, and building wiring close to the instrument.
3. One often overlooked source of grief is a wall wart placed right next to a direct box. The transformer in the DI is all too happy to pick up the magnetic field from the power transformer in the wart.
4. Grounding is the most misunderstood thing in sound. Improper grounding that produces hum and noise results from one of five faults:
- a. An ungrounded item
- b. An unshielded cable (don't mix speaker and instrument cables)
- c. Too many grounds (ground loop)
- d. Induced pickup
- e. Different grounds (more than one supply panel)
5. One trick that often works is to plug everything into the SAME outlet, using power strips. This provides the common grounding point at the power strip (assuming that some chowderhead hasn't destroyed the grounding pins on the amps). If this would draw too much power for the circuit, then put the power amps on other circuits ON THE SAME BREAKER PANEL.
The ideal case (which I am about to implement in our venue) is to have one subpanel JUST for audio use, with no other loads on it.
6. Where pieces of equipment are plugged into two different circuits, it may be necessary to use ground loop isolating transformers to couple them.
7. If the guitar pickup is picking up extraneous noise, the following remedies should help:
- Change the pickup to a humbucking pickup.
- Place a flat steel shield under the pickup (on the side away from the strings). It should be much wider than the pickup, or folded around it. A piece of "tin" can will do (but not aluminum).
- Place a steel or iron plate between the offending source and the guitar (other metals will NOT work - you need a magnetic shield, not an electric one).
- Watch where you put wall-warts. Those may need to be shielded in stubborn cases.
8. If a dimmer turns out to be the culprit, the filters must be placed right at the source and load terminals of the dimmer. Otherwise, the cable is enough to radiate a lot of trash. Even with filters, some of them can change the waveform of the power at the service entrance, which then affects all circuits. If you have dimmers for fluorescent lamps, get rid of them. I have never been able to make clean recordings where they were in use.
One radical fix for this is to have a separate service entrance for stage lighting, with a separate meter (which acts as a filter).
9. It is possible that the trash is coming in on the power lines from another building on your distribution transformer, or even on the substation transformer. One good possibility is a stadium, factory, or parking lot with all discharge lighting.
10. If altering the gain structure fixes the problem, it indicates something wrong with the gain structure in the first place.
11. If your snake is not being run balanced line, change things so it is. That means the monitors too. It is worth it.
12. Never use a balanced/unbalanced converter or cable that does not have a transformer or an op-amp in it. The others pick up incredible amounts of noise.
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#881659 - 02/28/01 02:04 AM
Re: SERIOUS Single Coil noise!!!
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gigeditor
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Registered: 08/20/99
Posts: 27
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I ahd a similar problem years ago with a favorite Strat. I took it to a repair guy who wired another single-coil pickup out of phase between the volume pots and the output jack. This, in effect turned the who guitar into a giant humbucker without really affecting the tone. It's an old fix (I learned about it 20 plus years ago in an interview in Guitar Player), but it works.
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#881660 - 02/28/01 01:58 PM
Re: SERIOUS Single Coil noise!!!
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micchip@yahoo.com
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Registered: 10/30/00
Posts: 3
Loc: Valley Stream,NY,UNITED STATES
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Thanks for everybodys replies. The problem still exists, however unless the circumstances are right the problem does not show itself. The extra single coil inline but out of phase I have heard of but my problem is the guitar player (KWS) was walking in with his tour and app. 20 vintage strats and not one had the modification and altering one would probably be a sin. Anyway the only thing I have yet to try that I could think might be possible was the fact that I had the power company down and we metered the problem at approx. 60 Mhz. According to the FCC the only thing supposed to be in that range airborne is Channel 5 and Channel 6 television stations. When I took a portable TV with a sweepable tuning dial between 5 and 6 I could se a steady pattern on screen of what we were hearing coming from the pick up. With this set up I walked the property and it seemed to die in all cases within 100ft. of our building?¿? This problem still bothers me but that specific show WILL not happen. It could arise again with any other event we have as it is still there but the recipe must be right to be as apparent. The one thing I wanted to try but have not done yet was the act that being a sports club we have ALOT of cablevision and multiplexed video in house. As such I want to next explore the possibility that from either bad lines or open ended lines that we were the source of the broadcast. Garnted we did shut th power to the entire building but the lines coming in from the street were always still live. Well thats where I'm at these days with this.
Thanks again,
Sal Sciacca, NY
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#881661 - 03/07/01 07:07 PM
Re: SERIOUS Single Coil noise!!!
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MidiMagic
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Registered: 02/01/01
Posts: 17
Loc: Bloomington,IN,UNITED STATES
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Unterminated cable lines are a serious source of interference. So are older computers, or computers with covers missing.
NTSC TV signals have a SYNC BUZZ in their signal, with the frequencies being approximately 59.9 Hz and 15735 Hz. These are the frequencies that the vertical and horizontal sync spikes appear at in the signal.
Computers give off signals at the clock frequency and at all super and sub harmonics of that frequency.
Computer monitors give off sync buzz at frequencies similar to the ones for TV, but the exact frequencies depend on the video mode selected.
Business rated computers and peripherals are allowed to interfere more than consumer rated equipment is.
Newer equipment is not supposed to interfere with radio and TV reception, but it is not tested against professional sound equipment.
The little ferrite clamp-on interference choke that Radio Shack sells does wonders against this kind of interference.
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