Guitar/Bass noise problems

[ST.]

This is my first time posting a thread here. I hope I'm not breaking any rules.
EDIT 1: File is now attached. 2012/01/04
EDIT 2: Added clarification following Henrf's questions. 2012/01/05
EDIT 3: Tried battery powered amp, modded bass guitar. Bass mod includes: Foil in control and pickup cavities as well as the undersides of the control plate, pickguard, pickup covers and bridgeplate and a .022uf cap in line with ground lead to bridgeplate. No solder has been added between separate sections of copper foil. 2012/1/16
EDIT 4: Fixed problem! liberal amounts of copper foil seems to have done the trick. In my apartment, I still get some noise (which is probably caused by close proximity to neighbors). In my home, I get beautiful silence. Thanks to everyone who helped out. I hope that this thread can help anyone else with similar noise problems in the future. 2012/1/24

My problem:
I am experiencing guitar/bass noise. Unfortunately, it's not a usual hum/buzz issue. I suspect it's some kind of EMI/RFI interference, but I'm really not sure as I'm not really familiar with that kind of noise. It almost sounds like the high pitched noise that comes from a TV, but really amplified. The problem has been greatly reduced after adding copper foil to bass. The noise is still apparent on extreme amp settings (volume/treble@10) and I suspect my sloppy work to be the culprit. I want to try to find out what I can do to troubleshoot for problems and reduce the noise as much as I possibly can.

I want to be able to record DI bass and the occasional DI guitar at home. I currently live in Japan, but am from California. I had never experienced this kind of noise in California. It's like a very high pitched sound that comes in and out of my signal (but only with guitars & basses). I experience the problem at my apartment as well as my house. I do not experience the problem at my tracking room, even with the exact same equipment.


What I have done (with/without any success):
-I put a .022uf cap in line with the ground lead to my bridge. (I rewired the ground on my bass guitar.)
-I have tried different amps. (including a battery powered amp; the noise still persisted)
-I have tried different guitars (none of them are shielded, they only have single coil pickups)
-Since the noise was there with the battery powered amp the following is N/A: I have tried a tripplite isolation transformer with different equipment.
-I have tried different DI's.
-I have tried different preamps (from cheap to expensive)
-I have tried different converters.
-I have tried turning off the lights.
-I have tried shutting circuit breakers off.
-Since the noise was there with the battery powered amp the following is N/A: I have tried different power conditioners (including a Monster 2500)
-Since the noise was there with the battery powered amp the following is N/A: I have had my apartment outlet I use for audio replaced with a grounded, 3-prong outlet (my Monster 2500 indicates that there is ground).
-I have tried balanced and unbalanced cables.
-I have tried short (1 meter) cables and longer cables.
-I have tried different DAWs.

Like I said, regardless of any factor, I have never experienced this in California. Neither have I ever experienced this problem in my tracking room (which is located in Japan about 20 miles from my apartment). This problem is particular to my house and apartment.

What I suspect the most:
RFI/EMI noise
Wireless router interference. (Plan to test week of 1/16 ~ 1/22 @ home. Will update with results.)
Interference from things like refrigerators etc. from other rooms.

Just in case:
-I don't experience this problem at all with any other instruments or outboard gear. I have experienced this with an older TV and a Nintendo Famicom in my apartment. I have not experienced this with any dynamic microphones.
-I can use a gate to shut it up while I'm not playing anything, but the noise overpowers the signal whenever the gate is released.
-The noise does not come in and out at regular intervals. It does come in and out at irregular intervals.
-My house and apartment are in the same city about 5-8 miles apart.

I have attached an MP3 file (about 10MB) with the problem.

Here is the signal chain:
1. Fender Jazz Bass (noiseless cobalt samarium fender jazz pickups)
2. Canare TS 1M cable
3. Vintech 573 (lunchbox)
4. Canare XLR->TRS
5. Ferrofish A16 MKII
6. Monster Fiber Optic Cable (I think 2 or 3 meters?)
7. RME RayDAT

About the attachment:

The first segment is me going through different tone settings, starting at zero and ending at totally open. At the end of each clip I kind of let go and let whatever is happening do its thing. The last one is me touching different metallic parts of my bass to see if anything happens. In fact, most of the time I touch something a some of the sound goes away. As you can tell, however, the very end of the last clip is extremely annoying. What I am doing is touching the bridge pickup poles. Unfortunately, if I attenuate the bridge pickup altogether, the sound doesn't go away though!

The tone on my bass is all the way down at the beginning of the clip, which is why the annoying sound is less apparent. As the tone is raised, the sound becomes more apparent.

*****Caution:*****
Before anyone listens to the clips, I want to warn you that the noise is EXTREMELY annoying and high pitched. I would be weary of trying to listen with headphones right away. I would also lower the level as far as you can when you start playing the file and gradually raise it up just to get an idea.

PS: I have contacted some dealers for help, but haven't resolved the problem.

If anyone has had experience with this please let me know. If you have any ideas about how to solve the issue, I would love to hear them. If anyone else has this problem, let's try to solve it!

Thank you in advance

[ST.]

I just wanted to point out that I added the MP3 attachment I referred to in my initial post.

[Jim Williams]

RF in Japan is different than here in California, it's more congested.

You will need to screen the bass to eliminate that. Touching the pole magnets is a clue. Fender will sometimes wrap their pickups with the inside coil assigned as the "hot" lead. That helps those unsheilded pickups from going crazy with buzz pickup on the outside coil. You can reverse the wiring to those pickups to change the inside coil to the ground connection on the pickup. Then that noise pickup should go down quite a bit. Also, place a piece of electric tape across the pickups so you don't touch those magnets.

The rest is copper foil tape lining the entire insides of the bass, under and the sides of the pickup cavities too. Ground each piece. If you are carefull, you can also stick it inside the black pickup covers, that really helps. Lastly, check the string ground from the bridge, it should have a wire soldered to ground. Lift that and add a .022 uf cap in series with that wire. That way you won't get shocked from badly grounded sound systems.

[Ngr]

GuitarNuts.com - Shielding a Strat(tm)

check this, the procedure can be easily applied to a bass

[ST.]

Jim Williams, I appreciate your advice very much. Out of curiosity, have you experienced this problem in Japan before? I'm a little interested in knowing about what causes the congestion here you spoke of.

Incidentally, I had recently taken my j-bass in to see if a proper grounding would do the trick. I also asked to replace all of the wires for good measure... I paid good money for a whole lot of nothing. One of the first things I checked was the bridge plate ground, like you mentioned, and the wire was not soldered to it.

I just want to clarify a few things about your suggestion as I am very much a beginner when it comes to electronics.

- When you say wire a .022 uf cap in series with the bridge ground, I should just cut the wire a little short, solder on the cap, and add enough slack back to the other end of the cap to solder to the bridge, right?

- Do you have any suggestions about what kind of copper tape I should be getting? I know 3M makes a lot of different kinds of tape. Are there certain specs I should look out for? (thickness, resistance, width, etc.) I'm not sure how available that kind of thing will be in Japan, but if I can't find it at my local hardware stores I'll just import some.

By the way, Ngr, I think that information will come in handy. What I really want is to record bass at home, but I also have a strat that I may also want to record with at home, so I will have to give it the same attention. I appreciate it very much.

Just for clarification, is this definitely an RFI/EMI problem?

Jim Williams and Ngr, thanks again for taking the time to help me out.

[henryf]

I'm afraid I have more questions than answers:

1. You mentioned, "The noise does not come in and out at regular intervals." Is it coming in and going out at irregular intervals? Are there times of the day or night when it is worse? Was anything special done in the first 34 seconds of the track to keep it quiet?

2. You mentioned, "I have tried different guitars." Were any of those already shielded well? Did they use hum-bucker pickups?

3. You mentioned, "I don't experience this problem at all with any other instruments or outboard gear." Do you know if dynamic microphones pick up this noise?

4. You mentioned you have a house and an apartment. Are they in the same neighborhood? Is your tracking room far from them?

5. Were any of the amps you tried battery powered? (If you had a small battery-powered headphone amp for your bass, I'd recommend checking how the noise varies in different parts of your house.)

[ST.]

Henryf, wonderful questions! You have given me some great troubleshooting ideas.

I'll do my best to answer your questions.

1. The sound does come in and out at irregular intervals. The time of day doesn't seem to affect anything. The loudness of the noise depends on the attenuation of my tone knob. If I have the tone down all the way (like at the beginning of the track) then the noise is quiet. If I have the tone all the way open, then the noise is loud. Of course, that depends on if the noise is there at all. If the noise isn't there, then the tone knob being opened won't amplify it... unfortunately the noise ALWAYS comes back (I probably can't get it to stop for a minute).

2. None of my guitars are shielded as Jim Williams described or as described in the article posted by Ngr. None of my guitars have humbucking pickups. As far as electric guitars go, I have a strat (all single coil), the j-bass described earlier, and an old harmony rocket (which are p-90 like pickups, qualifying as single coil as far as I know). I've never messed with any of the shielding on the Harmony and don't really intend to. I can vouch for the strat and j-bass, though as I have modded them and fixed things in them myself.

3. I have never had a dynamic microphone pick up this noise. Incidentally, I have (very carefully) tested turning up the gain to 100% using an SM57 as well as an RE20 with some of the same equipment used with my electric guitars and have never even heard a hint of this noise.

4. My house and apartment are in the same city. They are probably about 5-8 miles apart. My tracking room is in a different city. I should also mention that it is in the mountains about 20 miles away.

5. I have never tried a battery powered amp at my apartment.

I'd like to make a couple of comments.

In regards to your 3rd question, I think I've remembered something worth mentioning. It is kind of out there, but I think it's related. I used to have a non-digital, non-flat screen TV from the 90's. One time, I had forgotten to turn down the volume before playing my Famicom (which is the Japanese Nintendo from the 80's). I noticed the same annoying sound coming through the TV speakers! I have since upgraded to a digital TV and haven't really noticed the sound. Maybe I can try recording the audio output of my Famicom to see if it is still picking up the same sound. Nevertheless, I'm not so sure if that can help lead to a solution.

In regards to your 5th question, I have a friend who owns a battery operated amplifier. Granted it sounds absolutely horrible, I think it will help me indicate whether or not this is a power related issue. I think it will also, as I think you're hinting at, help me figure out if the sound changes in anyway depending my position in my apartment or house.

Thank you for your great questions.

[henryf]

My current theory (Theory #1) is that your instruments are acting like an antenna for a possibly-digital broadcast in your city. When the RF signal is strong enough at the input of your amplifier, something overloads or rectifies the RF, resulting in the noise.

This would explain why things work at your tracking room -- the RF would be too weak there to cause a problem. It might explain why the tone control matters -- it might act as a RF filter. It would explain why touching the pickup causes a problem -- your body acts as an additional antenna. It would explain why you might have heard the signal through the Famicon.

A competing theory (Theory #2) that seems less likely to me than the first one, would be that instead of an outside broadcast causing the RFI, some equipment you own, such as a PC with a switch-mode power supply, is generating RFI that is somehow getting broadcast to your instruments.

Maybe some experiments with the battery-powered amp can help to eliminate theory #2, especially if you can still hear the noise when your home's electricity is shut off.

If you had access to an oscilloscope or a spectrum analyzer, you might be able to identify some RF at the input to your amp. If so, that would lend support to the "instrument as antenna" premise. If not, it might mean the RF is at a higher frequency than the scope can show.

If theory #1 is correct, adding an RFI filter might help. As a simple check, I'd try shorting one end of a guitar cable with a 3.3 pF to 10 pF capacitor, to see if it improved things. (I'd try this cable oriented both ways, cap towards the guitar, and cap towards the amp.) On second thought, this might be too simplistic, so I'd try a pi filter using two caps and an inductor, but I haven't worked out the component values for this.

In addition to an instrument with better shielding, an instrument with an active pickup might be worth a try if you can borrow one.

[Jim Williams]

The noise is entering the pickups. That's why it goes away when the tone pots are turned down. Only screening will prevent the entry of the noise, everything else is afterthought and will degrade your tone.

[ST.]

Jim Williams, henryf, ngr I just wanted to let you know that I appreciate your help and have not given up on this.

Half the stuff I was planning on ordering went out of stock by the time I got to ordering it. I should have everything by this weekend though.

I'm going to go a little off topic here...

My old soldering iron (which I threw out after I got to Japan), was terrible. I wanted to get a nice desktop one with variable wattage, but everything available was $300+ and I didn't really feel like dropping that much cash on something I don't do very often. I ended up stumbling upon a soldering iron called "hakko fx901", which is really low wattage, but supposedly very safe and convenient. I hope the fact that it's not a very normal soldering iron won't affect my ability to do the repairs ahead.

Incidentally, my DX7's battery went out sometime last week, so I will be working on my bass and my DX7 this weekend. I found some pretty good Japanese instructions on how to fix a battery holder with some leads to the DX7 so you don't have to keep soldering a new battery in directly every time one goes out.

I will hopefully document both repairs with my video camera. If I mess up, hopefully I can figure out where I went wrong... and if things go well I hope they can be used as future reference for other people with the same/similar problems.

[drtechno]

sounds like digital noise but this can be caused by electronic ballasts in fluorescent or compact fluorescent lighting, and some incandescent lighting dimmers make the same noise. I have seen this problem when the outlet ground is bad and causes the rfi snubbing circuitry to fail to work.

The way I fix this in an apartment I had was to take a wire and ground strap onto the water pipe under the sink and wire a plug on the ground lug and plug it into the extra outlet under the sink(garbage disposal outlet).

Also I have head this sound from laptop computers plugged into its charger (charger noise). Operate laptops off of battery exclusively when recording or playback.

[Jim Williams]

Originally Posted by ST.

My old soldering iron (which I threw out after I got to Japan), was terrible. I wanted to get a nice desktop one with variable wattage, but everything available was $300+ and I didn't really feel like dropping that much cash on something I don't do very often. I ended up stumbling upon a soldering iron called "hakko fx901", which is really low wattage, but supposedly very safe and convenient. I hope the fact that it's not a very normal soldering iron won't affect my ability to do the repairs ahead.

You can get a nice desktop temp controlled solder station for around $40 from:
MCM Electronics: Home and Pro Audio/Video, Security and Test Equipment

[byron123]

I had a pretty low noise environment in my studio. Then about 3 weeks ago i had a very pronounced hum/buzz on all gtrs, all amps anywhere in my house. No problems at gigs or band rehearsal though. Long story short: turned out I had repositioned the antenna on my wireless router on the 1st floor to better reach the upper floors in my house. I finally realized that was the only change that might coincide with the noise. Went to cupboard, returned antenna to vertical position and ......voila sound gone.

Went crazy trying to find buzz (bought new cables, noise gates, medication), but it was really that simple!

hope that helps someone

Byron

[ST.]

drtechno, the things you mentioned are certainly a consideration. Although in my situation my audio equipment outlet is grounded and in my home it is not... yet the same noise occurs at both locations.

Unfortunately, my apartment and house don't have a garbage disposal (which means no outlet under the sink).

Also, I use my laptop in my tracking room, where I don't have these problems. In my home/apartment I experience this noise regardless of whether I'm using a desktop, laptop, or a computer-less setup.

I appreciate your advice nevertheless. To be honest, I've never heard of "electronic ballasts" before, so I will try to learn more about them and the way they affect audio to help combat my current and/or future noise problems.

Jim Williams, the units on the website you posted are exactly what I had in mind... and for a better price than I imagined. I will be definitely be ordering one of those during my next trip to CA. Thank you for the link!

byron123, thank you for sharing your experience. Embarrassingly, I haven't had the time to try unplugging the wireless router at home (I'm usually at my apartment) so I haven't tested whether or not it will make a difference. If you don't mind, did you experience any of the high pitched noise like in the samples I posted or just hum and buzz?

I did experience a noise issue in my tracking room the last time I went. I installed a new pedal board and there was a ton of hum and buzz in the signal (no high pitched stuff like at my home/apartment though) and I spent a lot of time trying to figure out which pedal(s) was the culprit and then trying to figure out which cable was bad. It ended up being an electric rug that I had installed to try to get the room temperature at a reasonable level. The pedal board was sitting right on the rug so it was like bathing in whatever junk the rug was emitting.

Is there any way of predicting what electronics cause these kinds of problems? I have an electronic rug in my apartment during the winter that doesn't cause any hum/buzz. It feels like a crapshoot sometimes.

[ST.]

I tried a battery powered amplifier and got the same noise. That confirmed that it wasn't something coming from my power. I wish I had done that before I imported an isolation transformer!

I got 4 pieces of (15x30cm) Bartolini Copper Foil. I covered the cavities of my jazz bass with it and even did the undersides of my pickguard, the control plate, and the pickup covers for good measure. I also did the underside of my bridge which allowed me to solder the ground lead to it. I put a .022uf cap in series with that ground lead.

I don't do very precise work so I'm sure what I did was full of mistakes.

Here's what I've noticed:

- Overall, the noise that I had has really been reduced. However it's still there on extreme amp settings. If I roll the treble to about 6 or 7, it's not really very noticeable. I haven't done any tests with my DI's yet, but I'm afraid they'll pick up more noise than my amp because there's no EQ section on them.

- If I take the control plate off, then things get really noisy. It's like lifting the ground. So I get a lot of that noise on top of the RFI/EMI stuff that I was getting before. The second the control plate touches the foil that kind of sticks out of the control cavity, then things get clean. However, nothing beyond that seems to make a difference. Even lifting the ground wire from the bridge doesn't really make a difference... that's with the strings off of course.

- After working on the bass for quite some time, I decided to call it a night and started to get the bass ready to put some strings back on. After everything was set, I connected the bass to the amp one more time to see if everything was still okay (to see if anything had come loose under the control plate in particular). There was complete dead silence (with amp volume and treble at 10, which is what I have been doing my tests with... it's a little practice amp). I went ahead and made sure the pickups were still okay by tapping one of them and it was fine! Once strings were on, it went back to acceptable, but still a little noisy.

- One of the bridge pickup screws has this issue-- if I touch it with one of my bare hands, it will sound like touching a pickup pole with something metal!

- I went as far as taking copper foil and crossing from the neck pickup cavity to the bridge pickup cavity and then from there to the bridge. I haven't noticed any improvement from that. I wonder if there is a possibility of improvement or noise from doing so.

- lifting a pickup out of its foil-ed cavity increases the noise considerably, leading me to believe that the foil in the cavity is protecting against noise.

- I tested my bass for about a minute this morning and I think the noise has become louder since last night.

I have to admit, I didn't take the time to solder each piece of foil together. Is that of absolute importance with the type of foil that I got? What's a good way of checking if the underside conducts?

What kinds of trouble shooting can I do with my current set up to try to get the noise down to zero (like I experienced last night)?

Thanks again guys! Jim Williams, your advice seems to have been spot on. Ngr, your link was also useful. I have to admit though, I might buy something simpler than the current strat I have to mod for home use.

PS:byron123, I will test unplugging my router at home sometime this week or next weekend. I'll be sure to post the results.

[ST.]

I couldn't get the noise 100% out of the picture at my apartment. I decided I would take my set up to my home where I have more control over the environment.

I went to where I am planning to move my set up permanently and was delighted to hear silence. Everything was cranked to 10 and things were just fantastically quiet.

I didn't have to unplug any modems or wireless routers.

I did notice that a small fridge had been unplugged. I plugged it in, and boom! The noise was back (although very muffled compared to my pre-modified bass).

I unplugged the fridge and the noise was still there! After waiting about a minute and unplugging/plugging back in my amp the noise went away and stayed away.

I'd like to thank everyone that helped me out. I really appreciate it.