GenzBenz Streamliner Pt 8...

[N. Kentucky Bass]

This is a low-tech idea, but sometimes the rafters and joists in my house buzz when I play the Streamliner 900 even at low volume. It can sound as if the buzz is coming from the cab so your experience may be deceptive. Try playing the rig somewhere else to see if the buzzing disappears.

 

[boethius]

The symptoms you describe indicate that the problem may not be with your amp but with the bass pickups or preamp (if active). Have you changed the battery (if active) or tried with a new cable & bass? Is it possible that your bass is picking up noise from lighting or some noisy electrical device?

If turning the treble down on the bass reduced the noise, this indicates that the noise in entering before the bass's eq, and if touching the strings reduces the noise, it may also be that the bonding wire between the input jack's ground and the bridge is either loose or broken.

I agree. Yes I changed the batteries...first thing I did...as they are both active, the one with Bartolinis the other with the Warwick MEC. And I think I would be leaning towards the basses if they had not been whisper quiet when I first plugged it in. The buzz started after the third time I powered it on...and all I have down with it is take it out of the box and put it on top of the cab in my office...no gigs.

On my way to try both at a local shop. We'll see what that reveals.

Thanks for everyone's input! Very helpful!!

 

[boethius]

...and in the end, it's my house. Brought STM 900 to local shop...no noise at all...no noise from my bass, shop basses, etc. and vice versa. The Warwick was whisper quiet in their floor amps. The guy in the shop thought it could be do to all of the dimmers in the house...almost every room has at least 1 dimmer switch!
Problem solved...now I just need to get a Furman. Thanks again for everyone's input!!

 

[agedhorse]

Before assuming that you need a power conditioner (which may not help one bit), verify that the power source you are connecting to is properly wired and grounded. The earth ground will help control noise migration through the power system and your bass strings are connecxted throughthe bridge, through the input ground of the amp all the way back to the main earth ground of the electrical system. If your system makes noise that changes when you touch the strings, that's an indicator that your ground is not solidly referenced. Identify the problem and fix it rather than hoping a power conditioner will mask it.

 

[sunbeast]

I always though that a buzz that went away when you touched the strings meant there was a problem with a ground connection at some point in the chain also, but then I was corrected and told that is actually what SHOULD happen- the strings are actually grounding your body through the bridge/amp/wall when you are touching the strings, as your body acts like a big antenna for electrical signals that can cause noise (for instance if I type on my computer while my bass is plugged in on my lap I get a whole bunch of buzzing that goes away if I either touch my strings or move away from my computer- my body is transferring electrical signals from my computer through the pickups unless I ground myself on the strings).

Active pickups like EMGs are internally shielded so well that you don't even need a ground wire to the bridge on those instruments as they don't pick up the signal from your body- I'm kinda surprised that the active systems in your basses are not designed in a similar fashion.

 

[Red Planet]

Get an outlet tester at Home Depot or the like. This will tell you of polarity and ground etc... now this is not the best way to really check your ground but it should suffice. A Megger is the best way I know of to test for a true ground.

Another way to test is with a digital meter. If you read from ground to neutral you should get 0 volts. Not fluctuations mind you but dead on zero volts.


If you indeed have a ground and your outlets polarity is correct then I'd start thinking about the dimmers. Dimmers do cause RFI/EFI.

 

[agedhorse]

I always though that a buzz that went away when you touched the strings meant there was a problem with a ground connection at some point in the chain also, but then I was corrected and told that is actually what SHOULD happen- the strings are actually grounding your body through the bridge/amp/wall when you are touching the strings, as your body acts like a big antenna for electrical signals that can cause noise (for instance if I type on my computer while my bass is plugged in on my lap I get a whole bunch of buzzing that goes away if I either touch my strings or move away from my computer- my body is transferring electrical signals from my computer through the pickups unless I ground myself on the strings)..

Not necessicaily true. You may also be dealing with a VHF which can have similar symptoms but a different cause. Ground id not really ground at high frequencies due to capacitance and inductance.

The symptom the OP describes is most commonly a loose ground wire inside the bass, or a poor ground on the AC power side skewing any possible earth reference and making the bass more likely to pick up environmental noise of all kinds.

If the bass checks out good, then the next place to look is the AC power system grounding. Added bonus of fixing the AC power in increased safety

 

[KJung]

Not necessicaily true. You may also be dealing with a VHF which can have similar symptoms but a different cause. Ground id not really ground at high frequencies due to capacitance and inductance.

The symptom the OP describes is most commonly a loose ground wire inside the bass, or a poor ground on the AC power side skewing any possible earth reference and making the bass more likely to pick up environmental noise of all kinds.

If the bass checks out good, then the next place to look is the AC power system grounding. Added bonus of fixing the AC power in increased safety

+1 I had one outlet in my previous home that resulted in this issue. First step is try a different outlet that is on a different circuit breaker, or preferably one in a totally different location.

 

[boethius]

+1 I had one outlet in my previous home that resulted in this issue. First step is try a different outlet that is on a different circuit breaker, or preferably one in a totally different location.

This is a rental, so I don't have the liberty to make changes to the wiring system. I have tried different outlets on different circuits....however the builder loved these dimmer switches with an on/off push button under the slide and put at lease one in each room. I'm not sure how to differentiate between the VHF/EMF type interference and what is an improper earth ground...or how to circumvent either without bringing in an electrician. Is there anything I can do to test and verify? Is there a low tech or cheap way to circumvent either?

 

[agedhorse]

First thing is to verify that you have a ground present. That would be by using a simple outlet tester. Note that it won't show all faults but is a good start.

Are the dimmers dimming compact flourescent lamps by chance? If the dimmers AND lamps are not rated for this, bad noise can result in addition to being a potential source for fire.

 

[boethius]

First thing is to verify that you have a ground present. That would be by using a simple outlet tester. Note that it won't show all faults but is a good start.

Are the dimmers dimming compact flourescent lamps by chance? If the dimmers AND lamps are not rated for this, bad noise can result in addition to being a potential source for fire.

No, no fluorescent lights. I'll check the outlets for ground and start there. Right now I'm just hoping it's bad noise... And not a fire hazard as well!! Thanks!

 

[agedhorse]

No, no fluorescent lights. I'll check the outlets for ground and start there. Right now I'm just hoping it's bad noise... And not a fire hazard as well!! Thanks!

I'm talking about the compact florescents not the long tubes. Spiral or twist type... and they make them in floods where it's difficult to tell. I've seen a couple of problems like this which is why it's a likely possibility.

 

[boethius]

I'm talking about the compact florescents not the long tubes. Spiral or twist type... and they make them in floods where it's difficult to tell. I've seen a couple of problems like this which is why it's a likely possibility.

Ground tested fine in all outlets...in whole house. No compact fluorescent bulbs either. The spots in the family room were a bit of a challenge...13 ft ceilings...but old fashioned incandescent bulbs. So no worries there. I think the only thing really left is the dimmer switches. Which I am stuck with.

Will a power conditioner clean it adequately? I have used Furmans in racks, but mostly to put amps, preamps and effects all on the same power source. I'd prefer not to spend the $ if there is a cheaper way...but if that will work, great. Thanks again for all of the advice. I really appreciate it!

 

[LarryR]

If had similar problems. Consider taking the rig somewhere else and see how it sounds. Re: grounding issues with electrical, I'm told it's easy to fix. An electrician could do it, maybe yourself via google search. IF that's the problem of course.

 

[steve_rolfeca]

...Will a power conditioner clean it adequately? I have used Furmans in racks, but mostly to put amps, preamps and effects all on the same power source...

I used to work with conditioned AC oower in industrial telecommunications installations, and grounding problems can be a real pain.

In my experience, I've never seen an affordable rack conditioner that could overcome this type of problem. Giving you some surge protection is about all a Furman is good for.

What did you use for a tester?

 

[agedhorse]

In my experience, I've never seen an affordable rack conditioner that could overcome this type of problem. Giving you some surge protection is about all a Furman is good for.

What did you use for a tester?

Yes Steve, that's pretty much my experience as well.

Is there noise with the dimmer switches turned all the way off?

My hunch is that radiated noise from dimmers and wiring (that's not in steel conduit) is being picked up by the bass electronics or pickups.

Does the noise change with the position of the bass? Have you double-checked that you have a shielded insrument cable and somebody didn't swap with a speaker cable?

 

[boethius]

I used to work with conditioned AC oower in industrial telecommunications installations, and grounding problems can be a real pain.

In my experience, I've never seen an affordable rack conditioner that could overcome this type of problem. Giving you some surge protection is about all a Furman is good for.

What did you use for a tester?

I used just the cheap little socket tester made by ideal....no I don't have a nice fluke to test it properly or to test at the panel. All of the sockets in the house that I tested were good. I wonder how much it has to do with the way the builder integrated these fader switches and a house vac system. Although it still buzzes in whatever socket I have it plugged in with the circuit off for the central vac. This is just driving me nuts and not sure where to go from here other than an electrician...but again this is a rental.

 

[boethius]

Yes Steve, that's pretty much my experience as well.

Is there noise with the dimmer switches turned all the way off?

My hunch is that radiated noise from dimmers and wiring (that's not in steel conduit) is being picked up by the bass electronics or pickups.

Does the noise change with the position of the bass? Have you double-checked that you have a shielded insrument cable and somebody didn't swap with a speaker cable?

Noise doesn't necessarily change with the position of the bass. Yes, I use monster cables, the bass ones and have neutriks going to the cab.

That's the thing...I took it into a shop, bass and amp separately or together are whisper quiet with the same cables, with their cables as well. I haven't tried with dimmers all the way off...I usually test at night when kids are in bed and I'm home from work. I do leave them all the way up when on. I can try that. I'd stand on my head and cluck like a chicken if it would help at this point!!

 

[agedhorse]

I just though of a couple of other possible sources of interference that have cropped up...

1. I-Phone or Blackberry sitting on top of the amp or close to your bass/cable

2. Computer or monitor close to your amp/bass/cable

Both of these CAN cause the same symptoms by contaminating the sensitive ground paths with high level RF. Ground is not really ground at RF frequencies, which is partially why.

 

[reasonbass]

My 600 finally came in! I am very happy with it.

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