KRK RP-6 constant buzz

[bakus]

I have a pair of KRK RP-6's that just wont stop buzzing. I know for sure that it isn't my audio cables because the buzz is there even when I plug in only the ac cord. Its a constant low level buzz that isnt affected by the rear volume pot, and even running them through a furman pl-II conditioner doesnt work. I'm assuming its some wiritng in my house, but even when i turn all the breakers off in my house except for in the studio, the buzz continues. It's an old house and has both dimmer switches and flourescent lights. Is there ANY way to rid these monitors of their buzz?

[kendale]

Aloha and welcome to the forum, Bakus

Any chance you could please:

Edit your profile to include your location. This is very important, because this is a worldwide resource, and as such, material costs and availability vary widely. For example, masonry is cheaper than gypsum in some parts of the globe, whereas it's the exact opposite in other regions.

This will really come in handy two or three posts down the road. It's also part of the forum guidelines: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=3231 Thanks!

Here's a couple of thoughts...

It's an old house and has both dimmer switches and flourescent lights. Is there ANY way to rid these monitors of their buzz?

- Do your monitors buzz when ALL the lights, dimmers, flourescents are turned off?
- Do your monitors buzz when plugged into another outlet in another part of the house/different circuit/at a friend's house?
- Do you have 2 or 3 prong outlets?
- I think out here (in Hawaii) you can request that the electric company (or electrician) come out and do a check to see if you're having some problems. Could it be that this service is available where you are?
- Could it be some kind of RF interference? Here's a link that might prove useful. http://johnlsayers.com/phpBB2/viewtopic.php?t=5499

Hope this helps.

Aloha

[bakus]

They buzz even when they're the only thing on in the house. I've also tried them in pretty much every outlet in the house, which are all 3 prong. The only thing I havent tried is bringing them to a friends house. If I knew for sure that the dimmers would cause the noise even when turned off at the main fuse box, I would maybe change them.

[knightfly]

Dimmers won't cause anything if they aren't powered, so that doesn't sound like it's the problem; try each speaker indepenently (only one plugged in at a time) and see if both speakers do this, or just one; if it's only one, that speaker may have a bad power supply. If both, try them at a friend's house - if the buzz goes away, it's probably your house ground system... Steve

[Don T]

Hello:
If the dimmers are on the same circuit as the power to your speakers then they are still powered. Some of these use SCR's or triacs which have fast rise times. Lots of RFI and buzz. Even if you have them "off" they might not be fully off leaving noise on the system (even if the bulbs are not lit). This may also manifest itself as buzzing amps with instruments plugged in (RFI). Taking the speakers to another location is a good idea. If they still buzz there, the probability exists there are some bad filter caps in the internal power supply. Possibly a bad rectifier. Last possibility might be dirty power. The furman should help but if the sine wave is distorted only a zero wait state UPS would provide clean power.

[bakus]

Thanks for the feedback everyone...

What exactly is a zero wait state UPS?

[serge instrumental]

Thanks for the feedback everyone...

What exactly is a zero wait state UPS?

From what you say this looks as an AC outlet, really bad AC,!

You should look with an alectric contractor(the one who made high school studies, not your next neighbor)

You should check from your electricity provider, that you're not connected to a over used (obsolete) or faulty post transformer, this could happen, because I've had some problems with TV RF interference and the Hydro-Quebec company came around(after one call) and they found that they had out of date (bad) transformers nearby my home, some twoo streets frar from my home. They had to change all of them because their transformers should "not transmitt" RF signal simply because they don't have a license to emitt those frequencies!

Don't laugh about it, my brother was working as an ingineer for this company for 30 years! So he knows about it!

A good quality signal is really important when you have audio equipement, more if you have a rec studio.

My two cents

[kendale]

Aloha bakus,

UPS - http://www.webopedia.com/TERM/U/UPS.html
Short for uninterruptible power supply, a power supply that includes a battery to maintain power in the event of a power outage. Typically, a UPS keeps a computer running for several minutes after a power outage, enabling you to save data that is in RAM and shut down the computer gracefully. Many UPSs now offer a software component that enables you to automate backup and shut down procedures in case there's a power failure while you're away from the computer.

There are two basic types of UPS systems: standby power systems (SPSs) and on-line UPS systems. An SPS monitors the power line and switches to battery power as soon as it detects a problem. The switch to battery, however, can require several milliseconds, during which time the computer is not receiving any power. Standby Power Systems are sometimes called Line-interactive UPSes.

An on-line UPS avoids these momentary power lapses by constantly providing power from its own inverter, even when the power line is functioning properly. In general, on-line UPSs are much more expensive than SPSs.

ZERO-WAIT STATE - http://www.webopedia.com/TERM/z/zero_wait_state.html
Refers to systems that have no wait states; that is, they allow the microprocessor to run at its maximum speed without waiting for slower memory chips.

http://www.nuhorizons.com/Glossary/Comp ... pts.html#Z
A condition that results when no delays are inserted into the system software to deliberately detain operation of the CPU. This can be done with high-speed memory and proper design of computer architecture. Zero-wait state is desirable for the high-speed operation of a computer.

Aloha

[knightfly]

Thanks Kendale; still, I've never heard the term "zero wait state" used to describe a UPS; in the absense of a response from Don, I'll have to "ass-u-me" he meant a line-interactive UPS, which (I guess) technically, would have a "zero wait-state"...

In my previous setup I used a 1400 VA APC ups to run most of the gear; we have high winds and frequent "bumps" and outages in winter, and I got tired of being in the middle of something and losing it - this was NOT a line interactive, and still I never lost a thing due to the slight switching delay; don't even remember any glitches in the audio... Steve

Oh, almost forgot; Don, if a dimmer has an actual "off" position, this removes power from the SCR's/Triac - so where would the noise come from without turn-on spikes?

[Don T]

Hello,
Wow, I missed this post.
If you can verify that the dimmer is actually off then it should not be putting out spikes. Easy enough to check by turning off breakers that supply them.

A "zero wait state" UPS is generating AC sine waves from DC all the time. The line only charges the DC power source. When the line power fails, there is no wait period before the unit produces AC. Cheap units have a wait period before AC is generated and it is usually a "modified" sine wave (stepping square wave). Zero wait state UPS's are not as efficient, consuming power in the conversion AC>DC>AC but produce constant, clean sine waves.

[davidicus]

i just replaced some old yamaha monitors with some KRK RP-5 ones, and suddenly i have a faint buzz out of both. i tried turning off a lot of different things, and the buzz seems to go away if i turn off my 21" Dell CRT. can't get anything done that way.

what's going on here? everything is powered through a UPS (which i thought would clean up power noise--no?). it's faint but gets really annoying, especially since i have no idea what would solve it! any suggestions?

many thanks

[xSpace]

move the speakers further away from the crt monitor.

[davidicus]

thanks--i can see where you're coming from, but two full feet of space ought to be plenty, right? there's only so much cable, and if they got much farther apart, they'd be on either side of my head. have you really seen that work?

[xSpace]

I've seen my cell phone introduce noise into headphones before it ever rings...and then it rings


If you haven't tried it...try it. If you tried it and it doesn't work, well, thats more information to move forward with right?

[bananafish]

How to tell how the CRT is interfering:

Move the speaker into another room, use an extension cord to connect it to the exact same AC outlet that it originally had in the control room. This way all your control variables are in place. If it still interferes then it's probably through the line.

If it goes away, it's probably through the air.

Solving CRT problems can be tricky. I had one interfere with guitar amps on separate AC circuits 12 feet away for years and the only way I could figure out how to fix it was to turn the CRT off until I got an LCD. Some CRTs can be very disruptive, some not. This CRT had some other quirks so maybe it was defective. I had TVs in the room which didn't do anything to the amps, just that CRT. I don't know if it is the power supply in the CRT, or the massive coils or what. Magnetic flux can carry very well. At a studio I worked at we had a CRT approximately 7 feet away from the monitors and when the volume was cranked you could see the screen distort from the speakers' fluxfields. That's not quite the same situation as this but it shows that field interference over distance is very real.

The simplest, most surefire answer I can give is go LCD if you can bank it. Otherwise do the air/wiring check above and narrow down your possibilities.