S.O.S.--need help diagnosing/correcting noise
Oct 30, 2008 at 8:10 PM Thread Starter Post #1 of 12

ComfyCan

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I have a noise in my system that is driving me nuts. It only occurs when I use my turntable, never when playing cd's. It is only in the right channel, and it sounds like "Dat-did-did-did-did," in rapid-fire. It happens every few minutes, and only lasts for 2-4 seconds. The sound is quite similar to the sound they play in old movies or cartoons when someone is operating a "telegraph." It may be a ground loop; I've never had one and don't really know the symptoms, but I always thought it was more of a steady hum? My noise is not at all steady, it is intermittant (and quite pesky). I'm reasonably sure it's not the speaker, because it also comes through the right channel of the headphones.

Here's the analog system: Technics 1200>Yaquin MS 12-B phonostage>Grace M902 headphone amp/preamp> Kingrex T-20 amp w/Kingrex dedicated PSU> Wharfedale Diamond 9.1's. All RCA interconnects are Blue Jean Cables' LC-1's. The speakers are wired with Canare 14-guage star quad wire. There is a ground wire running from the grounding post on the KAB-modded Technics to the grounding post on the Yaqin phonostage. All components are plugged into a Monster Power Pro 2500 power conditioner. I do not have any other dedicated ground wires in this system, although there is an available grounding post on the power conditioner.

My Digital setup also runs through the Grace, but does not pass through the Yaquin. I have no feedback noise when using digital media.

Any ideas? It seems logical that the Yaqin tube phonstage may be at fault; should I perhaps try running ground wires to all components in the chain? At the moment, all of these components are packed pretty close to one another, and there is also a giant computer monitor in close proximity. I do plan to move the speakers farther away after I buy or make speaker stands, but at the moment the right channel speaker is quite close to a bunch of components. I have no idea if that matters or not.
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Thanks for any help/suggestions. This system is dead-quiet and sounds wonderful until this noise thing disrupts it.
 
Oct 30, 2008 at 11:10 PM Post #3 of 12

ComfyCan

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Checking now (never would have thought of that).

Update to follow; thanks.
 
Oct 30, 2008 at 11:21 PM Post #4 of 12

ComfyCan

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I may be jumping the gun here, but I think the problem was that one of the phonstage tubes was just not seated properly. I switched them, as Jade suggested and the problem didn't move--it disappeared, which is of course ideal
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.

Thanks much! I was hoping it was just a "little thing" like that. This is my first tube device (other than a guitar amp) and I just don't know the ropes.

I'll be back if it starts again, but it's been 15 minutes and no more staccato noise, so I'm pretty sure we can put this thread to bed.

Whoop!
 
Oct 31, 2008 at 1:55 PM Post #5 of 12

Orcin

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If it starts again, try removing your cell phone from the area.
 
Nov 4, 2008 at 11:31 PM Post #6 of 12

ComfyCan

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Quote:

Originally Posted by Orcin /img/forum/go_quote.gif
If it starts again, try removing your cell phone from the area.



This turned out to be a huge factor as well. The problem improved quite a bit when I reset the tubes, but there's no doubt that my pesky Blackberry is the primary cause. When I stash it out of the way, no noise.

Thanks again.
 
Nov 5, 2008 at 1:15 AM Post #7 of 12

Bones13

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My iPhone really messes up in my office, both the VoIP phone and my audio rig. I end up having to leave it on a chair in the other corner of the room. Exactly the sound you were describing.
 
Nov 5, 2008 at 1:49 AM Post #8 of 12

Uncle Erik

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That's the sound of your cell phone "checking in" with a cell tower. Cell phones do that periodically.

What you're hearing is RFI, because a cell phone is really a radio transmitter. Your gear and cables pick up the radio waves like an antenna then feed that into your music.

You can, of course, turn off the cell while you're listening. Keeping it away from the gear also helps, and so can using shielded cables. But RFI can be a tricky beast to pin down. Radio waves scatter, reflect and can get in through the smallest places.
 
Nov 5, 2008 at 3:50 AM Post #9 of 12

Golden Monkey

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Ferrite cores will help a little bit a well...
 
Nov 5, 2008 at 5:08 PM Post #10 of 12

moogoob

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I was about to say "cell phone"
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In particular, GSM phones are the worst for this. My system will even pick up the Wifi transmissions from my laptop, precipitating me buying a longer USB cable to get it farther away.
smily_headphones1.gif
 
Nov 5, 2008 at 9:30 PM Post #11 of 12

ComfyCan

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What I'd like to do is throw the pesky thing (Blackberry/cell phone)into the river. Probably not a good career move though.
ph34r.gif


Remember how these things were supposed to make life easier?
 
Nov 6, 2008 at 12:04 AM Post #12 of 12

Golden Monkey

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Absolutely HATEHATEHATE mine...Friggin' IT job...
 

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