Have you ever sniffed your AC ???


If so, what did it smell like ??? Hopefully, you didn't get carbon residue from sticking your nose too far into the socket and "arcing out" : )

Honestly though, i just received an AudioPrism AC Line Sniffer in the mail today. I had posted a wanted ad to either buy or "rent" one of these units. I had purchased several Audioprism Quiet Lines and wanted to see if i could find optimum points of installation for them. Another inmate contacted me and was thoughtful enough to ship his out to me on a "temporary basis". After using it a bit, i think i'll keep it ( just funnin' Ross ).

If you're not familiar with Quiet Lines or the Noise Sniffer, Quiet Lines look like little "wall warts" without any cord coming out of them. By "wall wart", i'm talking about the little black or white plug in transformers that come with cell phone chargers, video games, cordless phones, etc... These contain what are called a "parallel line filter". In English, it is simply a tuned circuit that is designed to trap and filter AC line noise. You simply plug them in and they work ( supposedly ).

The Noise Sniffer is a box with a front mounted speaker, a volume control and a two pronged power cord. Needless to say, it's not too tough to work. You plug it in, adjust the volume and listen. Hopefully, you won't hear much at all. If you do, that simply means that your AC line is "dirty" and has noise on it. The more noise that you hear, the more severe the problem. This noise can be coming from the outside lines or from something that is pumping noise back into the line right in your own residence. As such, you can somewhat narrow down exactly what is creating "hash" within your AC system by doing some simple detective work.

By plugging the Noise Sniffer into various outlets around the joint, you can see which outlets ( or devices ) are generating the most noise. Obviously, the usual suspects will be the fridge, computer, etc... You might be surprised what you can hear and track down with this little device though.

I first plugged in the Noise Sniffer at work ( that's where i had it shipped to ). I am in a large commercial building with TONS of electrical devices running all over the place. MAN, was there a nasty, hashy buzz coming out of the speaker. Talk about annoying. This happened in every outlet i tried. I assumed that i would get this, as i had run into major problems with noise and interference coming into my test equipment before. I had also assumed that a large commercial building like this would be a LOT noisier than my personal residence. BOY, was i WRONG.....

Once i made it home, i plugged the Audio Sniffer into an outlet in the HT room. BZZZZZZ, CRACKLE, POP, POP, POP, etc... Wow. Just as nasty and possibly even worse than at the shop :( Besides the continual nasty hash and grit, the "popping" was on a time schedule. It appeared to be coming through about once every second. I proceeded to check several other outlets, all with the same results. I began to wonder "is there ANY place with clean AC" and "what the hell is giving me that damn POP" ??? After doing further testing, i don't think there is such a thing as "clean AC".

In the instruction booklet, it talks about testing various outlets, finding the noisiest ones and installing a Quiet Line filter in those spots. Well, if that is the case, i would need a filter for EVERY outlet in the house. Not ONE was any better than the other, they were ALL terrible !!!

Out of curiosity, i tried plugging the Sniffer into one of the outlets in my Monster HTS-2500 PLC in my computer room system. I was overjoyed. SILENCE !!!! I proceeded to crank up the gain and put my ear very near the speaker. Ever so faintly, i could barely hear the "pop, pop, pop" of whatever it was. Well, the "lowly" Monster had gotten rid of 98% of all the noise. I decided to try some of the other unused outlets on the HTS-2500. Since i'm not using the outlet labled "Amplifier", i plugged the cord in there. Now i could hear a very plain "POP, POP, POP". However, all of the other hashy, crackly grit was gone. Evidently, the amplifier section on this filter doesn't have quite as much filtering. One might expect this though given the power demands of an amp and the increased cost of filtering at higher current levels.

Having found this out, i ran over to the living room with the HT system in it. I wanted to do a comparison between the units. I plugged the Sniffer into the HTS-2000 PLC that i am using there. All of the outlets gave the same initial response as the HTS-2500 did. Dead quiet with an extremely quiet "pop, pop, pop" way down in the bottom of the speaker. Plugging it into the "amplifier" outlet on the HTS-2000 gave me the same results as the 2500 again. "POP, POP, POP" but with no hashy grit. Okay, these "power line conditioners" and "filters" REALLY do work.

By this point in time, i had played around / done enough investigating and wanted to find the source of that damn "pop". I plugged the Sniffer into an outlet, cranked up the gain and started pulling plugs out of the wall room by room. I assumed that it was something connected to a timer or a clock, as it seemed to occur every second or so. I think that i narrowed it down to one of the clocks in the master bedroom. With two alarm clocks and a VCR in there, i was sure that i had found the culprit. Since my girlfriend was trying to go to sleep, i was greeted with .... well, you get the idea. I'll have to try tracking it down further sometime tomorrow.

As to seeing what the Quiet Lines did, i plugged the Noise Sniffer into the bottom outlet of a dual wall socket. This outlet is on the same circuit as my system in the computer room. I cranked up the gain and heard nothing but hashy grit and popping. I took a Quiet Line, plugged it into the outlet above it aaaaand..... silence. All of the hashy grit was gone. The "popping" was still there, but it was DRASTICALLY subdued. Needless to say, i was SOLD and SOLD BIGTIME on these little "wall wart filters". The fact that you could plug them in ANYWHERE and "suck up" noise makes them as versatile as you could possibly ever hope for.

I proceeded to install a Quiet Line into an unused outlet on each of the PLC's in each of my systems. I figured that putting it as close to the source of where the components are getting their power is as good as it gets. This should filter some of the junk that "sneaks by" the PLC itself AND "snag" any garbage that is being pumped back into the line from some of the noisier ( i.e. "digital" ) components. Kind of a "two fer one" type of deal if you ask me.

I'll have to hunt down the source of my "pop, pop, popping" sometime later this week. Hopefully, some ferrite on the power cord at the source will take care of that situation. I'll also be looking for other good places to install the rest of my Quiet Lines.

I'll keep you folks posted as to what i find. Knowing what makes noise, how to treat it at the source, etc... is always good to know. In the meantime, I can't begin to recommend the Audioprism products enough. I've already noticed a reduction in treble smear and seem to have a blacker background. As to those that doubted the benefits of AC line filtering, hearing is believing. Or should i say "NOT hearing is believing" ??? Sean
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sean
I would like to thank Sean for his detailed post. I also use the Audioprism Sniffer and the wallwarts. They are excellent. I have also used an expensive Oscilloscope to verify that the Sniffer was both catching all the noise and not firing on a clean circuit. The sniffer is accurate. One additional use is to see how much junk many very expensive digital transports, DACs etc. put BACK out on the line. Put a multiway plug into a clean AC source. Plug in the sniffer and then plug in the digital device. Here is a cause for filtered power cords.
When I got my Sniffer, I discovered horrible noises above and beyond the typical "buzz", coming from where the computer was plugged in (ouch, has to be on same circuit as the stereo). Turns out it was due to daisy chaining (I know, I know) 2 power strips. Screwed a six way splitter over the wall outlet, un-daisy chained the strips, and noise was gone (at least after the UPS is charged up).

Next, got a somewhat random popping noise before and after an Adcom ACE-515. Turns out I had the TV plugged into one of the low level outlets. Moved it to an amp outlet, and popping noise was gone. In both cases, I believe that the MOVs were firing due to inappropriate loads.

Now for the big news: if you think that "digital" components necessarily make more noise than "analog" components, play around with a Sniffer. I'm using PS Audio Ultimate Outlets on the output of a P600 to keep the noisy gear from polluting each other. The Sniffer takes the guess work out of getting that last bit of performance.

Mike
Sean,
My entire system is plugged into 3 dedicated circuits. Do you feel they would be of value there? I would need only three; the number of cirscuits.

Albertporter,
If I plugged the warts into my dedicated lines, would they cause my "wireless" dimmer switches to not work?

Richard

For clarity sakes, when I mentioned Daisy chaining HTS´s the idea is not to overload the outlet but by judicious use of them enhance the filtering for low power consumption components.
Regards