Ground Loop Isolator

This ground loop isolator eliminates engine/alternator noise caused by ground loops in your system. Also great for eliminating line-level noise in home audio and home theater systems.
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Part # 265-012

Product Details

Ground Loop Isolator
This ground loop isolator eliminates engine/alternator noise caused by ground loops in your system. Just install between the head unit and amplifier or equalizer. Also great for eliminating otherwise unsolvable line-level noise in home audio and home theater systems. Features 24 kt. gold plated connectors, one pair of RCA male to one pair of RCA female, to ensure efficient signal transfer.

Ground Loop Isolator
  • BrandParts Express
  • Part Number265-012
  • UPC086429050680
  • Product CategoryNoise Filters
  • Unit of MeasureEA
  • Product Rating
    (48 Reviews)
  • Weight0.3564 lbs.
  • California Prop 65

    Warning: California residents only. Please note per Proposition 65 that this product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.

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Ground Loop Isolator
Ground Loop Isolator is rated 4.2917 out of 5 by 48.
Rated 5 out of 5 by from I love it works just fineit stop that noise that was in my equipment from laptop I even use it my Big truck 18 wheeler so I can listen to movie throw radio without that dam noise .
Date published: 2014-01-28
Rated 5 out of 5 by from Audio Problem/ Hum SolverWhether in a car, boat, or home (even the local cable office!), hum caused by ground loops or currents in grounds between equipment components is effectively ended by this device. I am unaware of how high end audio system bandwidth and dynamic range is affected, but for the average system, the isolator is great and unnoticable.
Date published: 2013-10-17
Rated 5 out of 5 by from Used it on my Dayton SubMy sub would just start rumbling at random times, tap it with your foot and it would stop. A little research indicated a ground loop was likely, so I bought this and installed. No more problems.
Date published: 2013-03-07
Rated 5 out of 5 by from Used as a Stereo to Mono Input ConversionQuality was excellent, performance even better yet.I used this unit to parallel the inputs of a stereo amp with a mono amp. If I had just used a Y adapter there would have been a mono source feeding both channels of the stereo amp paralleled to the one channel on the mono amp. By using the Y adapter on the secondary side of the isolation transformer, I could keep the stereo alive on the primary side while using the Y adapter on the secondary side to create a combined mono source. This was a quick and inexpensive solution to a vexing problem. The mono amp speakers were in another part of the building from the stereo speakers so 180 degree phase shift was not an issue.
Date published: 2012-10-29
Rated 5 out of 5 by from Great product for the priceEasy to install & worked great! Took care of a hum that had bothered me for a long time!Great website, too!
Date published: 2012-09-05
Rated 3 out of 5 by from Works but won't cut loudest hums.Works great and doesn't seem to hurt sound quality much but will not cut the largest volume hums. Needs like 18 db more cut for my system.
Date published: 2012-05-22
Rated 5 out of 5 by from Your Ground Loop & Noise SolutionAfter the power supply for my laptop had decided it had enough, I purchased a new, yet very cheap, power supply. The only problem with these power supplies are the noise they produce in the audio stream (very common among all linear power supplies). It can sound like CPU and hard drive activity is coming out of your speakers. That's the way cheap laptop power supplies are.Of course I couldn't be the only one in the world with that problem, so I discovered a ground loop isolator would be the solution. I bought one from Parts Express.This isolator is excellent because it stopped the laptop noise from going to my amplifier when the laptop is connected to AC. It has gold RCA contacts and a good weight. As far as I can tell, there is no sound degradation using this.If your problem is hearing CPU activity from your speakers when your laptop is connected to AC, this is your solution.
Date published: 2012-04-30
Rated 5 out of 5 by from music source solutionThis is the music source solution in my system. Tired of having to hook up your computer to the stereo or park your lap top next to it when you could be using it elsewhere or docking your smart phone to it. Not anymore if you have a Bluetooth enabled device you can use it anywhere in range. (If your computer doesn’t have Bluetooth there are inexpensive Class 1 micro USB adapters, also good for extended range 100m/330ft). Parts Express Bluetooth Audio Receiver Module (BT-1), syncs easily and works cleanly. This part is meant to be built in to a system so it is a raw board with wires soldered to it which can break off easily so if you are not incorporating it into a case, it is highly recommended that you use a project box otherwise. Parts Express Project Box 3-1/4" x 2" Model: 64-8922 will do the job. The BT-1 is powered by a USB port so you might want to use a USB socket plug and possibly a USB port extension cord. Depending on your setup you may also need a stereo RCA to male 1/8” male jack, or a double 1/8” male jack. However if you’re like me you’ll have those things lying around to use. Other than the project box the only other issue that can arise is that the board because of its layout is prone to electrical noise which is easily solved by using a ground loop isolator part# 265-012, I did not encounter this issue. And other than drilling holes in the project box and mounting the board, the set up took me less than 5 minuets to do most time took me finding the parts/cords to hook it up.
Date published: 2012-03-08
Rated 5 out of 5 by from Ground Loop IsolaterI had a problem with my subwoofer humming. I was able to get some advice and purchased the Ground Loop Isolater. It did help my situation.
Date published: 2011-12-20
Rated 2 out of 5 by from Some improvementThis device did not do all I had hoped. Using on home audio system Subwoofer. Still had some low level 60Hz hum. Maybe more expensive devices would work better. Don't know. Ground loops are always a challenge.
Date published: 2011-07-20
Rated 4 out of 5 by from Tests prove that this transformer set is very goodI read some of the reviews before purchasing. One reviewer said that this item reduced high frequencies. I purchased anyway. When I received the transformer I tested it on our shop SMAART analysis system. Load was 10K ohms. Source Impedancee was 120 ohms, I was very surprised to find that the response was flat (.3db) from 20 Hz to 20Khz. Phase response was just what you would expect of a good transformer and impulse test showed nothing extrordinary. There was a .3db rise at 20Hz and 20Khz. I think that the person that said it caused a loss of high frequencies should re-evaluate his system. There's no problem with this item.
Date published: 2010-12-24
Rated 3 out of 5 by from Great Audio DUCT-TAPE !!!While this unit eliminated the hum, it also padded the highest frequencies. Works for now, but eventually I wanna take the time n trace the signal to find the problem and fix it. It's about like duct tape for your stereo.
Date published: 2010-03-06
Rated 2 out of 5 by from Eliminates Hum, Degrades Sound QualityAlthough I did find this product to eliminate the hum in my system it was at the expense of sound quality, leaving me dissatisfied. I traced the source of the hum to my cable tv coaxial cable and have implemented an isolator in line there with good results.
Date published: 2010-02-17
Rated 2 out of 5 by from It reduced my alternator whine a little.I don't think there is anything wrong this this product. It just did not work in my situation. My son (also the installer of my car audio system) thinks he might have a grounding problem. The alternator whine is not noticeable at highway speeds(low RPM when cruising) and it can not be heard when I crank up the volume. I did install 3 of these items (L&R front, L&R rear, and sub(only used L on the sub.
Date published: 2009-06-20
Rated 5 out of 5 by from MUCH BETTER THAN EXPECTEDFor price, is heavier and larger than expected. Well sealed, not bad looking if left in open area; and foremost, cleaned the audio signal in my home theater system _way_ better than hoped. Eliminated 60hz hum, but also prior ambient circuit noise. Sound quality remains great.
Date published: 2009-04-17
Rated 5 out of 5 by from This product really worksThis product definately works and really stops the humming noise in any home stereo amplifier theater systems.
Date published: 2009-04-01
Rated 4 out of 5 by from Outstanding value!I own six of these stereo-isolation transformers. A great price-concious choice for both auto and professional audio needs. Unfortunately, the input singal to output signal is 180-degrees out of phase through the transformer. For most, this will not be a problem. However, for multiple amplifier applications, the user will need to ensure to keep track of the phasing implications of using this transformer.
Date published: 2009-03-30
Rated 3 out of 5 by from Too much change in audio signalI changed my installation a little bit for a cleaner install and got the dreaded alternator noise (I should have left things they way they were - which was totally counterintuitive). I put this device between the head unit and the amplifier. It helps, but at a tremendous loss in audio quality. The gain is decreased considerably PLUS there is excessive crosstalk, totally destroying separation. In fact, vocals (which are typically center channel) almost completely drop out.
Date published: 2009-03-07
Rated 4 out of 5 by from Worked PerfectlySolved the problem of noise from my computer to my receiver. Worked perfectly. Even took out the noise generated from the reostats in the halogen lamps.
Date published: 2009-02-09
Rated 5 out of 5 by from THE $10 CUREUnbelievable performance. Had a major hum in both subwoofers due to a ground loop problem with the cable box being integrated into my home theater system This compact hideable unit eliminated not part, but ALL the hum best $10 I ever spent
Date published: 2009-02-06
Rated 5 out of 5 by from cheater plug killerThere are lots of products like this to remove humming or buzzing. This one works perfect. It removed my severe hum from my MFW-15 subwoofer. IT allowed me to use my sub without a cheater plug. Nice alternative to the cheater plug.
Date published: 2009-02-05
Rated 4 out of 5 by from Not Exactly as describedShape is more cylindrical compared to square transformer shape in closeup. Otherwise, very well made. Purpose was to reduce or eliminate the hum from my DVD player into stereo amplifier.Hum somewhat reduced but still noticeable during quiet periods. Perhaps I need to get a new receiver since mine is 20 + years old but still working. You should also match these off with a set of line level attenuators also found in this website. The -12 db, either the Harrison or Dayton brands work equally well in reducing the sound levels to normal. You will possibly get 90%reduction in hum levels more or less depending on your brand of receiver. Mine was a JVC. Otherwise, well worth the money since Radio Shack has a similar item for $22.
Date published: 2009-01-14
Rated 5 out of 5 by from Ground Hum CancelationI have used this product between a computer for a DJ and his mixer/amp. Got rid of the hum!
Date published: 2008-11-16
Rated 5 out of 5 by from good productI used it for a ground loop hum in my sub woofer. Worked perfectly and eliminated the hum.
Date published: 2008-09-02
Rated 5 out of 5 by from does what is intended - read this people!Just so you people know: what this device actually does is automatically adjust the line level voltage from your reciever and matches it to the amp. Although it is dubbed as a "ground loop isolator" it only works as such when you have multiple RCA cables (many loops in the signal wire) It will kill the sound quality and make it seem 'muffled', which usually means you need to re-adjust the gain on your amps. DONT buy it unless you are running multiple RCA cables to the rear. I recommmend hooking up your reciever to a relay for its power input, hooking up both power AND ground direct to the battery on ALL stereo equipment, using line level voltage controllers to match amp gain, and finally buy a GOOD amp for your mids and highs. Higher quality means more dB in signal to noise ratios. The higher the number the less noise. AND make sure those alternator connectors and battery connections are CLEAN BRIGHT AND TIGHT! Fight the noise!
Date published: 2008-08-17
Rated 4 out of 5 by from HmmThis product does exactly what it should do... remove ground loop interference. It seems that a few of the other reviewers cannot differentiate between ground loops and efi/rfi. This is simply a 1:1 coil with the sole intent of isolating grounds. Any efi/rfi will NOT be eliminated.
Date published: 2008-08-13
Rated 5 out of 5 by from good producthad that wine in system, installed this isolator, and no more noise, great deal for the money
Date published: 2008-06-23
Rated 5 out of 5 by from Works exactly as expencedThis product removed all traces of ground loop interferance on our 100 foot cable runs even though they are running parallel to other lines that carry low voltage.
Date published: 2008-05-12
Rated 1 out of 5 by from I wouldn't buy it again.A product of questionable quality
Date published: 2008-05-07
Rated 3 out of 5 by from Good Price, didn't work...Installed a new Amp in my car and had alternator whine/noise through the speakers. Purchased this loop isolator but the noise didn't go away after connecting between the head unit and amp. Also, RCA leads broke off when I gave the unit a slight 'tug' to make sure everything was snug. In the end, I threw this away and removed the amp and went back to using the power supplied from the head unit.
Date published: 2008-05-03
  • 2015-08-04T07:50CST
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  • loc_en_US, sid_265-012, PRD, sort_mostRecent
  • clientName_PartsExpressInternational

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Ground Loop Isolator

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Part # 265-012
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