Tripp Lite IS250 Isolation Transformer 250W Surge 120V 2 Outlet 6 feet Cord TAA GSA

Finally!After decades of research, trials, errors, marketing hype and outright advertising lies, I have found the answer to 60-cycle hum. This isolation transformer works perfectly.As a professional guitarist, I have LONG known the grief and hassle caused by bad wiring in nightclubs, studios and my homes. I have tried EVERY CONCEIVABLE method for reducing hum and noise from my equipment: shielding, "noiseless" pickups, expensive amps, mixers, power-conditioners and egregiously-overpriced cables. NONE of those things worked.Luckily, My wife is an electronic engineer. She suggested that the little "hum-x" I got from Ebtech was simply too small to do any meaningful isolation. I looked high and low, then found this Trip-Lite brand here on Amazon. The price was right so I ordered it, knowing Amazon's return policy is fair in case it didn't work.It arrived today. I plugged in it to the wall, then plugged my noisiest, cheapest guitar amp into the back of the transformer.At first, I though I must have hooked it up wrong, because there was absolutely ZERO hum. I checked the cables. Nope. Everything was right. I plugged in a guitar. Nothing. No noise. No hum.Then I turned the guitar up full. Still no noise. When I strummed a chord, it startled the daylights out of me. The guitar was up full, the amp was up full. Still ABSOLUTELY ZERO HUM.I have been searching for an answer to this pernicious ubiquitous problem for over 40 years.This thing is worth it's weight in gold to me now. I lost two expensive pieces of gear just last month: one Kurzweil keyboard and a Mackie mixer, when the poor wiring in a local nightclub fried them.This may turn out to be the best insurance policy on delicate equipment I have ever gotten. It certainly is the answer to my 60-cycle hum. The power here in my basement is the absolute worst, so it makes a fabulous proving ground ( get it? proving "ground") for this device.THANK YOU TRIP-LITE!If you have ANY sensitive electronic equipment, especially digital audio stuff, INVEST in one of these things.Unlike all the Monster cable BS, Hum-eliminators, conditioners etc.THIS THING REALLY WORKS!

I had a plasma TV that emitted a loud, intermittent buzzing noise from the rear panel that bugged me for years. I always had a hunch that the buzz was being caused by interference coming through the wall outlet, but I wasn't able to pinpoint the source. Living in an apartment complex, I don't have control over all the various electrical devices and appliances in neighboring units that could be causing interference in the wires, so troubleshooting was difficult for me.Eventually I sold the plasma and purchased a 46" LCD TV to replace it. I had an understanding that all plasmas are inherently prone to buzzing, so I thought that I'd be able to escape this problem with an LCD. But after setting up my brand new LCD and plugging it in for the first time, I was horrified to discover that it emitted the same buzz!After doing some research on isolation transformers, I decided to try this out to see if it would solve the problem. I'm happy to report that it does. The rear panel of the TV is totally silent when it's plugged into the IS250. If I switch the TV back to the wall outlet, the buzzing returns. The isolation transformer does its job.The device itself is very heavy and well-built. Everything about it screams quality. It seems that these are being made in a dark gray color now, so while the one I received doesn't match the picture on Amazon, I think it looks better anyway.Needless to say, I'm really happy I discovered this thing!Note: There's a big difference in power consumption between Plasma TVs and LCD TVs. My 42" plasma could consume up to 400 watts, so a bigger isolation transformer would have been necessary for that. My LCD consumes around 120 watts, so the IS250 can handle it.

As mentioned by other reviewers, the Tripp Lite IS-250 is not an isolation transformer. The green ground wire needs to be removed from the outlet receptacle and the existing outlet receptacle also needs to be replaced with an isolated ground outlet to isolate the case ground from the neutral. To covert it to a true isolation transformer, I mostly followed the modification procedure outlined in the review by BLine. However, I disconnected the ground wire from the outlet receptacle instead of the case screw. Note: I needed to hold the retaining nuts in place with a 6mm socket in order the remove the screws on the outlet receptacle. I was hoping to salvage the existing outlet receptacle, but ended up having to destroy it because the spring-loaded contacts simply would not release 3 of the caps/wires. The existing outlet receptacle was made of cheap brittle plastic that easily crumbled to pieces when I pried it with a screw driver to free the caps/wires. I used heat shrink tubing on the removed ground wire to prevent it from shorting exposed terminals. Otherwise, BLine’s review provides great instructions that I recommend using for this modification.A couple more comments:• I installed rubber feet to the bottom of the unit to scratching wood surfaces.• Other than the cheap outlet receptacle, overall this a very good quality product and would highly recommend it.

As others noted the grounding is not isolated. That can be easily fixed. I also modified it to make it better for my preferences I had to add a switch to the side where I have the outlets and moved the plug in cord on the back side. Now I have in front everything I need acces to! No need to move behind it to turn on. Or if facing the other way no need to reset the circuit breaker behind. No cord coming out from the front end. For my needs this is so much better this way!

I normally don't check the internal wires but some of the reviews suggest that it was not a "true" isolated transformer so the 2 back outlets were still on earth ground. When I received the item, I did open it to do a "ground pin mod" as suggested and see by yourself: It was already done! So I am 100% sure it is truly isolated now and what you should do when you receive this item is just unscrew the 5 screws on each side of the transformer, and check if the green (ground) wire is cut from the housing (where all grounds are connected)I will put some electric tape or maybe a wing connector just to make sure the wire doesn't touch the housing though. I wish it was cut further but hey it's done and it works. Thanks!

Great isolation transformer. Well priced and good quality. Used it for my theatre room where there was an unknown constant buzz, even while using a ups and a ground loop protector it wouldn’t go away. Hooked up this isolation transformer and boom any and all buzzing gone. Only downside is that it does have a bit of humming noise coming out of the unit itself so it must be stored away in a cabinet to mask that sound.

Great item...but make sure you do the "ground pin mod" (google online) if you plan to use this for repairing vintage tube equipment.

Works great - if you are using this for true isolation you will need to remove the neutral to ground connection from the transformer which is easy to do. It’s there to reduce noise, but no good if you want a circuit that is completely isolated against shorts

Like other reviews I found this product (Tripp Lite IS-250) NOT to be an isolation transformer in the electronics repair usage of the term. The ground pin AND the neutral were grounded to the case and plug.I expected that, but decided to convert it. It's an okay price for a decent transformer and case.As noted by another reviewer, they do not use an isolated ground receptacle either. No worries. You can get one: $16 at Home Depot.1. opening the case (flip it over on the foam from the box). The chassis is raised from the table top for airflow, so it rests full-time on those 10 tiny screws. Flipping it on its lid helps release the load and keeps it from wanting to drop as you take off the cover.2. disconnect the ground wire from the case screw. The ground screw was so crappy it snapped off on loosening the nut. I sanded the case around the hole and remounted the ground wire and the Faraday shield ground with a new screw.3. remove the receptacle. The nuts are fussy and don't rotate freely -- just like the ground screw. Mine didn't break, but they were a PITA. You can then easily remove the wires and caps. Just push a small flat head screwdriver in the rectangular gap behind the leads. Push towards the wires. This will release the spring-loaded contacts. Well, that's the normal way. The receptacle was so crappy that it cracked open just trying to release the wires. Point is: you don't need to cut the wires or caps from the old receptacle.4. clip and cover the end of the ground wire that branches off the neutral on the plug side of the transformer.5. install the wires and caps to the new IG receptacle. Mount it to the case. I used new screws there too. Do not ground the receptacle, i.e., the green screw on the receptacle. Snug it up, but do not connect it to ground. You might check: an IG receptacle does not connect the ground pins in the receptacle to the receptacle's own mounting chassis.6. button up and voila! - an actual isolation transformer.