K KRIËGER 1150 Watt Voltage Transformer, 110/120V to 220/240V Step Up Step Down Converter with AC Outlets, MET Approved Under UL, CSA

I highly recommend this product and its manufacturer. I bought the ULT850 (850W) to use up to 650W at 220Vrms 50Hz. I chose it because (1) it has a toroidal core, (2) it is very well assembled inside, (3) it is from the USA and (4) its design is compact and simple.I received it quickly, and in the box I found exactly what was advertised. I tested it with no load and with a moderate load (with oscilloscope). It is quiet and delivers the pure sine wave voltage it should deliver.Some buyers complain because it does not transform the FREQUENCY. It is true, but no transformer does that !!! To buy this type of product you have to have the minimum knowledge. If not, you have to ask someone else to make the purchase.Other buyers complain because it is EXPENSIVE . . . THAT IS NOT TRUE ! Just look at other similar ones. In particular, it is important to consider the quality of the materials and the way it is assembled. This product has an excellent quality-price ratio.Finally, there are those who say that it is NOISY. It's hard to believe that, because the magnetic field leaked by a toroidal core is minimal. To make it noisy, it would have to have a fracture in the ferrite core. That could happen after a heavy hit, but the casing would also have to be damaged. Therefore, if the transformer is noisy, surely the core is fragmented and so you should contact the manufacturer, Kriëger, who have EXCELLENT CUSTOMER SERVICE.

Update after SEVEN years (2016 - 2023): Still works absolutely flawless. Not a single hick-up. About a year back I put it under heavy stress in a remodel project with a German Bosch hammer drill to remove tiles in a dusty environment. No issues whatsoever. We don’t ever unplug it or shut it off. Still driving our Europan coffee maker and grinder. 1000% recommended brand and quality.I am using this transformer in the United States to power a Italian Rancilio coffee maker and a Askaso grinding mill. It has enough power to deal with both of those at the same time. The coffee sucks a maxmium of 1100 watts of power and the grinder 200 watts. It also works perfectly fine with a german mixer I own.This thing is perfect for people who live in the United States or other countries which have 110V/60Hz or even the other way around if they want to move to a European country with 230V/50Hz. The transformer works both ways. Just make sure that you have the right input voltage selcted on the backside.Conclusion: I have this transformer in daily use since a year. Sometimes its powered up the whole day. I switch it on and off with a switchable wall plug. If you do it this way make sure there is no load switched on it would cause peak currents otherwise which can damage the transformer, the switchable plug or the attached devices. The design of the transformer is very sturdy. It feels nice and well fabricated. It is also super heavy. It feels good that way. No smell or noise coming out of it. I also tried it with a European hair dryer, 900 watts. Worked perfectly as well.100% recommendation.

Used for about a month. No issues and it looks to be well built.

We have 5 of the 7 wattages (and a half dozen or more of the 150 watt unit) that are offered of the Krieger Transformer, from 150 watts to 1700 watts. We're currently in year 4 of a 7 year deployment in Belgium, and I don't mind telling you we miss our US appliances more than anything else. Okay, Costco, Sprouts and Home Depot rank high up there on the miss list too, but this is all about living in Europe and having some US electrical device that outperform their European counterparts by a wide margin. The Belgian people are wonderful, but living in Europe is a tough transition if you're doing anything more than working and sleeping.For our rather sizable collection of non dual voltage electrial devices that we simply didn't want to repurchase over here or leave behind, we use Krieger Transformers. This includes vacuum cleaners, printers, televisions, receivers, fans, you name it. Some we have eventually had to replace and there were 220v viable options, but some things, like fans, we gotta stick to the US offerings.Sure, our Air King fan motors probably don't like the 50/60Hz switcheroo, but they're doing fine so far and oh my, do we use them, because European fans can barely move a feather at full speed. You can see where this might be a problem since Belgium can hit some seriouly high summer temps and yet the entire country seems to hate central A/C with a passion. So you're stuck with portable A/C units in the house that aren't exactly stellar performers when it hits triple digit F temps, and fans every other time it's too warm to handle with just the windows open. Thank you Krieger Tranformers, for all you do for my Air King floor fans!Speaking of windows, did you also know Europe doesn't seem to like SCREENS on windows? And it's mosquito central over here! I've ended up making my own screen inserts for our house windows to fight back against the demonic mosquito contagion, thanks to my compound miter saw and...you guessed it...a 1700 watt Krieger Tranformer. Oh, and the necessary parts to make the window screens courtesy of Amazon US and their APO shipping friendly policy.So trust me, these Krieger Transformers are the real deal, can handle 24/7 usage without overheating and keep things humming along for as long as you need them. Highly recommended.

[Edit - rewritten after I used it for a few months]Used it, works fine, powered several old Russian analog audio effects devices and a vintage Roland guitar synthesizer with euro 220 volt power supplies off of it (with a euro style power strip I bought off Amazon of course) It is very well constructed, better than any other step up down transformer I’ve owned before. And it is UL listed (Or at least said so in the listing on Amazon) which is also unlike most others I’ve seen, and it was relatively inexpensive which are why I bought this model.

This transformer is well engineered and thoughtfully built. Quality throughout, they cut no corners. One thing I missed in the description was that it comes complete with all necessary cords (and 2 extra fuses). I bought a European style cord to be sre I could connect and didn't need to.