The 9 Best Isolation Transformers

Editor's Notes

February 08, 2021:

It was a fairly straightforward round of updates – as we determined that our existing rankings, in their entirety, were still worth our users’ consideration – but we did find manage to dig up a couple additional options that we thought were worth including.

Our first new pick, the Jameco Valuepro GRP-1200, is a basic model that we selected based primarily on its budget-friendly price. In addition to offering two isolated outlets for your protected equipment, it also has a pair of standard, 120-volt outlets that you can use for less-sensitive gear, as long as you’re ok with hooking up to the same circuit as your protected loads.

Our second new addition, the Umi AV250, caught our eye with its contemporary aesthetic, which will likely make it a shoo-in for users who’re sensitive about the styling in their recording studio. Just note that, despite its two-outlet configuration, this model’s maximum power rating tops out at 250 watts, which significantly limits the equipment you can connect to it.

September 06, 2019:

When seeking out an isolation transformer, its intended use is paramount. Hobbyists are going to have much simpler needs than experts in medical fields or engineers in a recording studio. Interestingly, the vast majority of isolation transformers currently on the market don't offer true circuit isolation, in that so many have three-prong outlets whose grounds — if you trace the circuit back to the building's breaker or the telephone pole outside — actually connect to the neutral line. This can create a potentially hazardous situation for the unsuspecting hobbyist, as he or she could easily hook up a grounding clip to an otherwise safe component and either experience the unpleasant effects of an electrical shock or cause significant damage to their equipment.

One of the reasons that there are so many Tripp Lite models on our list is that they're relatively easy to tinker with, so savvy customers can actually remove this grounding with relative ease to create true isolation for their workbenches. A simple shortcut to this would be to employ a three-to-two prong adapter, which is included with one or two of the offerings listed. Of course, this kind of thing is only really necessary if you're after that highest degree of isolation. Most users are happy with the noise and surge suppression that many of these models offer, whether it's for use in medical fields, musical spaces, or something else. And we took that general use into account when selecting things like the Tripp Lite model at number three, which offers an admittedly short period of battery backup, but that gives you enough to make sure you can save valuable projects and even back them up onto external hard drives before the power goes completely out or a generator can kick on.