I use this unit to provide phantom power to a high end Crown headset mic. I chose it primarily because Rolls has a reputation for building tough equipment and it's also one of the smallest (ergo most portable) and least expensive stand-alone phantom power units on the market (choices here are limited, given most mid and upper end PA boards already provide phantom support).

In use, it's been reliable and whisper quiet, even at the 48v setting (it can be set to either 12 or 48 volts). It consequently allows the condensor unit of the headset to provide an extremely clean and clear output. Our sound man says the gain on my line blows away that of the Shure 58's the other band members are using.

Yes, an on/off switch would be a nice addition, but for my application that would be somewhat superfluous (the belt pack for my Crown aleady has an on/off switch, so I can avoid "pops" by keeping it off when plugging or unplugging it from the Rolls). And adding a power switch to the Rolls would likely ad more potential noise to the circuit (as well as additional cost).

Note that the Rolls uses an external "wall wart" power supply (supplying 14-18v DC). While that may seem to be an annoyance (something else to misplace/lose), it's actually a slick little design approach - keeping the step-down transformer circuit away from the audio line helps keep the unit quiet. That approach is actually used in some very high end audiophile line preamps for precisely that reason.

This adapter has provided phantom power for the single condenser mic our bluegrass band uses. 50+ shows per year for the last 6-7 years. It always works, and I've never had a backup because I trust it will always be ready to go.

Cheaply made, overall, in every way. It does do, what it says it'll do... but for how long, I'll find out I guess. Not thrilled with this purchase; would have been less diturbed at about half what I paid, maybe. If you don't need a phantom power stand alone unit, use what you've got already, in my opinion.

No features to it really, but in home studio use for single input mics, it's dependable, no noise and gets the job done. really needs an on/off switch, but that would be another circuit that could add noise.