Normally dynamic and ribbon mics should not get any Phantom power because they may get damaged. Instead you need to boost their gain on the mixer quite a bit, and with some lower quality internal preamps this may raise the noise level as well.
The FetAmp solves this by sitting between the mic and the mixer/amp, taking the Phantom power and using it to cleanly amplify the mic signal. It also blocks the Phantom power from going into the mic so it protects the mic from accidental power.
Simple, useful, works straight out of the box and hardly needs instructions. The Thomann FetAmp is an equivalent product to the TritonAudio FetHead, but at a lower price. It is slightly longer than the FetHead if size matters.
Pros:
* Clean amplification
* Protects dynamic / ribbon mics from accidental power
Cons:
* An additional dongle that you need to place somewhere along the cabling, or directly on the mic. You'll need to find a place for it.