How can I use amplifiers?

[BlazingTiger]

I'm finding these amplifiers and I'm thinking wow, now what?...

[RavenTW]

You have to combine them with Guards. Assist Guard(Shifta/Deband), Red Guard(Foie series), Yellow(Zonde series), Blue(Barta series), and Recovery(Healing techs). The new shield will enhance the technique that was the name of the amp (if you find an amp with a color for a name, it increases a whole series of techniques).

[BlazingTiger]

Do I have to take these guards and amplifiers to anyone to combine them, or do I do this on my own?

[Al-Rappy]

You do it on your own. Just have an Amp and the Barrier of the same type in your inventory at the same time then clik on the Amp and hit Use.