Pinkal amps

Amp of Darkness
Location: 1P mode Mines1 (Hard), no quest.
1. Enter first room and destroy 6 boxes to your left.
2. Go to other end of room for another 3 boxes, disposing of 8 Gilchic along the way.
3. Walk out, repeat.

SI Barrier
Location: 1P mode Mines1 (Ultimate), no quest.
1. Enter first room and destroy 6 boxes to your left.
2. Go to other end of room for another 3 boxes, disposing of 8 Gilchich along the way.
3. Walk out, repeat.

RA Barrier
Location: 1P mode Mines1 (VHard), no quest.
1. Enter first room and destroy 6 boxes to your left.
2. Go to other end of room for another 3 boxes, disposing of 8 Gilchic along the way.
3. Walk out, repeat.

Amp of Si
Location: Ruins1 (Normal), Endless Nightmare4.
1. First room, eliminate 8 Claws. Head east to a room with 6 boxes.
2. Head west to next room containing 3 groups of Claws and another 4 boxes.
3. Continue to a large box room blocked by multicolor gates. Check the contents of the 4 blue boxes. Don't bother unlocking the blue gate to get to their contents unless you see a red object of interest.
4. In the crater/waterfall room, head directly behind the waterfall to pop another 4 boxes.
5. Repeat.

Amp of Gi -and- GI Barrier
Location: 1P mode Seaside (Normal), no quest.
1. Go to seaside and destroy the first 4 boxes at the entrance.
2. Go across the sand to another 4 boxes, avoiding some traps along the way.
3. Repeat.

Amp of Ra
Location: 1P mode Ruins 2 (Normal), From the Depths
1. Enter R2, sit though a brief cutscene.
2. Head right, open the "box" (which I think can drop anything including amps), and press two switches.
3. Head to the opposite side, press the two other switches to gain access to 5 boxes.
4. Backtrack and head left from here for another 4 boxes while ignoring some Claws.
5. Repeat.

Assist Barrier

Light Barrier

Amp of Megi

Amp of Segai

Amp of Healing