Like previous Destiny 2 seasons, Season of the Seraph is full of secret collectibles and triumphs for you to complete. Two of these Triumphs are called Music Theory I and Music Theory II, which involve searching and opening six Resonance Amp chests in Europa and Moon, respectively.
Completing various in-game activities will reward you with Resonate Stems. Combine Resonate Amp (which you get from completing the first step of the Season of the Seraph quest) with 4 Resonate Stems to find coordinates for the Resonance Amp Chests scattered around the map.
Below you will find the exact locations of the Resonance Amp in Destiny 2.
All Resonance Amp Chests locations
Europa Crossing Outpost Wall
You will find it in Charon's Crossings. Take the door opposite Variks, and you will notice a broken ledge. Drop down, and you will find the Resonance Amp Chest.
Europa Beyond Cliff Landing
You will find it not far from the Beyond landing zone. Upon landing, take the pathway on the east, and soon you will come upon the next Resonance Amp Chest.
Europa Abyss Fissure Construct
You will find it near Asterion Abyss, next to the Charon's Crossing landing zone. Traverse the giant Hex structure in the middle, and you will soon come across another chest.
Europa Ride Road Ledge
You will find it in Cadmus Ridge, near the Charon's Crossing landing zone. Keep going to the left of the Cadmus Ridge, and you will soon across some spiked fences. Keep following it, and it will lead you to another Resonance Amp Chest.
Europa Eventide Cliff Refuge
You will find it near the Eventide Ruins landing zone. Follow the cliff, and you will soon come across an opening below. Jump down, and you will notice a cave on the left. The Resonance Amp Chest is waiting for you inside.
Europa Eventide Dome Catwalk
You will find it inside the giant Dome in the Eventide Ruins landing zone. Inside the dome, look for a catwalk. The Resonance Amp Chest is on top of it.
Luna Archer Dome Catwalk
You will find it in a dome in Archer's Line, left of the Sanctuary landing zone. Once you're inside the dome, look for a catwalk. The chest is on the top of it.
Luna Hellmouth Outcropping Alcove
You will find it in a cave in Hellmouth near Sorrow's Harbor landing zone. Inside the cave, look for an opening to a room. The Resonance Amp Chest is in this room.
Luna Anchor Tower Rotunda
You will find it inside a circular building in Anchor of Light near the Sanctuary landing zone.
Luna Archer Crevasse Crash
You will find it near the crevasses in Archer's Line. Spawn in the Sanctuary, and keep heading towards the crevasses until you find a crashed ship. The chest is right next to it.
Luna Sanctuary Stage Backdrop
You will find it right behind Eris Morn in Sanctuary. Head towards the cliff, and you notice a path down. The chest is lying there.
Luna Sorrow Altar Recess
You will find it in Scarlet Keep, near the Sorrow's Harbor landing zone. Here, look for an opening in the wall next to the Altar of the Sorrow. The chest is inside that opening.
That's all about Destiny 2 Resonance Amp Locations.