While Wuthering Waves has a Pokedex-like library of Echoes, these battle companions are difficult to level up because their level-up materials are relatively hard to come by. Here are some things you can do to get Sealed Tubes (Echo EXP materials) in the game.
10 WAYS TO GET ECHO EXP FOOD Wuthering Waves Guide
Sealed Tubes are difficult to obtain because they can only be farmed through instances that require Waveplates, meaning you’ll need to carefully manage your energy and balance Resonator and Echo upgrade farming to strengthen your account. Below are some of the most accessible ways to obtain Sealed Tubes in Wuthering Waves.
In the Forgery Challenge section of the Guidebook, head to the Tacet Field Cleanup section to find a list of all available Echo farming fields in your world. These are open-world Domains where you must defeat waves of TDs and use 60 Waveplates to claim rewards including Tuners, random Echoes, and Sealed Tubes (Echo level-up materials).
Tacet Fields offers the best Waveplate to Sealed Tube ratio while also allowing you to farm other materials needed to upgrade your Echoes. I highly recommend farming these whenever you can. To get the best rewards, try to level up your SOL3 Phase (world level) as soon as possible to increase the amount and quality of the reward.
