Heres what Strymon say about the AA.1...
AA.1 is designed to be your bridge between the world of guitar pedals and the world of Eurorack modular. This compact 4HP amplifier attenuator module has everything you need to interface your modular with your guitar effects pedals as well as with your guitar or bass.
Merge guitar with modular.
AA.1 is purpose built to combine your guitar gear and Eurorack modules in just about any way you can imagine. Connect a pedal to the effects send and return of Magneto. Use your guitar or bass as a signal source for mangling and warping with your modular gear. Send an instrument level stereo master output from your modular rack to your computer audio interface.
On the level.
AA.1 is designed to solve all the issues that arise when introducing guitar gear to the world of Eurorack. Most Eurorack modules output very hot audio signal levels that can easily overload the inputs of effects pedals or computer audio interfaces. And it’s not just the output of the modules: Audio inputs in a Eurorack system also need to receive hot signals. AA.1 amplifies the input and attenuates the output signals to the appropriate levels.
Easy to use.
AA.1 is straightforward to use. The 1/4″ stereo input amplifies guitar level signals by +18dB, outputting the amplified signal through left and right 1/8″ outputs (use the left output for mono). Left and right 1/8″ inputs attenuate Eurorack level signals by -18dB, sending the attenuated signal through left and right 1/4″ outputs suitable for outputting to guitar level products.