I am trying to build my first headphone amp now, the Pocket Headphone Amp from the Headwize.com project library, as I anxiously await the arrival of my first pair of real headphones, the Sennheiser HD580. 
This little amp's schematic says to use a 9-volt battery, but I keep seeing posts on here for people using AAs. I'm curious what the pros/cons of each are.
Aren't AA batteries heavy and don't they take up a lot of space?

This little amp's schematic says to use a 9-volt battery, but I keep seeing posts on here for people using AAs. I'm curious what the pros/cons of each are.

Aren't AA batteries heavy and don't they take up a lot of space?








