I've also made the guide below into an article, here: http://www.head-fi.org/a/how-to-find-the-tokyo-e-earphone-shop
I think I need to make a video guide on how to get to e-earphone. The difficulty is finding the entrance to the building which has their orange sign.
The red writing on the road across the middle says "Chuo Dori". It's the huge main road. The train line on it is a subway.
The small orange box is the building e-earphone is in. The big pink building to the left of it is the very large, black building.
The entrance to the orange building is on the road it is touching. It has a sign outside with the names of the shops inside, including the e-earphone one. There's no door, you just walk past the sign into the building to the elevator and take it to the 5th floor.
Here's google maps. Note that the orientation of the map has Chuo Dori vertical.
From Akihabara station, you want the opposite side of the train lines that Yodobashi is on.
I've marked the big black building as "Hall" as that is where the e-earphone festival is held.
This is an old, google street view picture of the entrance. Instead of the orange DVD4649 sign, the 5th floor sign will now say e-earphone.
Here is a bunch of us standing in the entrance way to the building:
