I have an ancient MXR Phase 90 from about 1990 or so which has an old style DC jack socket (1/8″). For this reason I’ve been using it with a battery. So, today it was time to whip out the drill (the hole needed widening and, boy, did they use proper metal back then) and the soldering iron and fit a modern 2.1mm centre negative DC jack socket. Success!
Here’s a pic of the guts before I converted it:
The battery leads are disconnected. But I won’t be using a battery in it any more…