I decided that I wanted to know what the Yamaha THR10C sounded like through external speakers, so I started the project Saturday. I found a 2X12 SS Combo cheap on CL with 8 Ohm speakers in it, so that was my first step. I disconnected the internal amp and wired up two separate jacks to plug into from the outside. I put the Yamaha on the bench a couple of days ago and opened it up just as an exploration to see how tight it was going to be. Went to the electronics store and picked up some switching jacks, some plugs and wire. Made up two new wires from amp to cab, and then started laying out the switching jacks, the speaker wires inside etc. and got it all straight in my mind of how I wanted to do it. Finished it up just a bit ago. I am always nervous when I first turn an amp back on after I've been inside it thinking about all the things I could have screwed up, but it fired up and no smoke. It wasn't terribly hard to do, but for me any way requires a lot of planning and concentration. It is a tight fit, but it will work. The internals worked as before, so I hooked it up to my "new" cab. The difference in sound is night and day. Volume is considerably louder, and full rich sound with all the bass that's missing from the internal speakers. You remember the sound of this amp in the demos on youtube? This is what it sounds like in all those demos that were mic'd up and run through a PA or recorded directly and then played out through a "sound" system. I love this amp just as it is, but wanted the option to play it with "jamming" volume with my friends. I realize, that I have voided my warranty by doing what I did, but it was worth it for me. I took pics all along the way, but probably won't post them until some time tomorrow.