ChewBlogga: Boss FS-6 Power Mod

I was getting frustrated with having to yank the 1/4" cable from my Boss FS-6 foot switch every time I was done playing. I decided to embark on what I thought was going to be a simple project to add a power switch to the unit. Unfortunately, my 2 hour project ended being more like 10 hours. I'm documenting it here so anyone out there decides to do this, they'll hopefully avoid my mistakes.

Here goes...

Although I started out wanting to add a power switch only, I decided to add a switching DC power jack as well. This is what I bought...but...oops...

The DC power jack I bought won't work. All Boss pedals (almost all pedals for that matter) use a negative center tip and the chassis of this jack is conductive and since it will end up being positive, I can't mount it to the foot switch chassis assuming it will be used for ground. Back to the store for a plastic DC barrel jack...

I decided on a flush mount DC barrel jack thinking it would look nicer...another mistake. After mounting it, the jack sits too far inside the case of the FS-6 so that when you try to assemble the 2 halves back together, it won't close properly. Buy this DC barrel jack instead please and save yourself a whole lot of headache.

Ok...I also had a lot of problems even with this DC barrel jack and after much trial and error, I finally figured out what I needed to do to make everything fit and for the case to close properly. Using a sharp X-Acto knife, cut off the edges of the jack as follows...

As you can see, I shaved off 3 sides. By the way, the image of the cut DC barrel jack is upside down. You want to install it into the chassis with the center pin connector facing up. The center pin connector is the one that looks different than the other two. The top is is required so that the PC board of the foot switch will clear the jack. One side needs to be shaved so the polarity switch is accessible and the other probably wasn't necessary but I wasn't sure if it would clear the side wall of the foot switch chassis so I did it anyway.

Ok...now that we got that all out of the way, here is what I did to get everything going. First off...the schematic. The S, B, and T in the diagram represents the 3 connectors of the DC barrel jack.

The way this is wired up, there is a master On/Off switch but if you unplug the power from the DC jack, the battery will still supply voltage to the foot switch. Here are pictures of the wiring test. You can see in the first picture, the voltage is supplied by the barrel jack at the top of the image producing 8.94vdc. The next image shows the jack unplugged and now running off the battery which is producing 9.61vdc.

Ok...time to start drilling and mounting everything. I used a step drill bit to drill the back of the foot switch chassis. Unfortunately, I was so wrapped up in the process, I forgot to take pictures of the drilled out chassis before I assembled it. I was too lazy to take everything apart after. Hopefully, you get the idea by looking at the assembled images.

In put the power jack on the left side (if you're looking at the rear of the foot switch) and the switch on the right. You have to measure the center of the DC side perfectly. There isn't a lot of clearance on the back face of the foot switch chassis after you drill out the correct size hole. In fact, you'll notice that the barrel jack is slightly elongated and not a perfect circle. I took a rat tail file and filed the hole a little bigger on the top and bottom sides and left as much metal as I could on the side.

As you can see from the picture, I put some shrink tubing on the DC jack since the wires would be in close proximity. I didn't want an accidental short. I also used some duct tape to tape down the wiring to try to keep it neat.