Mercury Magnetics Champion 600 Build

Lucky for us, Duncan documented nearly every step of the build process with pictures so we could have a look at the transformation of the amp. You can see his pictures in all there glory at the left hand side of the page, no doubt these would be useful if you are going to do this modification yourself. I asked Duncan if he wouldn’t mind summing up his experience with the Champion modifiation and here is what he had to say:

The MM kit is very well constructed and comes with detailed instructions in a PDF on the included CD.  Overall, the documentation is quite good.

The preceding said, this is not a build that I would recommend for a hobbyist who does not have a basic understanding of circuitry, strong soldering skills, a digital soldering iron, a circuit-board holder, a Dremel, and a well-lit workspace.  As you can tell in the photos, I used a Weller WESD51 digital soldering iron and a Panavise board holder, both of which worked particularly well and allowed me to stay focused on the build at all times.  I just can’t stress enough the value of a high-quality iron and board holder for a project like this—particularly if you are an amateur project-builder who hates to suck up a blown solder joint

I started by laying out the assorted parts and then separated the smaller electronics parts into a clear tackle box, giving each part-type its own slot in the box and labeling them by writing on Scotch tape on the top of the box.  The Mercury Magnetics PDF part list was clear, and I didn’t have any difficulties identifying parts.

After getting everything inventoried, I cracked the amp case and just followed the PDF instructions on a laptop set up next to my work surface.  While the screen resolution wasn’t as high as a printed-out version, I found it useful to be able to scale the photos.  Once into the build, there were a couple of points where the instructions weren’t completely obvious to me, but in each case, I was able to study the photos, think about the circuit, and push through.  And, I have every confidence that other builders might not even find those points challenging.  The build does require you to replace the original transformers with two new MM transformers and a mini-choke, drilling new mounting holes.  MM provides a printable template, which was very helpful in measuring and drilling the required new mounting holes.  The builder must also remove, replace, and augment significant amounts of the original circuit, including breaking traces and drilling new contact points along a couple of paths.  This was a little stressful, frankly, but accomplished with a Dremel.  Otherwise, replacing the speaker and reassembling the case was as easy as you might imagine.  I also sourced vintage tubes from local amp builder and switched them in during the build.

I should note that the MM instructions give an option at one point of wiring the new circuit for volume or tone.  I chose to wire for tone, but was stunned at the improvement in volume that resulted anyway.  I will leave it to the Guitar Fixation editors to give their much more qualified opinion on the result.

Finally, I am guessing an professional amp-builder could knock this kit out in 2 hours; it took me about 5 hours, start to finish.  I had a great time and encourage any experienced electronics hobbyist to take a crack at the Mercury Magnetics Champion 600 kit—it is incredibly gratifying to play guitar through a circuit that you soldered yourself!

Be sure to check out Duncan’s handy work in our Champion 600 shootout!