Invoking the Spirit of EVH - the Wolfgang 5051

Despite passing away a little over a year ago, Eddie Van Halen remains one of the most influential rock guitarists of all time. I was a huge Van Halen fan in my youth, and one of my first concerts was their 5150 tour (the first with Sammy Hagar as lead singer). As is common with many prominent musicians, Eddie worked with various companies to develop his own lines of gear including guitars and amplifiers. Starting in 1993, Eddie worked with Peavey to develop the 5150 series which was produced until 2004. He then moved to working with Fender on the EVH line of amplifiers which were first released in 2007. This particular build creates essentially a preamp effect based on the Peavey circuit which can be used either as a pedal directly or in an effects loop - though with the sheer output it seems far better suited to the latter!

As with most PCB Guitar Mania offerings, their Wolfgang-5051 (see what they did there?) board is incredibly dense with all of the components packed together just about as tightly as possible. This has a couple of immediate consequences. First, your soldering skills really need to be up to the task. Second, if you're not able to find components with the exact dimensions indicated on the silkscreen, you're going to have to get creative. Fortunately I was able to find just about everything I needed in the correct size - except for that electrolytic capacitor which I had to angle over to fit in the enclosure. I also went ahead an insulated the exposed leads since they were fairly long!

The build instructions for the 5051 give you two options - one stock, and one "high gain" modification which provides more distortion potential. Given those two choices, I of course chose to go the "high gain" route! I did, however, run into a little snag in building the pedal. The high gain modification not only involves changing the values of some of the resistors, it involves adding an additional resistor (R46) and capacitor (C30) to the build. If you look through the diagram of the PCB above, you'll note that neither R46 nor C30 actually appear anywhere on the silkscreen. However, it was clear from the circuit diagram that R46 was in series with C23 and C30 was between R31 and C21. Big shout out to Gonzalo Segovia from PCB Mania for verifying the connection points. If you look at my PCB in the enclosure below, you'll see C23 (next to the IC bottom right) is higher than normal because it has R46 soldered underneath it on one of the legs. The capacitor at a right angle to it above is C30 attached to R31 and Vb. The build documentation for the project has been updated to show these connections in the most recent revision!

While the enclosure looks fairly roomy, these are a bit shorter than the 125 boxes I'm used to. However, I did manage to get everything to fit just fine. The PCB itself is compact so there is plenty of room to run all of the connections - though I wish there had been a little more space between the PCB and the 3PDT switch - that part is fairly tight. In retrospect, I could have likely bent the leads to the pots back a bit to create more room.

For the enclosure I decided to have a bit of fun and go Viking / Norse with it. I found some appropriate art and a font online and went from there. I've actually done runestones both in slate and designs on paper in the past, and in retrospect I think I may have missed an opportunity to create something very unique on my own here. Maybe I'll look at that for a V2.