Take the Bypass - P2 Clone - Now With Cornish Bypass

A little less than a week ago, I posted a build of the Cornish P-2 as traced and published by Effects Layouts. For that first build I used a PCB Guitar Mania 3PDT stomp switch board as I wanted to make sure that the PCB itself actually worked. That build quickly became one of my favorite pedals, so I wanted to take the next step and try it with the actual Cornish Bypass (originally traced as part of Effects Layouts G-2 project). I am hoping to offer a few of these for sale in the not so distant future, so I wanted to make sure the board worked properly with and without the Cornish Bypass.

As you can see from the photo above, it pretty much looks like the previous build. I'm using different MLCC capacitors and one different electrolytic capacitor. Eagle eyed individuals will note that there was a mistake on this build that I didn't catch, well, until I actually started on the blog entry. It's fixed now, but the mistake will persist in the photos (one of the electrolytic capacitors is reversed - fortunately it never got enough juice to cause an issue). Once again I'm using pretty much all new components, except for the Panasonic film capacitors - which are just nice film capacitors, so I tend to use them a fair amount.

The bypass board is a bit smaller, and as you can see rather than using a 3PDT stomp switch, it uses a 2PDT. That means any builds with the Cornish Bypass are going to draw on a different stock of stomp switches than what I use for 90% of my other builds. I'd initially thought the component side would face down toward the bottom of the enclosure, so I placed one of the electrolytic capacitors on the other side to ensure that there was enough space, but as it turns out, it works better if the component side faces the top of the enclosure - so in future builds all of the components will sit on this side.

When I first got the build together, the LED came on when I checked it with my "spaghetti tester", so I moved on to the sound check. The bypass worked fine, but I didn't get anything with the pedal actually on. I pulled out my audio probe (also visible above) to track down the issue. It turns out I had only soldered one of the two leads of one of the capacitors. Once that was fixed, the pedal appeared to function normally (and pretty nicely at that!). I'll have to double check what the function of the capacitor I had reversed was as the pedal seemed okay without it. It could be a power supply filter capacitor.

I decided it would be worth it to show off the actual interior of one of these builds. They aren't as neat and tidy as the back-side of manufactured PCB by any stretch of the imagination. I also tend to use more wire than is strictly necessary simply because it makes it easier for me to get everything actually connected. As I'm moving toward (very) low-volume commercial production, I've been trying to add some features like shrink-wrapping all of the off board wiring to the DC, input, and output jacks. Most of them are fairly straightforward, but the +9V is two wires in this build, and the star ground is four wires - which requires a bit of dexterity to not only get soldered in, but then shrink wrapped as well.

The graphics on the enclosure (above) are the same as on the earlier version of the pedal, but this one is dark gray rather than black. Cornish pedals seem to have come in both colors, and I decided to use black for the ones with a standard 3PDT switch, and gray for those with the Cornish Bypass. I ran out of dress nuts for stomp switches, but I'll add one once my order arrives.

So, there you have it! I've since fixed the reversed capacitor, but as it's fairly late I haven't had a chance to test it out yet. As the pedal was working before, I don't envision any issues, but I've been surprised before. I'm hoping to make 2 or 3 of these for sale in the near future, but I need to etch some more PCBs. Once they're available, I'll post here and on the official Steggo Studios Facebook page.