Taking a Guitar Pedal From Concept Into Production


Starting a new project is fun, and often involves great times spent playing with breadboards and protoboards, and doing whatever it takes to get things working. It can often seem like a huge time investment just getting a project to that functional point. But what if you want to take it to the next level, and take your project from a prototype to a production-ready form? This is the story of how I achieved just that with the Grav-A distortion pedal.

Why build a pedal, anyway?

The author, shown here with bandmates.

A long time ago, I found myself faced with a choice. With graduation looming on the horizon, I needed to decide what I was going to do with my life once my engineering degree was squared away. At the time, the idea of walking straight into a 9-5 wasn’t particularly attractive, and I felt like getting back into a band and playing shows again. However, I worried about the impact an extended break would have on my potential career. It was then that I came up with a solution. I would start my own electronics company, making products for musicians.

I experimented and worked on a variety of projects, sometimes with friends, sometimes alone. After exploring a variety of options, I decided that a simple distortion pedal would be a great product to start with. They’re simple, parts are cheap, and there’s a huge number of ways you can play with the design to create all manner of sonically delicious results. The product would be known as the Grav-A – the first product of my nascent company, Grav Corp.

I Love It When A Design Comes Together

I began the journey by looking to the past, remembering that I’d attempted such a build at the tender age of 18. My former attempt at a guitar pedal was a mess of loose wires, assembled largely with salvaged parts and the meagre selection of potentiometers then available at Dick Smith Electronics (think Australian Radio Shack).

This youthful experiment from years past looked like a pig and squealed like one, too.

There were serious noise and grounding issues and the pedal only worked intermittently at best. I used this as an inspiration to do better, and threw myself into research.

The Internet is a wonderful resource, and provided me schematics and guides to not only existing pedals, but also the best way to approach striking out on your own. There was a particularly early lesson I learned here. It’s often that people will decry the high price of musical equipment, citing that the average pedal uses only a handful of cheap components. In some ways, this is true, but it fails to look at the whole picture.

A commercial guitar pedal may rely on transistors, op-amps and a smattering of passive components to create its sound, and these can be had for absolute pennies, it’s true. But the pedal’s retail price also has to cover the mechanical components, such as jacks, switches and potentiometers, the enclosure, including paint and printing, the labour required to assemble and ship it, and still leave some room for profit to keep the business behind it running. I quickly realised that it simply wasn’t possible to beat the bigger operators on price, particularly if you’re trying to build a robust pedal that can stand up to the abuse of the average touring musician.

After finding some great resources, I settled on using an op-amp gain stage with a Big Muff-style tone knob with a presence control added.  A DPDT switch with centre-off position provided three different clipping diode options – in the feedback loop, output-to-ground, or off. Looking at the rest of the boutique pedal market, I decided to implement a true-bypass footswitch, which, while expensive, ensures that the pedal circuitry can be completely isolated from the signal going to the guitar amplifier when switched off.  I also chose to use PCB-mounted potentiometers and jacks wherever possible, as an aid to quick assembly, and as a way to locate the board within the case. The venerable Hammond 1590BB would serve as the enclosure, painted and printed by a US website specialising in small runs of pedal parts. I had a run of 10 PCBs made at OSHPark, in lovely purple, and built the pedal.

From Prototype to Production

Enclosure artwork underwent many revisions to get everything to line up just right.

The prototype was great and was serving me well on stage, but was too time consuming to build and more fragile than I liked. Particularly egregious was the DC power jack, which didn’t quite fit into the custom machined enclosures. While I enjoyed the pedal and got great feedback from friends, it wasn’t something I could put on the market in its current state, with parts that didn’t quite fit right and artwork that wasn’t dead-on. Another issue was that the the original op-amp I’d used, the LM301, was no longer in production. I resolved to tweak these issues as I moved closer to release.

For the enclosures, I decided to switch to a new manufacturer. The initial manufacturer had poor support and used a highly inaccurate template for artwork and machining. Worse, they requested assembled boards be sent their way in order to make the cases fit the PCBs. This may sound like a solid method at first, however making things “to fit” is poor engineering practice, and added two weeks every time I had to ship them a slightly modified board. The manufacturer I switched to instead worked by using accurate measurements from a supplied drawing and the cases came back perfect. Until I tried, I never realised how much trial and error went in to getting the artwork on such a product to line up properly with the internal components and things like knobs and jacks. A total pain, but rewarding once done.

It’s not exactly CAD, but this drawing enabled the manufacturer to accurately position all the holes on the enclosure. I didn’t enjoy working in inches.

As far as the DC power jack was concerned, I decided to switch to a case-mounted jack, where formerly I had attempted to recreate a modern Big Muff-style setup where the 9 V jack is PCB mounted and clicks into a rectangular hole in the case. This was a major gain, as it made the cases easier to assemble, and the manufacturer found it much easier to drill a round hole than to create a rectangular one.

Other optimizations came in the second production run. I moved both the resistor for the status LED and the switch for the clipping diodes on to the PCB itself. This greatly reduced the number of wires I had to strip and manually solder point-to-point. With all these changes, I reduced production time from 2.5 to 1.5 hours per pedal, estimated.

I begun to implement other techniques to speed production as well. I would take ten boards, and populate them all, then solder them all, then assemble into cases. Batching the operations in stages allowed me to focus clearly on making sure there were as few differences between each pedal as possible, as they were all going through the same production step at the same time.

Headaches

Having pre-orders for the pedal meant there was a time pressure on getting them out the door, which meant I was thrown headlong into the organised chaos that is production. There were lessons that were learned that I hadn’t even remotely expected.

The biggest issue as production ramped up was cosmetic damage. When you’re selling a boutique item for over $150, people expect to receive it in good condition. Having grown up doing projects for myself in my parent’s workshop, my working methods were rough and ready. It was all too easy to drop a tool onto an enclosure or drop a unit on the ground, creating dents, scratches, or paint chips, ruining the finished product. I attempted the dreaded task of reworking these blemished cases, but bar a couple of lucky successes, it was all for nought. This was a huge problem as the cases were costing well over $25 each by the time shipping was accounted for. After dealing with this problem too many times, I revamped my work station, putting down soft foam and organising my tools carefully to avoid inadvertently marring the cases. Simply taking some care in the set up of my work area proved invaluable in reducing these issues.

The first ever Grav-A , serial G-001, sitting centre stage on my pedal board.

Beyond that, shipping was a huge problem. Operating out of Australia, I was stuck paying large sums to import both custom and standard parts. These shipping fees added up and made it difficult to compete on price with

other boutique pedal manufacturers based in countries like the US which had much cheaper access to components and enclosures. This was also a stumbling block on the customer side as well, as it cost a significant amount of money to ship a pedal out of Australia, too.

Finally, packaging  and design issues reared their ugly head. The clipping mode switches were delicate, and a small handful were damaged during transit. The switches would jam up against the side of the box and the shaft would pop out of position when knocked. This was the cause of a couple of costly returns and replacements.

How The Story Ends

Eventually, it became clear that selling a distortion pedal built in one of the farther flung reaches of the earth was going be a difficult prospect to maintain. It’s certainly not impossible, but the guitar pedal market is flooded with thousands upon thousands of distortion pedals, and thus it is hard to stand out from the crowd.

After fulfilling preorders and wrapping up the second major production run, it became clear that the pedal wasn’t generating a significant amount of profit for the time invested. I slowly began to sell down the last of my stock while developing a second product aimed at a different market. Going through the process a second time, I was well prepared to avoid many of the pitfalls that had struck the first time around.

Overall, I can highly recommend taking an electronic project into production. These skills are ones that are best learned by doing. If it’s your first time, choose a project that’s small, achievable, and one that the market has demand for. Aim on getting cashflow as soon as possible to support your operation, and see where it takes you. And of course, most of all, be sure to enjoy the ride!



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