The Making Of the APH-12
Hawker’s Log: The story of the Purple Phaze
The APH-12 has been a long story of development ups and down. We have resorted to calling it the Lemony Snicket product due to the never ending series of unfortunate events that came up in it’s design and manufacturing stages. Below is the story from the manual and a video about the making of the APH-12.
For more information, videos, manual etc about the APH-12 click here.
Taking nearly 3 years to develop, the APH-12 has been the most challenging design to date for Asheville Music Tools. A 12-stage phaser has been our most requested product, yet I really didn’t know what I could bring to the table to make it special. I’m not a huge phaser user, and the previous “benchmark” wood sided 12-stage phaser I worked on had a high parts count and expense. I wasn’t sure that a worthy phaser would fit into a friendly enclosure size or be manufacturable at an approachable price point.
Usually when I design a pedal, we hash out the features as a team. I then run simulations to have some idea where I’m going and how I’m getting there. In this way, the first effort comes out close to production ready. We build a proto, I make some tweaks, and it goes to production on the 2nd attempt. Since this time the project felt so undefined, we started by first designing a massive development board where everything was on the table. We didn’t even try to make it a product. It had knobs and switches everywhere to control each stage including summing and phase selector switches, options to put the stages in parallel for barber pole operation, and even hooks for digitally controlled fancy modulation and multi-phase LFOs. I really thought this was going to be our first hybrid digital-analog product and started with that assumption. I tested different resonance and summing networks and had grand plans for a very complex phaser. But none of that impressed the team. We were surprised to learn how much we loved the mostly unexplored character of 3 and 5 stage phasers, out of phase summing, or the utilitarian tremolo-like sounds of 1 and 2 stage phasers. Then we discovered how some good “Jerry style” responsive envelope control inspired us. So, in the end, we went back to the basics.
Based on this exploratory phase, I began to spin the first prototype. It was a long development cycle as I struggled with the controls. We had many rounds asking what features do we put in, how do we get this down to 6 knobs and 2 switches? Can we find a stage selector switch we like? And even then, I was not sure we could fit it in a single enclosure or make it affordable. Very little of the infrastructure I designed for previous products was reusable. I redesigned the power, the entire audio path, and control the voltage topology to work with a new bi-polar power system. We had to change knob and pot styles to accommodate the switches and search for new vendors. There were new, smaller affordable parts that we had not used before to try. But after many months I came to the sad conclusion this was not going to work, and I scrapped the design before it even saw prototype. Scrambling now, I decided to risk trying a filter IC that was really intended for something completely different. If it worked it would save enough space and cost to make this viable. Alas, the first prototype with this part was a heartbreaking and demotivating failure. No one we knew of had tried to use this chip for a 12-stage phaser before, and what we created was not up to my standards. The company that designed the chip tried to help, but they too had no idea why we were experiencing the problems we did. What worked sounded very good, but so much didn’t work to my liking that I didn’t see a path forward.
After many months working on this 3rd attempt, I thought I had found a work around to the largest obstacles. At this point my prototype boards were too hacked up to continue with, and my idea to fix it was near impossible to verify with the existing boards. I took a risk and spun the 4th version. And bingo! The last problems were solved, though we had to throw money at it to do so. Now with the showstoppers past us, I could move on to the real refinement process. Although some said it was good enough, I wasn’t happy, and I wanted to incorporate the great ideas and insights from our testers. So, I hacked and hacked, often with no progress for weeks. Then Hurricane Helene devastated our town and shut us down for three months while we focused on taking care of each other. But, right about the time I was feeling defeated, I made a few discoveries and completely redesigned the saturation and envelope follower circuits. It was such a radical change at the 11th hour that I wasn’t sure if I missed the old sounds, or it was just so new I had to relearn it. Thankfully, our testers felt the latter. When one of our employees told me he came in early and was inspired to jam out to music that he normally didn’t play, I knew it was ready.
Feeling like I had now got it, we spun the PCB a 5th time: over two times as many versions as we ever had needed before. What you see before you is the culmination of 3 years, a huge group effort, and many grey hairs. I hope you find joy in our efforts and find it as inspirational as we have.
Hawker
