I've been a long time Boss OD-3 fan, using it off and on over the years. Less-so in recent times, though, one of the reasons being I always wished the gain could go just a little bit lower. That is, depending on pickups or what comes before it, in stock form, it may be impossible to get a clean boost or edge-of-breakup sound. Until, in his great analysis, @Chuck D. Bones mentioned a trivial mod for getting the gain to go lower: reduce r38 (on the J Luja schematic; R14 on the Aion schematic) from 3k3 to 1k. I first did that on my actual Boss OD-3, found it to be what I always wanted, so set out to create a DIY Boss OD-3 using Aion's Heliodor PCB.
There's a YouTube guy, Michael Banfield, who has done a lot of Boss OD-3 videos. He does the pedal more justice than I can!
The build was straightforward. I was worried about making a mistake, as I was building this, the Madbean Blue Steel (Boss BD-2), and a couple PedalPCB boards all at the same time. Neither Aion nor Madbean put component values on the PCB silkscreen, so I was working off a BOM for this and the Blue Steel. And the two pedals have a similar number of components. So I was constantly worried that I'd accidentally swap components between the Heliodor and Blue Steel. The Blue Steel still needs to be boxed up, so I haven't yet tested it. But I played my Heliodor and actual Boss OD-3 side-by-side, and they sound more or less the same.
As with my just-posted Celestial Drive build report, I used "v3.0" of my custom microcontroller-based relay bypass. One of the features I added in this PCB revision was a footprint that supports two different relays. I used one relay type in the Celstial Drive, and the other for the Heliodor. Both work, yay!
Aesthetically, it's not quite as pleasing as I had hoped. I used the Tayda "silver hammer" enclosure, which I think looks awesome. No labels, ala @MichaelW. But you can see my drilling wasn't too precise here. Also, my relay bypass board is in an awkward position, which was necessary due to that big cap on the lower-left corner of the Heliodor. But it works and sounds good, so I'm not going to stress over the aesthetics.
There's a YouTube guy, Michael Banfield, who has done a lot of Boss OD-3 videos. He does the pedal more justice than I can!
The build was straightforward. I was worried about making a mistake, as I was building this, the Madbean Blue Steel (Boss BD-2), and a couple PedalPCB boards all at the same time. Neither Aion nor Madbean put component values on the PCB silkscreen, so I was working off a BOM for this and the Blue Steel. And the two pedals have a similar number of components. So I was constantly worried that I'd accidentally swap components between the Heliodor and Blue Steel. The Blue Steel still needs to be boxed up, so I haven't yet tested it. But I played my Heliodor and actual Boss OD-3 side-by-side, and they sound more or less the same.
As with my just-posted Celestial Drive build report, I used "v3.0" of my custom microcontroller-based relay bypass. One of the features I added in this PCB revision was a footprint that supports two different relays. I used one relay type in the Celstial Drive, and the other for the Heliodor. Both work, yay!
Aesthetically, it's not quite as pleasing as I had hoped. I used the Tayda "silver hammer" enclosure, which I think looks awesome. No labels, ala @MichaelW. But you can see my drilling wasn't too precise here. Also, my relay bypass board is in an awkward position, which was necessary due to that big cap on the lower-left corner of the Heliodor. But it works and sounds good, so I'm not going to stress over the aesthetics.
