Aion Oceanid - Cornish OC-1 Optical Compressor Adaptation

Here's a project I literally finished up last night. Granted, the PCB had been populated a couple of weeks ago, but it took me a while to get the enclosure to a point where I was happy with it. The Aion Oceanid is quite a bit more complex than Acapulco I detailed in my previous blog entry, and is an adaptation of the Cornish OC-1. This brings me to one of the major benefits of building your own guitar effects pedals. The cheapest I've seen a Cornish OC-1 for sale is about $750. Some Cornish pedals blast through the $1000 mark. The Aion PCB will cost you $12, and the rest of the components (assuming you get good quality ones) should run you $50-$60, meaning you get a boutique pedal for an order of magnitude less cost - assuming you're willing to put the time in to build it.

While not the most complex PCB I've worked on, this one is fairly busy with a large number of resistors, capacitors (film and electrolytic), a trimmer resistor (more on that in a bit), four integrated circuits, a couple of transistors, and the one vital component you can't see (because it's on the back of the board at the top), the vactrol. The vactrol is a combination of a light emitting diode and a photoresistor. Essentially it is a voltage controlled resistor, the more current that goes into the LED the more current that can pass through the photoresistor. While this design only includes one, there are some other designs I've got in the works with multiple photoresistors - and some in fairly unique configurations.

Although Aion has another project called a "Blueshift" - I decided to use that name for this build. Light waves are subject to a doppler effect just like sound waves, and when light (optical) waves are compressed, it is called a blue shift. I purchased a 125B enclosure from Tayda Electronics and had them custom drill it to the specifications in the PCB instructions from Aion. I went to one of my default sources for decals, Scumb4g Kustoms, to make the decals for this project. I'd initially made decals that would cover a whole side, but they proved difficult to apply, so I ended up cutting them apart and then using a copious amount of gloss covering.

The electrical components all came from Mouser Electronics. Aion is very good about providing spreadsheets with recommended high-quality components that should give you a reliable and durable build. As you can see from the photos above and below, the pedal proudly displays its Steggo markings on the top and bottom. While you can't see it from the photos, the LED I chose for this particular build is blue as well.

I've only gotten to play with this pedal a little bit, but with the "volume" control I do get a little bit of hiss at high levels meaning I've got some noise in my signal chain somewhere. That being said, the compression and sound is absolutely amazing. I may still have a little dialing in to do as well, because that internal trimmer resistor adjusts the response. I set it at the default 25% initially and have since adjusted it to about 40%. I may leave it there or I might experiment a bit more. Once I get my A/B Box complete I want to run it up against my MXR Dyna Comp pedal, because at this point I think I actually like this one a lot better.