Saturday, December 24, 2022

Cloning the Fulltone OCD - The Ominous Carnivorous Dinosaur!

Founded in 1993, Fulltone made a variety of pedals over the years and was in many ways at the forefront of the boutique pedal market - in the US at least. The owner had been mired in some recent controversy and announced in August 2022 that it would be closing shop. If you go to the company website now, you get a Looney Toons "That's All Folks" banner, and that all of the individual pedals (which had been marked down) are sold out. The Fulltone OCD was a very popular overdrive pedal that, much like many popular pedals, underwent several parts transitions over the years. There are several variants, but I wanted to focus on some of the 1.X variants initially - especially the 1.4 which threw in a Germanium 1N34A transistor.


For these first builds, I teamed up again with South Obolon FX. He created a special version of his Disorderly Drive board with the Steggo name and the Steggo pedal name, "Ominous Carnivorous Dinosaur," on the silkscreen. The build was straightforward. Although the vintage pedals appear to have used carbon film resistors, I went with 1% Yageo 1/4W metal film resistors for this build. The film capacitors are a mix of Panasonic and KEMET, and the electrolytic capacitors are all Nichicon. There are two new production 2N7000 transistors for the mosfet clipping, and there are a couple of red LEDs (and a switch) to switch to an LED clipping mode. There is one TL082 Op Amp - this particular one is from a set I found at the local electronics parts store. I only have two or three of them, and they'll likely all find homes in these builds.


Once again I'm wiring everything to the board rather than using a star ground on the input jack, but I'd pre-wired the input and output jack grounds to the board, which means I needed a bit more length to get the heat shrink tubing over the ground connections - unlike my recent Duo Phase build with amazingly short connections. The LED is wired off board, as is the SPDT HP/LP mode switch - though the current limiting resistor for the LED is actually on the PCB. This arrangement provides you a lot of flexibility for placement of switches and the LED, which I (of course) used to optimize the enclosure art!


The dinosaur art, an Allosaurus, for the "Ominous Carnivorous Dinosaur" pedal was done by a Ukrainian artist, @estelkatrin. She's not only incredibly talented, she's also a wizard with Adobe Illustrator, so I'm able to import the art directly into the Tayda UV print templates for the enclosures. Once I brought "Al" into the template, the rest of the art was a multi-way collaboration.

Once I got the pedal going, I realized why people love these older OCD models. It is absolutely amazing. If you turn the gain down, you can get an almost Klon-like boost, but if you turn it up, then you're in 80's metal guitar range. That makes this a very versatile pedal, which can cover a lot of tones in one box - so this is likely to find a permanent home on the board!

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