Another New Design - The Falcarius Overdrive - Modified TSV808 With 3-Band EQ

As I mentioned yesterday in my entry on the Kosmoceratops, I've moved from simply populating boards laid out by 3rd parties (either professionally or by request) to boards I've laid out myself. One of my all-time favorite pedals it the TSV808 (the Secret Spinosaurus in its dino version), so when I found that "Chuck Bones" of Celestial Engineering had worked with others on a modified version of that circuit with a 3-band equalizer, I knew I had to try laying one out myself.

I actually laid out this board before I laid out the Kosmoceratops, so it doesn't incorporate all of the refinements I've made in terms of spacing for the ribbon cable, but is otherwise pretty solid. I based it on the most recent revision of the Timbre Man (Version 2.2.2 from April of this year) on the PedalPCB forum. In discussing the layout on the forum, Chuck emphasized that it was important to keep the traces to the op amp short to prevent oscillation in the circuit, so I dropped the op amp pretty much in the middle of the board and worked out from there trying to keep anything that connected to it close-by. With five potentiometers, getting those laid out was entertaining as well, so I decided to rotate the volume and drive pots to keep all of the controls effectively in a "T" shape at the top of the board. As you can see below, I also added some Easter Eggs to the back side of the PCB, "because who doesn't love dinosaurs?"

Once I got the boards in, I went ahead and started populating my first prototype. I used all 1% metal film resistors (Yageo) in the build. The film capacitors are a mixture of WIMA and KEMET. I went ahead and used MLCC capacitors for the lower value ones, though silver mica capacitors could be used instead. I may experiment in the future on whether they make much of a difference. Three of the diodes are new production, but one is a NOS 1N34A. I went ahead and splurged and used an OPA2134 op amp rather than the vanilla TL072, as I had several on-hand that I use in my Spinosaurus builds.

Once the board was together, Steggi was very keen to test it. This was actually the first of the boards I'd laid out that I finished a prototype for, so there were a lot of fingers crossed hoping the board would work. It fired up beautifully the first time. The very first thing I decided to do was compare it to my TSV808 clone in terms of noise level and performance. The shared DNA is very clear, but I really love the 3-band EQ - it allows you to shape the tone more precisely than the treble and bass knobs on the TSV808 (and that's even with the Tone Geek board moving the bass control to the top, as opposed to it being an internal trimmer you had to access through a hole in the enclosure on the real thing). 

At that point it was just a matter of getting the board boxed up and into an appropriate enclosure. I designed this board to have the LED on the daughter board, so there is only an LED connection. The CLR and LED itself are therefore not on the main board. I decided to go with a fixed LED brightness on this build as well rather than including the brightness trimmer. The jack connections are all insulated in heat shrink tubing as well.

For the dinosaur mascot, I'd initially thought to call it the Timimus Overdrive. I'd even found a really amazing piece of dinosaur art that would have worked well with the enclosure, but I changed my mind for a couple of reasons. The Timbre Man and Timbre Man Boneyard edition sort of follow a lineage back to the Timmy 3 pedal, and Timimus was a little "on the nose" name-wise. Second, I tried for about 3 weeks, but couldn't find a way to get clear permission to use the dinosaur art I wanted to use, so I decided to make a name (and dinosaur) substitution - hopefully for something in roughly the same family (or with a similar silhouette). Enter, the Falcarius! According to Wikipedia:

Falcarius (meaning "sickle cutter") is a genus of primitive therizinosaur dinosaur that lived during the Early Cretaceous period in what is now North America. Its remains were first collected in the Cedar Mountain Formation in 1999, with subsequent findings made during the 2000s. The genus is known from multiple specimens ranging from immature to fully-grown individuals. Falcarius was a 4 m (13 ft) long bipedal herbivore with a small head and an elongated neck and tail. 

The rest of the enclosure follows the "Greek" theme that I've used on a couple of recent pedals - all of which at this point are ones that are either original layouts or modifications of the original circuit. I think I may need to add a chorus to this lineup so I can have a "Greek Chorus" pedal.

I'd initially used 1611 16mm knobs like I'd used on several other pedals recently, but given the number and tightness of the controls, I think I may move to the 15.5mm "Omnibot" knobs. Not only are they a little easier to use, if you look at them in profile, they sort of resemble the base of a Greek column, if you squint your eyes a bit. In terms of where this pedal stacks with my other tube screamer pedals - it immediately jumped into the Top 3, and I think it may nudge ahead of my Tone Geek Valve Screamer (the Velociraptor Screamer) right behind my TSV808, but it's really splitting hairs at that point.