Rainbows and Unicorns? PedalPCB Leprechaun Build

Fingolfen

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Build Rating
5.00 star(s)
So I got a request for a Rainbow Machine in dino form, plus I wanted to get one together for myself, so I figured it was time to finally take the plunge...

PedalPCB Leprechaun - Dazzling Dilophosaurus - 01.jpg

For this build I used the PedalPCB Leprechaun board. The effect is purely digital and it is based on a stock usage of the Spin FV-1 chip (as opposed to one that needs a separate EEPROM chip with algorithms). The Spin FV-1 is a surface mount chip, with a whole lot of connection points. Since I'm still developing my skills soldering SMD components, I went ahead and picked up one board with the chip already mounted (thanks Robert!!!), and then built a second personal unit where I intended to solder the chip myself. With copious use of flux, I managed to get the FV-1 on my board (below) down reasonably well, which may open the door to more SMD projects in the future.

PedalPCB Leprechaun - Dazzling Dilophosaurus - 02.jpg

The rest of the build follows my normal pattern using a mix of 1% metal film 1/4W resistors, film capacitors, MLCC capacitors, and electrolytic capacitors from Mouser. This one also have a few additional through-hole packaged integrated circuits which I socketed per my normal build technique. The board is fairly roomy as this pedal is designed for a 1590BB enclosure (I used a 1590BB2 as it has extra depth).

PedalPCB Leprechaun - Dazzling Dilophosaurus - 03.jpg

There is a bit more hand wiring on this particular build than on many of my recent builds. In addition to the normal active / bypass stomp switch, the pedal has a "Magic" setting which is activated by a second stomp switch. That second stomp switch is hand wired, though it is only four connections (that being said, I tend to use aviation grade wire, and hooking up a stomp switch with solder lugs with aviation grade wire can be a royal pain in the butt!). Another feature is the expression jack. This feature allows you to connect an expression pedal to the effect to effectively control the pitch (spectrum) rather than adjusting the knob.

PedalPCB Leprechaun - Dazzling Dilophosaurus - 04.jpg

I wanted to come up with something suitably fun for the enclosure on this one, so I went with a very dazzling dilophosaurus - the Jurassic Park film variety rather than a more scientifically accurate one. The background imagery has light going through a prism to provide a bit of a throwback to the original "rainbow machine" name of the pedal.

In terms of sound - it is almost impossible to know where to start. Nothing that comes out of this pedal is ordinary or analog. You can get a pretty shimmery digital chorus if you set a lot of the knobs to noon and turn on the magic / dazzle - but from there it gets really crazy. For me this is an entirely situational pedal if you're trying to do some sort of specific way out there effect, but it is really cool nonetheless!

Tiny bit more at the blog: https://steggostudios.blogspot.com/2023/08/rainbows-and-unicorns-cloning-rainbow.html
 
Literally started one of these boards earlier tonight! 3rd pin in and I bridged a couple legs…. Took me a couple tries with some braid to wick things back to normal…. Ended up changing my tip from a standard conical to a fine point…. I had thought I should set up the tip but I got lazy and just went for it 🤣
 
Literally started one of these boards earlier tonight! 3rd pin in and I bridged a couple legs…. Took me a couple tries with some braid to wick things back to normal…. Ended up changing my tip from a standard conical to a fine point…. I had thought I should set up the tip but I got lazy and just went for it 🤣
I'd had some mixed luck with bigger tips early on, so I just threw in the towel and use my fine tip and really thin (0.4mm if memory serves) solder for most components on a through hole board. I'll then go to the bigger solder for off board components.
 
This one will be next for me to build. For the Expression Pedal jack, what type of jack is required? Just a typical stereo TRS jack?
 
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