Funbox: "House Sparrow Multieffects"

rwl

Well-known member
Build Rating
4.00 star(s)
This is my build of the Funbox, a DSP pedal from @keyth72. This is an amazing pedal and I'd highly recommend building one, although it's moderately challenging.

After doing a bunch of builds, including FV-1 builds, and reading about some of the more modern pedals (Chase Bliss/Strymon), I started getting interested in trying DSP. My sense is that this is the direction a lot of the industry is heading, and I'm a computer programmer by trade, so DSP in general seemed like a good fit. And fortuitously, I saw keyth's posts on the forum and the thorough build guide, so oI figured I'd take the dip. I liked the small form factor, the many controls available to use (switches, pots, dips, momentary footswitches), and the fact that there were a few different types of pedals already available.

Since most of the face of the pedal is covered in controls, I decided on a small bird. And since the pedal is very versatile (and can "transform" into many pedals), I wanted a "versatile" bird, so I went with the ubiquitous house sparrow. None of the knobs are labeled, since the function of the knobs varies for each piece of software.

The build was mostly straightforward, but I'm giving it 4 stars (for the build, not the pedal). More than any other pedal I've made so far, this required a lot of orders from a lot of places, not just Tayda. Sourcing took a while and there were a fair amount of shipping costs involved, so this was also my most expensive build (the $30 for the Daisy doesn't help). And the build guide was slightly out of data vs the somewhat less thorough github page. I reached out to keyth and he was very helpful and I received a lot of good suggestions. The pedal did fire up right away and I've only had 1-2 glitches that I need to debug - probably my own fault. I haven't used a Daisy before. This is surprising to me given how many steps were involved, including compiling/uploading files over USB. The other challenge I had was not getting everything fully seated. The pedal is quite tall with the Daisy mounted above the main board, and for me it just barely sticks above the top of the enclosure, so the pedal rocks slightly without the back plate. Lucky, the back plate gives slightly more depth and I can just squeeze everything in.

I haven't had a chance to really dig into any of the individual effects and get comfortable with them - having been in business travel mode since building the pedal, but it's on my to-do list for this fall to start programming using the examples provided. These are really sophisticated effects that seem similar to what I've seen of the Chase Bliss pedals - lots of shimmery echoey reverbs and weird distorted loops. I'm really excited about the possibilities!

Since I had to order 3 PCBs, and from a number of stores, I also ordered most of the parts in triplicate. I'm planning on building two more of these pedals, so I can use them for my own development and keep a few on my board with my favorite effects always loaded.
 

Attachments

  • house_sparrow_front.jpg
    house_sparrow_front.jpg
    192.2 KB · Views: 37
  • house_sparrow_guts.jpg
    house_sparrow_guts.jpg
    339.4 KB · Views: 37
Very nice build! And a great write up. I like the bird graphic on the front. I see you're using the TL074 quad op amp, I've since updated the docs and pcb to recommend a MCP6024 as a result of some noise testing, but the TL074 should do fine. If you do get any significant noise issues let me know, I'm collecting data on different builds. I seemed to get more noise on my PCBway board over my OSHpark board, but without more data it's hard to say if it was my build or the board itself.

Chase Bliss is definitely a big inspiration to both the layout of the pedal and how the software modules operate. I'm pretty sure the processor on the Daisy Seed (STM32 H7) is the same as the latest digital Chase Bliss pedals (Mood MK2, Lossy, Onward), so the processing power is there, the real challenge is in writing the DSP. Happy coding!
 
Thanks, keyth.

I have not noticed noise as a particular problem. I saw the update about the op-amp but since I'd already placed my more exotic orders and didn't feel it was a problem, I kept using the TL074. I'll include the new op-amp in my next digikey/mouser order, whenever that is - I get most parts from Tayda. The PCB was from OSHpark in my case, so maybe that made a difference.
 
Back
Top