Leprechaun/EQD Rainbow Machine problem

[ch ra]

Hello, I've been building pedals for a few years now but I am new to this forum. I built up the Leprechaun and ran it through my testing rig. Right now, I get only clean sound when the circuit is hooked up. Since the schematic isn't up yet, I'm stumped about how to troubleshoot this but I'm wondering if any of you have any ideas. As you'll see from the photo below, I ran out of 1uF MLCCs and used a few box capacitors as substitutions, but I can't imagine that would be a problem. Also, I've not hooked up the switches or expression jack (though I added a jumper for the jack as seen below), I am just running in and out directly and do not have the magic switch hooked up--could that be it? I don't believe the pot connections are the problem--when the photo was taken I did light connections so that I could re-adjust them when I box the pedal, but since them I've made all of the joints for the pots clean and solid.

I'd appreciate any advice or info (e.g., voltages) that you might be able to provide. Thanks!

 

[Robusto]

Does anything ever work on the first try?
I’ve been through the obvious stuff.

Trying to audio probe. Difficult to follow the signal chain with no schematic.

You expect it to not work?

Visual inspection: Solder joints, debris, part values, orientation. Take your time, lotta magnification and good light. Most problems are found this way and it's usually the quickest.

 

[thedwest]

Does anything ever work on the first try?
I’ve been through the obvious stuff.

Trying to audio probe. Difficult to follow the signal chain with no schematic.

I'm sure its one of the obvious things but did you check IC4? I had a bad one and only got a clean signal when I turned it on. After swapping it out, it works perfect and sounds exactly like the demos of the original.

 

[Robusto]

I'm sure its one of the obvious things but did you check IC4? I had a bad one and only got a clean signal when I turned it on. After swapping it out, it works perfect and sounds exactly like the demos of the original.

Just swapped it. Same.

Soooooooooo....is there a schematic for this project?

 

[phi1]

I agree it would be a pain to troubleshoot without a schematic... fortunately I haven’t had to yet.

There is a fair bit of troubleshooting you can do without one though. Does it pass signal in bypass? Do the positions of any knobs make a difference? With the probe can you get signal from the pcb input to the fv-1 input pins? Can you inject signal on the fv-1 output (maybe try a couple components downstream for safety) and does it reach the output?

I agree a schematic would be very helpful for you, hopefully it’s available soon, just offering some ideas in the meantime.

 

[Robusto]

I am able to probe the fv-1 and get affected signal, which changes when I turn some of the knobs. I just don't know where the signal is getting hung up from there without a schematic.

 

[Robert]

I just don't know where the signal is getting hung up from there without a schematic.

I'll try to get the schematic ready for you this afternoon.

 

[Robusto]

I'll try to get the schematic ready for you this afternoon.

Any luck yet?