Help reading schematic

[sndansby]

I am trying to trouble shoot the Leprechaun pedal that I built and I have built an audio probe but I do not know how to follow the signal path. Is there a tutorial on how to do this somewhere?

Thanks

 

[fig]

You have the schematic? I don't see it listed.

 

[sndansby]

This is the schematic https://forum.pedalpcb.com/attachments/pedalpcb-leprechaun-jpg.3801/

 

[fig]

Good Grief that's a roadmap. Someone else could likely do it faster and more accurately than I.

If not, I'll do whatever I can to help you with it. This probably isn't a "get your feet wet" signal path, but then again..if you want to learn to swim...jump in!

 

[PJS]

Important touch points are going to be input > IC1 pin 3 > IC1 pin 1 > IC2 pin 1 > IC2 pin 28 > IC2 pin 2 > IC2 pin 27 > IC3 pin 2 > IC1 pins 5, 6, 7

 

[giovanni]

What are the symptoms? Can you post pics?

 

[sndansby]

The first is the enclosure that I etched.

 

[sndansby]

The leds will light up and I can get audio with the probe at some points.

 

[sndansby]

Important touch points are going to be input > IC1 pin 3 > IC1 pin 1 > IC2 pin 1 > IC2 pin 28 > IC2 pin 2 > IC2 pin 27 > IC3 pin 2 > IC1 pins 5, 6, 7

The ICs are getting signal at the points. Except for the IC4 and IC6.

 

[sndansby]

I am not getting signal from the Spectrum or the Dispersion pots.

 

[sndansby]

I am noticing some of the caps that I used are the 1uF 50V Radial Tantalum Capacitor and some of these seem to be only receiving signal on one side like they are grounded but I do not see this in the schematic. C9, C11, C13, C15, C16 etc. These are polarized caps but I read something that said they would be good in this application. Could this be the problem?

 

[Robert]

If you used polarized caps for the 1uF coupling caps you have to ensure they are oriented correctly, some (most/all) of those caps have a DC bias on them.

 

[sndansby]

So changing these out would be a good place to start?

 

[sndansby]

I changed out all of the 1u caps. The ones that I had were a large so it doesn't look pretty but those function better. I am still having the issue where I am not getting any other output. I am not getting output from the D100 but I assume that is because it is on the power side of the schematic. Is this correct?

 

[PJS]

So, to confirm, IC 2 pin 7 has signal? If that is the case then R8 and C4 are the only components on the board from there to the output, and then there would only be the footswitch to the output jack