Low Tide - No Effect

[dontstaylong]

Hi all,

I've been building two Low Tide pedals, and completed one (and so far, love it!). The second one has been giving me trouble, and I'm having a hard time figuring out where to go next with it.

Currently getting clean signal through it and the level knob works, but when I dial the mix to 100% it almost entirely cuts out (very faint signal still comes through). I'm also not hearing the effect take place, though I haven't set the trimpots yet.

I've got a multimeter and, admittedly, have no idea what to do with it as I'm pretty new to all this. How should I go about testing? I don't see any shorts, though I may go back through and reflow each of the pots' connections.

 

[fig]

I’d make sure that LM13700 is seated well..likely not the problem though. Hopefully just some trimmer twisting.

 

[dontstaylong]

I’d make sure that LM13700 is seated well..likely not the problem though. Hopefully just some trimmer twisting.

Hi! Realized I never responded to this. I reseated the IC and it's still behaving the same way. When the mix is 100%, there's no audio at all and the various knobs do nothing otherwise, which leads me to think there's either a short or something disconnected.

How should I go about testing to see where things are breaking down? I'm pretty new to all of this (I know, this pedal is probably biting off more than I can chew).

 

[PJS]

First thing is going to be to make sure that the BBD bias is set correctly. You can't guarantee to get any wet signal without doing that.

 

[dontstaylong]

First thing is going to be to make sure that the BBD bias is set correctly. You can't guarantee to get any wet signal without doing that.

The issue is that using these instructions to set up the BBD, I'm getting almost zero signal when the Mix pot is at 100%. IE - when I'm only hearing signal that's going through the effect, there's no signal actually getting through. Nothing is even making it to the trim pots.

When trying to get the pots into place, I heard a slight crack from the PCB in the dual gang potentiometer, making me wonder if that's the culprit.

I'm getting some inconsistency with the input jacks, so I'm going to reflow those and see if it helps

 

[dontstaylong]

Six months later, finally found time to poke at this thing again.

The issue I was having before was that clean signal was coming through, but with Mix at 100%, nothing was making it through the circuit. I've reflowed everything and the solder joints look good. Glad I posted about this previously - I'm gonna assume that I broke one of the dual gang pots getting it onto the PCB.

I've got a multimeter (this guy) but, frankly, I have no clue how to use it. I know this is some real baby's first steps stuff, but what settings do I need to use and what should I be measuring to see if the pot is busted?

 

[delayed]

If you have a working one you can compare the volts. Have you swapped the BBD ic? The text font looks a little different.

 

[dontstaylong]

If you have a working one you can compare the volts. Have you swapped the BBD ic? The text font looks a little different.

It's the same one that's in the pedal I have that's working, it's an MN3207 which I believe is supposed to work as well? I'd ordered this when I couldn't find any V3207Ds. I could try reordering the correct chip, seems like they're easier to find now?

 

[delayed]

I was saying a good first step would be swapping the ICs between the two pedals to confirm they both work. There are plenty of fakes for the BBD ics and some could just be dead on arrival. Are you saying it is the same physical Ic or you got them from the same place?