Gravitation - Clean Signal, but engaged is Static

[motoburn]

Hi, this is my first build. Clean bypass sounds fine, but when I engage, all I get is static. None of the knobs seem to affect the static except for the mix knob. Can anyone help me with a starting point for diagnostics?

I assume I'll need to get that BTDR out of the way so you can see my solder joints, so I'll work on that in the mean time..


Thanks

 

[Robert]

I wouldn't try to remove the Belton module just yet, that'll probably result in even more problems.

I assume the lower two pots are insulated from the PCB somehow?

 

[motoburn]

I wouldn't try to remove the Belton module just yet, that'll probably result in even more problems.

I assume the lower two pots are insulated from the PCB somehow?

thanks I'll hold off trying to extract.

Yes, right now they are bent upward to form and air gap, so I know they aren't touvhing anything

 

[motoburn]

I just put power to it again and the static is gone, but not much in the way of an effect when engaged. I now have a staccato (single short) heavily clipped audible coming thru if I dig in, but silence otherwise.

 

[Mcknib]

Is R101 47K might just be the reflection but the 4th band looks orange (470K) instead of red (47K)

 

[motoburn]

Is R101 47K might just be the reflection but the 4th band looks orange (470K) instead of red (47K)

huh.. well my DMM seems to be on crack... bought in '98 at radio shack.. but it seems to be .47 M as the reading which definitely suggests you are correct. I don't know the colors, but with my eyes I could easily have grabbed the wrong one. So it looks like i need to swap that one out for the right one, yeah?

 

[Robert]

Yep, that could cause the off bias behavior you described.

 

[motoburn]

Thank you

any suggestions for replacing it around the Belton and C17?

 

[motoburn]

ok, I replaced that resistor and my initial concern has returned... idk what's going on, but now when engaged, I get clean signal but when I roll the Mix knob all I get is static

 

[Mcknib]

Do a check of your voltages

Check what voltage the regulators putting out should be 5v to pin 1 of the brick and 0v to pins 2 and 4

From your description your problem appears to be on the wet signal side

But no harm in checking all your VREF points on the schematic where you should get half power around 4.5v

 

[fig]

Is there any insulation around those pots?

 

[motoburn]

Is there any insulation around those pots?

a couple of them from Tayda had the dustcovers but the other ones didn't. for testing I have them bent upward so nothing is touching the casings.

For now, I'm waiting for some desoldering tools I ordered and am going to get the bulky items out of the way, check each of the other components values against the BOM and see if any of my soldering needs to be redone... I likely made a mistake somewhere along the way.

 

[motoburn]

Do a check of your voltages

Check what voltage the regulators putting out should be 5v to pin 1 of the brick and 0v to pins 2 and 4

From your description your problem appears to be on the wet signal side

But no harm in checking all your VREF points on the schematic where you should get half power around 4.5v

Sorry I missed this post. Thank you. I'll check these

 

[Matopotato]

Sorry for being a bit late to the party. Did you manage to resolve your issue @motoburn ? And if so what was the problem?

 

[motoburn]

Sorry, not yet. I ordered a desoldering tool, but then ended up sick for a bit then work has been chaos. I am hoping to get back to it soon. My suspicion is that I didn't do a very good job. My other two pedals (made after this one) turned out great, so I plan on checking every connection