Noisy Pauper

ericrudd

ericrudd

Member
Finished up my first build today. A Pauper pedal. The good news is, the LED light up. The bad news, there is a bad ground hum in both foot switch positions. Uggghh. Where to start troubleshooting?
Any help appreciated.
 
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Tried a different chip (I bought a few). Pin 3 measured 2.22 on that one. In looking at the schematic, if I’m reading it directly Pin 3 is where the input shows up. Maybe I should work backwards from there (if that value is indeed wrong).
 
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ericrudd said:
Tried a different chip (I bought a few). Pin 3 measured 2.22 on that one. In looking at the schematic, if I’m reading it directly Pin 3 is where the input shows up. Maybe I should work backwards from there (if that value is indeed wrong).
Click to expand...
I studied your resistor values, I believe they are all correct.
Cleaning the Board might remove some crud that could be causing a short or show a dry solder joint
I'm also concerned at the size of solder build up on the underside of the Footswitch pads , Make sure there not touching!
 
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Barry said:
Some of those solder joints look like they could use a reflow, I see a few that look like round blobs they should look like a Hershey kiss or a teepee
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I’m still trying to get better at soldering. The stupid stuff tends to pull up toward iron instead of staying in the holes!!
 
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phi1 said:
All those voltages look good except I would expect pin3 to also be close to 4.5v (though I could be wrong). If it’s wrong I’m not sure shat could be causing that. I *think* your switch-diode connections make sense, without having thought too much about it
Click to expand...
The voltages are all good.
Eric's DVM is loading down the voltage when he measures pin 3. You're using a cheap DVM. It's ok in this case, we can compensate for it, but if you get serious about pedal building, get one that has 10Meg input impedance. Yours is 1Meg.
 
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It’s a Tiswall 65watt iron. RJ969. I have Kester solder Sn60Pb40 solder, although I ended up not using much of it because it’s 1.27mm and I felt like it was a bit big for the connections. I ended up using the solder that came with the iron because it was a smaller diameter. How’s that for scary? I have no idea what that is because it’s not labeled.

{insert photo of forum members shaking their heads in disgust here}
 
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Disconnected and resoldered all the jacks, foot switch, etc. Tried it again (without mounting in enclosure) and got the same behavior....plenty of volume, tone control works. With Drive all the way up there is no noticeable increase in overdrive, three way switch doesn’t do anything, nor do the dip switches.
 
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Weird that neither switch does anything...

Where did you get your MA856 diodes? Does your meter have a diode setting? Can you confirm that they measure around 0.5-0.7v across each one from anode to cathode?
 
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phi1 said:
Weird that neither switch does anything...

Where did you get your MA856 diodes? Does your meter have a diode setting? Can you confirm that they measure around 0.5-0.7v across each one from anode to cathode?
Click to expand...
I got them here....https://www.pedalhackerelectronics.com/Original-Panasonic-MA856-Diode-p/ma856.htm

I’ll check the voltages a bit later.
 
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ericrudd said:
Probably worth confirming a couple things....this is the toggle switch I got...

stompboxparts.com

DPDT Toggle Switch ON/OFF/ON- Solder Lug- Long Bat

Top Quality Parts for Guitar Effects Pedals and DIY Music Devices. Knobs, Pots, Switches, LEDs, Enclosures, Jacks, Wire, Resistors, Capacitors, Semiconductors
stompboxparts.com stompboxparts.com
Click to expand...
With the switch in the UP position, the Center & Bottom lug should be making contact, Check for Continuity!
In the Down position, Center & Top Lug should be making contact, Check for Continuity!

When soldering any Switch, Pot, Trimmer, Transistor ect, Always allow to Cool each time you solder a Pad.
With Switches, Always solder one pad, Cool, Skip one, Solder, Cool, Skip one,
A Minimum of 20 seconds between each pad!
When you get efficient at Soldering a Pad in 2 seconds, this may vary!!!
 
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