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Zero Point Mini Muffed

Started by felipesareas, December 07, 2020, 10:32:25 AM

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felipesareas

Hi Guys, It's been a long time since I put my pedal builds on hold. Recently I resumed and finished successfully many madbean pedals. However,  I'm not being able to make my Zero Point Mini work. ICs and voltage regulator are reading the same value as listed by here in another post by Madbean.  It's not like the pedal is not working at all. The time pot makes that usual glitchy sound it does make normally when rotated while sound is coming through and I get very few muddy repeats when all setings are at max but when I lower the feedback I get no repeats at all. Rate potentiometer the switches mod and ring don't affect the sound at all.

I soldered pins 3 and 4 of PT2399 together as suggested here at the forum and nothing changed either. I checked all eletrolytic and the one tantalum capacitor orientation and all is right. Also swapped the PT2399 with the one in my sparklehorn which was working perfectly and got the same sound

I also checked that all potentiometers are placed correctly with the correct corresponding values and also checked that my PCB hasn't got the issue that some were reported to have concerning the pin 7 and 8 unintentional connection due to PCB manufacturing problem

Any idea about what might be going on? I don't know what else to try.

Thanks a lot, Felipe

felipesareas

BTW the voltages measured are

IC1:
1: 4 VDC
2: 4 VDC
3: 4 VDC
4: 0
5: 4 VDC
6: 4 VDC
7: 4 VDC
8: 8 VDC

IC2:
1: 5.1
2: 2.5
3: 0
4: 0.1
5: 2.9
6: 2.5
7: 0.6
8: 0.6
9: 2.5
10: 2.5
11: 2.5
12: 2.5
13: 2.5
14: 2.5
15: 2.5
16: 2.5

IC3:
1: oscilating
2: 4
3: oscilating
4: 0
5: 4
6: 4
7: oscilating
8: 8

regulator:
8
0
5

madbean

#2
All the voltages look good. Maybe slightly low on the supply side @8v but that's not a big deal. Everything you listed follows and checks out.

- actually with the 1n5817 and 47r resistor both in line on the power 8v is maybe not surprising. I have no idea where my build is so I can't easily compare.

Maybe a pic of the board.

felipesareas

Thanks a lot for the reply Brian! I'll check resistors and capacitors. I'm attaching two pics of it. I tested it before boxing it but when I got the muffed sound I just thought that I was setting it in a bad way rather than it not working properly

felipesareas

Just found it. I got not one but four mylar capacitors wrong (10x higher value). I remember this was the first Madbean PCB that I soldered (in 2014) By that time I wasn't used to reading faradays so I mistook decimals. Weird because That's one of 15 pedals from madbean and the only one in which I made such mistake.

Thanks a lot for the support!!