Phase II issues

Ale_jellybelly

Ale_jellybelly

Well-known member
1. The yellow led doesn't light up in a smooth sine wave but the rise time is very fast, I can only control the fall time with the pots and trims
2. The led stalls when the rate is very slow, it stays on

What could it be?
Pics (I know, I need to remove some flux)
PXL_20260726_173833295.jpg PXL_20260726_173936928.jpg PXL_20260726_173949189.jpg PXL_20260726_173957201.jpg
 
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Ale_jellybelly said:
1. The yellow led doesn't light up in a smooth sine wave but the rise time is very fast, I can only control the fall time with the pots and trims
2. The led stalls when the rate is very slow, it stays on

What could it be?
Pics (I know, I need to remove some flux)
View attachment 121552View attachment 121553View attachment 121554View attachment 121555
Click to expand...
Looking at your pictures, could it be some solder residues shorting a soldering pad with another pad or with a nearby pcb trace ?

You can try to clean the board by vigorously brushing the pcb's soldering side with a dry toothbrush until you cleared most of of the soldering residues.
You can also clean the little spaces between pads, using the tip of your soldering iron. Move quickly to avoid overheating the pcb.

The best for residues would be some pcb cleaner spray, i use something with a brush on the tip and it's very effective to clean pcbs. To be used outside the house and maybe with a protection mask on, because it's full of chemicals.
1785098046165.jpeg
in red, some solder residue examples.
In blue, a possible short.
The right pad looks like there's a bit too much solder and it could be touching the next pad on the left.
 
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eh là bas ma said:
Looking at your pictures, could it be some solder residues shorting a soldering pad with another pad or with a nearby pcb trace ?

You can try to clean the board by vigorously brushing the pcb's soldering side with a dry toothbrush until you cleared most of of the soldering residues.
You can also clean the little spaces between pads, using the tip of your soldering iron. Move quickly to avoid overheating the pcb.

The best for residues would be some pcb cleaner spray, i use something with a brush on the tip and it's very effective to clean pcbs. To be used outside the house and maybe with a protection mask on, because it's full of chemicals.
View attachment 121570
in red, some solder residue examples.
In blue, a possible short.
The right pad looks like there's a bit too much solder and it could be touching the next pad on the left.
Click to expand...
Thanks for taking a look
What might seem solder residue is actually just dried flux
I just gave the board a good scrub with some contact cleaner, and checked the point in the blue circle, no contact there
I found a thread blaming the LFO opamp for the wave shape(https://forum.pedalpcb.com/threads/phase-ii-lfo-wave-shape.25165/ ) . I'll try swapping it as soon as the board is dry
 
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Measurements taken with DEPTH at max and RATE, FEEDBACK and trimmers around halfway

IC1:
1: 0
2: 0
3: 0
4: -8,74
5: 0
6: 0
7: 0
8: 9,19

IC2:
1: 0
2: 0
3: 0
4: -8,74
5: 0
6: 0
7: 0
8: 9,19

IC3:
1: 0
2: 0
3: 0
4: -8,74
5: 0
6: 0
7: 0
8: 9,19

IC4:
1: 0
2: 0
3: 0
4: -8,74
5: 0
6: 0
7: 0
8: 9,19

IC5:
1: fluctuates between 2-ish and 8-ish
2: fluctuates between 0 and 0.5
3: fluctuates between 0 and 0.5
4: -8,74
5: 0
6: 0
7: 0
8: 9,19

IC6:
1: stays around 8-ish, then dips briefly between 2 and 3, then goes up again
2: fluctuates between 0 and 0.5
3: fluctuates between 5,9 and -1,5
4: -8,74
5: 0
6: 0,72
7: fluctuates between 4,5 and -4,5
8: 8,55

IC7:
1: 9,19
2: 5,28
3: 0
4: -3,68
5: -8,74
6: 4,23
7: 5,69
8: 9,19
 
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Ale_jellybelly said:
2. The led stalls when the rate is very slow, it stays on
Click to expand...
same thing on mine.
Ale_jellybelly said:
IC1:
1: 0
2: 0
3: 0
4: -8,74
5: 0
6: 0
7: 0
8: 9,19
Click to expand...
i get approximately the same readings on my build at IC1 TL72. I just have a steady -7.98V at pin4, with 9.1V at pin8 and 9.42V at the DC jack, but i guess that's probably nothing.

Same readings at IC7 TC1044 and at IC6 too except pin3 and pin7 are fluctuating with similar values from +4 to -4V i'd say.
I didnt check all ICs, it looks like yours are fine. I can check somewhere else if needed.

Only difference is that my led is lighting up more smoothly than yours.

Have you tried with another led ?
Do you have a phasing effect on the signal ?
 
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eh là bas ma said:
same thing on mine.

i get approximately the same readings on my build at IC1 TL72. I just have a steady -7.98V at pin4, with 9.1V at pin8 and 9.42V at the DC jack, but i guess that's probably nothing.

Same readings at IC7 TC1044 and at IC6 too except pin3 and pin7 are fluctuating with similar values from +4 to -4V i'd say.
I didnt check all ICs, it looks like yours are fine. I can check somewhere else if needed.

Only difference is that my led is lighting up more smoothly than yours.

Have you tried with another led ?
Do you have a phasing effect on the signal ?
Click to expand...
Phasing is there so the effect is working
I haven't tried with another led, first I'll try changing the LFO IC
 
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