ADHD Troubleshooting

[Uberschall]

Hi all -

I am building the ADHD, and I am getting signal but it's not boosted/effected at all. The buffered bypass works, LED turns on and off correctly.

I think this circuit is cursed for me, I've tried building the Aion version twice with poor results.

I'm getting 9.13v in from my OneSpot

IC Voltages
1: 4.35v
2: 4.33v
3: 3.89v
4: 0.6mv
5: 4.34 v
6: 4.35v
7: 4.35v
8: 8.72v

2N7000 on left of PCB
S: 4.35v
G: 45mv
D: 4.34

2N7000 on right of PCB
S: 53mv
G: 94mv
D: 0.14mv

2N5457 on left of PCB
D: 1v
S 7.7v
G: 0v

2N5457 in middle of PCB
D: 7.71v
S: 0.99v
G: 0.6mV

2SC1815
E: 3v
C: 5.67v
B: 3.5v

 

[Uberschall]

Bump.... any ideas?

 

[Chuck D. Bones]

Hi all -

I am building the ADHD, and I am getting signal but it's not boosted/effected at all. The buffered bypass works, LED turns on and off correctly.

I think this circuit is cursed for me, I've tried building the Aion version twice with poor results.

I'm getting 9.13v in from my OneSpot

IC Voltages All IC1 DC voltages are ok
1: 4.35v
2: 4.33v
3: 3.89v
4: 0.6mv
5: 4.34 v
6: 4.35v
7: 4.35v
8: 8.72v

2N7000 on left of PCB
S: 4.35v
G: 45mv should be same as D
D: 4.34

2N7000 on right of PCB should all be same as Vref
S: 53mv
G: 94mv
D: 0.14mv

2N5457 on left of PCB
D: 1v
S 7.7v
G: 0v

2N5457 in middle of PCB
D: 7.71v
S: 0.99v
G: 0.6mV

2SC1815
E: 3v
C: 5.67v
B: 3.5v

BOM calls for TL082, you installed 1458. What other parts did you sub?
Both 2N7000's have bad connections. Either loose in the sockets or bad solder joints.
Both 2N5457s have very low Vp which is throwing their bias off. They are in-spec, but should be selected for Vp around 2 or 3V for best performance. This is not causing the problem you describe.
Your pictures are not good enough for us to perform visual inspection.
Clean the board, remove all flux residue. Inspect all solder joints and component values.
Make sure the TONE pot body is not contacting the board.
Show us how the stomp switch is wired.
Think about what is common between all three OCDs you have built.

 

[Uberschall]

Thanks, I'll clean it up and take better photos.

The chip was the only sub, and I have tried with a TL082 and had the same results.

I've checked all the component values, but will do so again when I clean up the board.

As for the commonality between the OCDs... the Aion ones were built a few years ago, so I don't really know what would be in common.