Engineer´s Thumb - Compressor kit - not working

[Rebuilder]

Hi guys, i have here a musikding Engineering thumbs Compressor kit that is not working!

Schematic:
https://www.musikding.de/docs/musikding ... schalt.pdf

Guts Shot


Since i’m not the one who mounted the kit, i checked every component polarity etc. resolder a bunch of holes, and identified a wrong transistor in the circuit. It was with a BC337 instead of a BC327.
I changed the transistor, but its somehing else wrong.
I have bypass sound. When its on, seems like there’s no effect applied. Level pot its working , the other ones i can’t notice anything when turned, instead of one that make just a static noise in the end.
I checked every pin voltage from the ica when the pedal its on:

IC1 LM13700

1: 1,81
2: 0,82
3: 3,67
4: 3,66
5: 3,60
6: 0
7: 0
8: 4,96
9: 2,77
10: 0
11: 7,31
12: 0,55
13: 0,55
14: 0.40
15: 0,58
16: 0

IC2 TL074

1: 3,66
2: 3,66
3: 3,50
4: 7,31
5: 3,58
6: 3,57
7: 3,68
8: 2,58
9: 1,84
10: 3,49
11: 0
12: 3,37
13: 3,60
14: 4,47

Transistor BC327

C: 1,81
B: 2,58
E: 1,84

The unique thing that i doesnt verify was the diodes values…since theyre small and soldered. Other thing that i noticed its that the diode leds on the board doesn’t show any light signals changing with the sound…

What am i missing here? Any help?

[jimilee]

On your in wire, is there a stray wire touching the ground solder joint? I wouldn’t worry about the diodes just yet.

[Rebuilder]

On your in wire, is there a stray wire touching the ground solder joint? I wouldn’t worry about the diodes just yet.

Nice Eye, definetly a stray of wire there but not making contact. But was a matter of time until it does. So i cut that off.

After a lot of testing and debugging i noticed that when i start rotating the Ratio POT i can ear a transition from clean sound to a distorted sound sound with a lot of crunchy noises. unless i have this pot all down, the sound of the pedal its not clear.

Any idea what can me causing that?
The other pots, i doesn-t notice any variation of sound when i turn them up or down. its all the same sound to me...unless the volume one...

[hueljannie]

The solder junction between your in wire and the ground should be clean and free of any stray wires. Do not be concerned about the diodes at this time.

[Adima78]

Hi,
Did you solve your issue ?
I have just finished mine and I have no sound, the switch diode is well powered, but nothing...
I have checked all the soldered points, and everything seems to be Ok.
Do you have any clue to troubleshot the issue ?
Thanks

[Adima78]

In fact I have the same problem than you, but the bypass doesn't work, I hear a big big noise when the switch is off, and when is on no more noisy hum but nothing come from the instrument...

[Rebuilder]

In fact I have the same problem than you, but the bypass doesn't work, I hear a big big noise when the switch is off, and when is on no more noisy hum but nothing come from the instrument...

Sorry i was without notifications and only today i realized your questions here. You still need some help?