I need help debuggin a Big Muff Pi

[DeusM]

Hey guys. I made a BMP and it doesn't work. It's the second time. I probed it with an audio probe and I can hear sound from the beginning of the circuit but when the guitar is plugged the volume is too low. Basically I respected the circuit. I added a prescense control in R19 like described in AMZ. I added a switch to activate it or jump staring to earth at that point to remove mid scoop. Triple checked connections twice. Here are the measurements:

Q1
C = 8.75
B = 1.45
E = 1.13

Q2
C= 3.95
B= 0.65
E= 0.05

Q3
C = 4.29
B = 0.60
E = 0.03

Q4
C=7.61
B= 8.2
E= 7.59

D1
A = 3.64
K = 3.96

D2
A = 3.96
K = 3.64

D3
A = 4.29
K = 4.00

D4
A = 4.00
K = 4.29

D5
A = 0
K = 9.09

Schematic


I used PN222A in Q1 Q3 Q4 and MP2A18 in Q3

I took some pictures of the pcb but they look bad.

I hope you can give me a hand guys. Thanks!

[EBK]

You've double-triple checked the connections.  Have you rechecked the component values?  At least Q4 looks misbiased.  (I don't really know offhand what the voltages should be though).

[DeusM]

You've double-triple checked the connections.  Have you rechecked the component values?  At least Q4 looks misbiased.  (I don't really know offhand what the voltages should be though).

Not of all the components. I was very careful when I placed them but I'm going to doble check them again.
When I probed from Colector of Q4 it sounded loud and clear but I'll check the emisor resistance.

[DeusM]

Ok. So I had one resistor wrong. Now there is sound but not distortion. I'll keep checking resistors,

[DeusM]

Rechecked componen values. They seem fine. Could it be that I still dindt put the LED? Can it afffect the circuit? I'm going to check the new values in the trantistors

[DeusM]

Now it reads:

Q1
C = 8.75
B = 1.45
E = 1.32

Q2
C= 3.95
B= 0.65
E= 0.05

Q3
C = 4.29
B = 0.60
E = 0.03

Q4
C= 5.96
B= 1.57
E= 1.09

[EBK]

Now I'm looking at Q1.  That collector voltage looks high to me (again, without knowing what it should be in this circuit).

[DeusM]

Working! There was a pad lifted at Q1 emiter. Is was imposible to see but there was no continuity. Thanks for your help EBK! Your always there when I need it. I'm going to rock now.

[EBK]

Happy to help!  Glad it's working.