I changed Q1 but that was not the issue
Did the sound return when Q1 was disconnected?
I see that R56 and R57 changed color a little.
This means you have a short circuit somewhere. Are they getting hot?
A little burned the resistance is correct and they are just for power right? But that cannot be an issue?
You can check their value with your ohmmeter (in circuit).
Do you think it might be transistor or capacitor?
Not a capacitor. Neither a transistor if you got the DC voltages right in the picture here.
Hi Jean Pierre
I did some more digging. on ratios 2-20 the output does not change. as soon as the comp is in slam the output gets very loud, i think this is the volume it should be. And when I tap C9 quite hard I see changes in the volume. I swapped C9 out but no changes.
Work on Q1 did not change anything, with our without.
R56 and R57 are not hot or warm. same temp as all other components (excluding the walls of SK25, they are light warm as they should be i guess)
R56 has 6.6 Ohm and R57 has 7.6 Ohm
I checked the AC and DC Voltages all measured to 0V with 1VAC and XLR pin 2-3:
AC level on TP3: (measured first with 100mVAC on the input and it was around 1/10 of the now measured voltages)
- Ratio 2 : 25mVAC
- Ratio 4 : 50mVAC
- Ratio 8 : 80mVAC
- Ratio 12 : 133mVAC
- Ratio 20 : 230mVAC
- Ratio SLAM : 12.74 VAC
DC level on TP4: all on point
DC level on JMP1 pin 1:
- Ratio 2 : -0.2 to 1.7 mVDC
- Ratio 4 : -17.8mVDC
- Ratio 8 : -19.7mVDC
- Ratio 12 : -21.2mVDC
- Ratio 20 : -25.2mVDC
- Ratio SLAM : 2.79 VDC
TP6 6mVDC
TP5 on point
A 13,22VDC (crackle while placing the probe)
B -0.55VDC
C 13.8VDC
D -1.35VDC
E 15.6VDC
F -0.75VDC
G -15.9VDC
Thanks a lot for helping me
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