Please help:
V+ = 15.3V
V- = 15.2V
B+ = 46.3V
Initial conditions:
IN pot @ max
OUT pot @ min
REC pot @ max
Bypass toggle @IN
All Push buttons @UP
Input signal: Sinus 1kHz, 1VAC
Jumper JMP1: removed
Results:
TP1 to 0V = 30,9VDC
TP2 to 0V = 31.0VDC
TP1 to TP2 = 3.0VAC
TP3 to TP4 = 0 VAC
TP3 to 0V = 0VDC
TP4 to 0V = 0VDC
Output = 4.6VAC when pot P2 is at min and 25.6VAC when pot P2 is at max.
Without front PCB
TP1 to 0V= 30.9VDC
TP2 to 0V=30.9VDC
TP1 to TP2 = 3.1VAC
TP3 toTP4 = 0VAC
Without IC's and front PCB
TP1 toTP2 =4,6VAC
TP3 to TP4 =0 VAC
TP3 to 0V =3.1VAC
Changed conditions:
Jumper JMP1: on 1-2
Input signal: Sinus 1kHz, 0.3VAC
OUT pot @ max
Results:
TP3: 0.VAC (black probe on 0V)
TP4: 4.8VAC
TP5: 4.3VAC
TP6: -6.03VDC
Output: 10.1VAC
The usual suspects look OK.
The input transformer label is facing to the back and the Torx screws are on the correct spot upwards.
Values on R1, R2 and P1 ,P2, P3 are correct. R1, R2, are not touching transformer pins. C12 doesn't touch the tube or transformer.
When I remove the input signal, the voltage drops to 0
