dynacomp problem

[charly666]

Hello all im charly from argentina. this is my first post...
I have built tonepad dynacomp works of  but when turn  the sustain pot about 40% to 100%  sound turns off
voltages are

ca3080
1:0
2:3.67
3:3.66
4:0
5:0.62
6:0.99
7:8.97
8:0

         c       b        e
q1: 8.97   0.99   0.92
q2: 8:32   0.99   0.58
q3: 8.88   0        0
q4: 8.88   0        0
q5::8.98  8.88    8.44
please help !! thanks

[gritz]

Hi charly - welcome to the forum.  

The voltages around Q1 and Q2 (and at the output of the ca3080) suggest that there might be something wrong with the bias voltage Vb. With a 9volt supply Vb should be about 2.9V and so the voltage at Q2's base should be about the same (a fraction of a volt less). I would suggest starting with checking Vb and if it's low there may be an incorrect resistor, or a solder short somewhere. Perhaps the smoothing capacitor across the 27k resistor in the Vb network is faulty - is it the right way round? (a guess!).

Good luck - let us know how it goes.

[charly666]

i change the ca3080 and everything works ok now  , thanks for yor help