ping reverb

[jazzmaster]

Hi
I built this pedal and found some values of voltage that should not be according to the instructions page,
I have at the output of the chip a voltage of 0.5 volts, in R12 and R13 .
When specified that there should be zero,
All other values are correct.
For the avoidance of doubt the pedal works.
Just the signal is not clean.
Has anyone encountered a similar problem?