Help troubleshooting Triple Chorus

[foogy]

Hi,

I have completed the assembly of my Triple Chorus... without much surprise I didn't get it right on the first try

The symptoms are as following:

Mix output: something that sound close to the input sound. Basically, I'm not hearing any kind of modulation.
Output 1: weak output
Output 2: very weak output
Output 3: strong ouput
Waveform knobs: does absolutely nothing.

What I have tried so far:

swapping around the TDA and 4011 IC without noticeable difference in the result outputs.

Some questions:
Is the mixed output supposed to have the effect full on regardless of the Mode Switch position?

Any advice on how to troubleshoot this, things to look for or hints appreciated.

Thanks!