I have three 1222 modules with AS3340 and each suffers from a very limited pulse width range (see osc images)
The voltage on pin 5 of TL072 ranges between 0V and 0.87V (the PWM pot fully open at 0Ohms) although I would expect 4V at the upper end.
I went through all troubleshooting advices, applied all suggested changes but wthout any finding or effect.
I also built the stripboard variant which provides full pulse width range with 0-4V at pin5.
I had a look at the schematics and obviously 1222 quite some different resistors for PWM than the stripboard version. Is this a known design issue?
I would be happy to get any suggestion to fix this.
