Spin Semiconductor

Instead use pots can I inject a voltage (between 0 and 3.3V) on the pots pin?

I am planning to use an output from a PIC in order to generate the voltage to be injected on those pins. Is it possible?

Yes

I have a similar question.

I am planning to use a PCM output from a microcontroller to drive a pot input directly. The PCM signal has an amplitude of 3.3 V and the duty cycle varies from 0% to 100%. Since there is probably a low pass filter at the FV-1 pot input it is then converted into a DC level depending on the duty cycle of the PCM signal. This saves me some external passives.

Has anybody ever tried this before and does it work?

Well, it would depend on the rate you update the PCM output and other factors but just give it a try and let us know what happens. As long as the voltage stays in the proper range it won't hurt the chip.

But, I would add the external components in any case, the chip is not tested for this use so while it may work on one batch, the process could shift and it fails to work on another. We didn't consider a raw PCM stream into the POT inputs during design.

In my opinion better to use DAC or if you have more pins from the micro controller make a simple DAC with the resistors.
I feel not much courage about something vibrating with a sound processor.

I will give it a try and post the results here

The FV-1 has heavy (100ms) filtering on the pot inputs. See the "Pot Tracking Speed" post on this forum. I assume that this filtering is most digital. I would be a little worried that putting the PWM signal directly on the input might cause unexpected results if the PWM freq and the FV-1 ADC sample rate had some beat weird frequency relationship. I would start with a simple RC on the PWM to get a basically analog signal, then let the FV-1 internal pot filtering take care of the remaining ripple.