Ah - that's even better.

Thanks. I now have the following and it is working now.

Why isn't the patch below inverting the input signal?

Is there a simple way to give a single pulse to startup the patch instead of the workaround in the red circle?

Thanks! Yes the loop is working now.

Is such a feedback loop as below forbidden in Pure Data? Can't get it to work...

Now we are getting somewhere:

I'm trying to make a mathematical integrator module (not a slew limiter), and indeed feeding a square wave should result in a triangle wave at the output. But sadly for some reason it's not working...

Thank you! Yes that should work, but strangely I'm not getting the results that I think I should get...

Found out just now that the feedback of y by using [send] + [receive] to get y[n] = x[n]/samplerate + y[n-1] results in a drift of y that ultimately drowns the signal.