Steffenvy the result has random noise
To reflect specifically on this...
This is caused by the fact that the oscillator node's output is band-limited (or anti-aliased) for the sawtooth wave (and triangle and square), which causes the signal to swipe through the shaping curve not in a perfect linear fashion, but with some "shaking" going on near the edges -- if that makes sense the way I'm describing it.
A quick and easy fix is using one or more lowpass filter nodes to try to attenuate the noise in the higher frequencies, like this:

Note that I'm also using a highpass filter here to remove the DC offset.
Another, slightly more complex alternative is using the Timer Node to construct a mathematically accurate sawtooth-like wave.