[sdiy] VA vs. RA: Square wave

[Amos]

Hello all,

I have noticed in some analogue oscillators squarewave output, that
there is an unchanging time constant governing the loss of voltage
from the "high" state of the oscillator, such that at low frequencies
you actually see a gentle ramp downward in voltage from the start of
the cycle until the next reset, instead of a perfect square.  Since
this ramp downwards is not frequency-dependent (or not so much), at
high frequencies the same oscillator puts out a more perfect square
wave.

Is this subtlety simulated in any virtual analogues, or do they tend
to output a perfect square wave the same shape at all frequencies?  I
am sure it would make a timbral difference.

Cheers,

Amos