[sdiy] D50 a VA or not?

[Scott Nordlund]

> --- Den mån 2010-12-27 skrev Scott Nordlund :
>
> > Från: Scott Nordlund 
> > Ämne: Re: [sdiy] D50 a VA or not?
> > Till:
> > Kopia: synth-diy at dropmix.xs4all.nl
> > Datum: måndag 27 december 2010 22:01
> >
> > > This sounds like synthesis of pulse waves using BLEPs,
> > give or take. If so, the D50 probably predate the papers on
> > the idea?
> > >
> > > T.
> >
> > That's exactly what I was thinking.
>
> Whats BLEP's?
> High frequency bandlimited steps or something?

Right, also related is BLIT (band limited impulse train).  You
just use a table with a band limited transition in place of the
non-band limited discontinuities of a square or sawtooth wave.
They're frequently used for VA type synthesis.

So if you just use instead a "resonant BLEP", maybe sampled
from an actual analog filter (or a number of samples taken at
different resonance settings), it can be scaled to simulate a
changing cutoff frequency.

Of course there are numerous other details, but if Roland 
actually did this, they probably just used the simplest
possible implementation.