On Thu, 1 Nov 2018 at 16:24, Vadim Zavalishin <
vadim.zavalis...@native-instruments.de> wrote:

> On 31-Oct-18 18:19, Stefan Stenzel wrote:
> > Vadim,
> >
> > I was more refering to the analog multimode filter based on the moog
> cascade I did some years ago, and found it amusing to find a warning
> against it.
> Ah, you mean the one at the beginning of Section 5.5? Well, that's an
> artifact of the older revision 1, where the ladder filter was introduced
> before the SVF (I still believe it's better didactically, unfortunately
> new material dependencies made me switch the order). The modal mixtures
> of the transistor ladder are asymmetric (HP is not symmetric to LP and
> has the resonance peak kind of "in the middle of its slope" and BP is
> not symmetric on its own). I felt that it might be confusing for a
> beginner if their first encounter with resonating HP and BP is with this
> kind of special-looking filters, hence the warning. With revision 2 this
> warning becomes less important, since the 2-pole LP and BP were
> discussed already before, but I still believe it's informative. After
> all, it doesn't say that these filters are bad, it says that they are
> special ;)
If you prize symmetry then you can use a cascade with 2 x one pole HP and 2
x one pole LP to make a 4 pole BP (band pass) then you can use the same old
FIR based output tap mixing to generate all the different responses. It may
not be so easy to do in a real circuit, but in software we're not bound by
what is easy to build :)


> > Anyway, excellent writeup,
> Thank you! I'm glad my book is appreciated not only by newbies, but also
> by the industry experts.
> > I wish I cuold have it printed as a proper book for more relaxed reading.
> Hmmm, 500 A4 pages would be rather heavy ;)
> Vadim
Stefan: This sounds like the prefect excuse to get a HiDPI tablet to store
and read all your PDFs, much lighter actual books and easier to search :)

I've gone paper free now and write notes in PDF format and annotate
directly on published papers in PDF format, which is great since it's
easier to find things and it's all backed up. I lost a paper notebook and
was always losing conference papers I printed out and annotated, which is
quite frustrating. Digital has it's own challenges, but overall I'm happy
with the move and love that everything is backed.


dupswapdrop: music-dsp mailing list

Reply via email to