MOTM

In a message dated 3/2/02 3:30:49 PM Eastern Standard Time, mbedtom@... 
writes:
Tom Farrand writes:

>>Specifically, what are typical characteristics of a fixed filter bank 
 section?  I admit that I thought a FFB was merely an early graphic equalizer 
 but others seem to indicate they are not.  How do FFBs sections differ from 
a 
 conventional graphic equalizer section?  What sort of "Q" do such filters 
 use?  A Moog 907A employs 8 band controls with a low-pass and a highpass 
 section.  Do the low/high-pass knobs adjust the cutoff frequency of the 
 filter networks or the processed/unprocessed mix?<<

An EQ adds peaks or notches at different frequencies to a sound.  You 
typically only get about 12db of cut or boost.  A fixed filter bank has a 
bunch of bandpass filters arranged in parallel.  If they are all turned down 
you get no sound.  If you turn one band up, you only get sound filtered 
through that band.  As someone else mentioned, you can get much more extreme 
changes to a sound with a filter bank because of this.  And just as you can 
arrange a number of bandpass filters in parallel, you can also include a 
lowpass and highpass in there too to do the same thing.

>>What is a "super-saw"?  If I were to see one on an oscilloscope, what would 
I 
see?  Sound-wise, is there much similarity between a "super-saw" and 
hard-sync (of saw-VCOs)?<<

It's something from the Roland JP-8000/8080 virtual analog synths.  It sounds 
like 7 buzzy sounding detuned sawtooth oscillators.  There is control over 
how much to detune them.  I would imagine visually it looks like 7 detuned 
sawtooths, but that is something I will have to look at some day.  No, it 
doesn't sound like hard-sync.  It is good for helping one get a similar sound 
to old string synthesizers such as those from Crumar or Arp.

-Elhardt