Okay, here's the story (I've got the schematic right in front of me):
The Moog 907 Fixed Filter Bank had ten controls. The first knob was a
shelving filter marked "Low Pass" and the last "High Pass." In between, the
resonant frequencies of the bandpass filters were labeled: 250Hz, 350Hz,
500Hz, 700Hz, 1Hz, 2 KHz, 2.8KHz, 14KHz. Some of those seem strange, but
that's what the schematic says.
The input stage has a one-transistor amplifier, and the output stage was a
two-transistor deal. The filter stages were all
poteniometer/2-inductors/3-capacitors/3-resistor deals.
Two of these ten-band (sic) filter banks were the core of Wendy Carlos'
ten-band vocoder as first used ion her Beethoven's Ninth Symphony, and soon
after in Timesteps, as heard in "A Clockwork Orange." She had Moog give her
jack-access to the filters so that she could run the first bank of separated
signals into envelope followers, and the ten from the second FFB into VCAs.
When the former controlled the latter, she had a simple vocoder.
Later, Moog produced the Model 914 FFB. The design was very similar to the
former, but with 14 bands of resolution. Only "Lo Pass" and "Hi Pass" are
marked on the schematic. I'm too tired to do the math to figure out the
center frequencies of the bands.
Hope this helps.
-----Original Message-----
From:
JWBarlow@... [mailto:
JWBarlow@...]
Sent:Tuesday, October 05, 1999 10:04 PM
To:
motm@onelist.comSubject:Re: RE: [motm] Anybody like Fixed filter
banks?(new mod)
From:
JWBarlow@...I used the Moog (8 band as I recall) and I liked it. It may
have just been
passive as Mark (?) said, but I seem to recall that it had a
nice
distribution of bands -- was it musical 7ths or 9ths? (It
might not be very
exotic nowadays when compared to all the EQs available) Does
anybody know how
the bands were arranged?
JB
In a message dated 10/5/99 7:46:22 AM,
daveb@... writes:
>The Moog fixed filter banks are fixed frequency AND
resonance, so no better
>than a common graphic eq. Just a gain control for each
band. If I remember
>right, there is an 8 band and a 12 band version, each with
an additional
>low
>and high shelving control.
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