hello,

after one week off i'm back with some notes on
several modules and some sound examples for
the a101/1 vactrol steiner filter.

the notes first:

last week i've received two a152 modules.
the a152 is a great tool and especially users
with larger systems will love it. it offers
lots of possibilities and functions.
it is so much more versatile to use a cv
to adress the active port, instead of cycling
through the positions with a trigger pulse.
but the true strength of the module is the
track&hold part. used in conjunction with
a bunch of vco's very interesting melodies
can be generated. the a152 is also of great
value when used with the a101/3 or several
filters, lfo's and envelopes.


i also got my old filters back, with a more
sensitive input stage.

my result is that the a120 lowpass filter greatly
benefits from this modifcation. i can really
recommend this and i like the new behaviour of
the a120 a lot more than before. it sounds
much more like a real moog filter now,
very similar to my old moog prodigy some
years ago.

the a121 significantly changes in sound when
it is overdriven. it starts to sound more harsh
and it produces distortions which sound totally
different than on the modified a120.
so it is a matter of taste, if someone should
modify the a121 or leave it as it is.
i'm happy with the modification.

the a122 can only barely improve the range of
sound with the modification. the only thing is
that now it is easier to handle low level input
signals. in my opinion it isn't really
necessary to modifiy the a122, unless someone
has serious problems with processing of
low level signals.

finally, the a123 highpass filter cannot be
modified to have a more sensitive audio input,
despite what is said earlier. imho this wasn't
really necessary for the a123 anyway.


ok, now some short sound examples for the a101/1
vactrol steiner filter. each file is about 90 kb.


example 1 uses different waveforms for each input.
a111 pulsewave at the lowpass input, the sawtooth
of a second a111 at the highpass input and the
pulsewave of the second a111, divided by an a163
at the bandpass input. the filter cutoff was controlled
by the pitch cv and a bit of negative a140 adsr.
the filter was close to self-oscillation.

http://www.selfoscillate.de/a100files/a101-1-example-1.mp3


example 2 uses an a111 pulsewave, panned manually
with an a134 panning module between lowpass input and
highpass input.

http://www.selfoscillate.de/a100files/a101-1-example-2.mp3


example 3 uses the a111 pulsewave at the lowpass input.
the same pulsewave is fed into an a125 phaser and then into
the highpass input of the a101/1. only the phaser is swept
by an a145 sinus, not the a101/1.

http://www.selfoscillate.de/a100files/a101-1-example-3.mp3


in example 4 the same a111 pulsewave is fed into the bandpass
input and also into an a196 pll and an a101/3 vactrol phaser.
the pll output is going into the lowpass input, the phaser
output (6-stage) is going to the highpass input.
two a147 triangle lfo's modulate the a101/1 cutoff and the
a101/3 phase shift. notice the change in the melody, this is
caused by the pll.

http://www.selfoscillate.de/a100files/a101-1-example-4.mp3


the last example shows an a101/1 with overdriven input
stage and full resonance. the a111 pulsewave is sent into
the lowpass and bandpass input. (lp in = 10, bp in = 5,
hp in = 0, res = 10). filter cutoff is modulated by the
pitch cv, an inverse a140 envelope and an a147 triangle wave.

http://www.selfoscillate.de/a100files/a101-1-example-5.mp3


best wishes

ingo