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Free Rez
 Free Rez |
There
was once a
time that I didn't have a resonant filter in any of my
gear
at all and as this was something I really desired for my songs, I built
one.
I built the device on the left (of course there is only one in the world :) ) by modifying a circuit for a guitarist's analogue wah-wah pedal, the design of which was in an electronic projects for musicians book! The case (which had been used for many projects before) was an afterthought and I recorded several songs using the device before I even finished it! |
In the first instance the unit worked by taking an input signal and manually filtering it according to the controls. During building, rather than deciding exactly how much resonance etc was to be given, two controls were added, one for course (such as a switch) and one for fine (a potentiometer).
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Envelope and pseudo - midi ability was then added by controlling the cutoff with an opto isolator as well as the manual controls. The opto was driven by another audio input. The waveform for this was a sharp 'stab' sound to start the curve and then the discharge of a capacitor was varied for decay. |
Not shown in the diagram is the ability to vary the type of filter, high, band or low pass or varying quantities of each. In this diagram the 01/W is set up to output a sharp percussive sound on the right channel "R" and a sound to be filtered on the left channel.
The system works particularly well with raw sounds rich in harmonics such as saw and square waveforms, but also sounds good with other sound such as choirs or drums - even a whole song!
The analogue resonant filer of this home built electronic device allowed me to create lovely acid sounds without the heavy expense of a factory built professional analogue synthesizer.
Hear the Free Rez in action!
"Paradise"
(115 K low quality MP3) "The
Bill" - section 1 (329 K MP3) "The
Bill" - section 2 (167 K MP3) The free
rez has
been superceeded by the Novation now but
was
used in earnest for around 4 years.
Casio VZ10M
VZ10M
This section is not necessarily completed!
This instrument was given to me many years ago by and old friend. The VZ was quite ground breaking in it's time as it had very flexible sound options but was (or at least I found it) difficult to program.
Another problem for the VZ was it came out at a time when other programmables were starting to offer realistic waveforms based on PCM or samples. The base waveforms were all saw wave derivatives with the exception of a sine wave and it used additive synthesis.
Both the VZ and the CZ below used a synthesis technique called PD or Phase distortion - rather an unfortunate name! The CZ offered a solution to resonant filters which was easily accessible that the VZ doesn't.
It was featured in some
of my older
songs but has not been used since 1991!
Casio CZ101
This section is not necessarily completed!The first programmable synthesizer I played with was the Casio CZ101. We had one in the family from when they first came out but I quickly 'adopted' it for personal use!
The CZ was a small plastic unit with a four octave keyboard and a large pitch bend lever to the left. The readout is a two row matrix display which shows the selected patch or the parameter being edited.
Patches were edited simply by selecting the required parameter ie Waveform and changing it's value using the up/down keys.
Source waveforms included sine, square and some really nice resonant ones, the resonant frequency being changed with the DCW curve - like having resonant filters but for additive synths!
The CZ had a polyphony of
four
notes and these could be stretched over four MIDI channels - each with
a different patch giving a primitive form of multitimbrality. Yazoo!
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In future I may expand these sections to include more technical data and diagrams if there is demand!Tracked by dancecrave"; ?>