Subject: Taurus Patch Programming #6
Date: Tue, 13 Jan 1998 17:37:30 -0800
From: timkoelm@iconz.co.nz
To: jv1080@emccta.com

Greetings JV/XP'ers!

Welcome to the sixth installment of my patch programming series.

This past week, I ran out of patches to present, so I had to put the gas on and program
a few more. I came up with 3 new patches and here's one of 'em - 'Vintage Dyna Pad'.
This is one of those patches which use the Structures - Structure 3 to be precise, which
uses the Booster. See last weeks post for additional information and thoughts on the
Boosters and Structures.

I find that simple synth waves work best with the Boosters. So in this patch, I've used
four sawtooth waves run through Structure 3, which puts a Booster before one of the
TVFs. By now, you should be cottoning on to particular techniques I'm using to create my
patches, if you've been reading my patch posts from the first series. There are a few at
work here. One is the technique of creating a patch using two tones and copying those
finished tones for the completed patch. Another is using various programming techniques
to create movement in a sound.

So, for tones 1 and 2, I've selected sawtooth waveforms and detuned them seperately.
I've used a rather different detuning method here though, the Random Pitch Depth
parameter. This detunes tones up or down by a maximum number of user-selected cents.
Apart from being small-change, a cent is also 1/100th of a semitone. So, by selecting a
Random Pitch Depth value of 10, I'm detuning each tone by a maximum of 10 cents in
either direction on each keypress. I find this to be slightly more 'organic' than simply
detuning waves against each other, although the natural chorusing effect may be slightly
exaggerated at times, depending on how extreme a value you've set. Another important
factor at work here is 1/f modulation, also known as 'Analog Feel' (under PATCH/COMMON/
GENERAL). It's cranked to a value of 40, and even at this medium setting its effect is
heard quite clearly. This random detuning between oscillators reminds me of the slightly
sick Sequential Prophet T8 we've got down at the local music store at the moment.

I've employed a LPF on each tone to remove high-frequency content from the raw waveform.
Remember that certain analog synths of the past (the Minimoog springs to mind) didn't
actually have a completely 'flat' filter - there was always a certain amount of
resonance (or 'emphasis') present. Therefore, I've also added a hint of resonance to the
filter for each tone. The TVA is set for an instantaneous attack and a moderate release.
The decay in tone you're hearing isn't from the TVA however, it's from the TVF. Examine
the TVF envelope closely, and see how I've set the values to achieve the characteristic
decay - experiment and listen. The LFO's are not employed in this patch. Tones 1 and 2
are then copied and pasted to tones 3 and 4.

The completed tones are then piped though Structure 3. When all four tones are at work
in a patch and you're using the Structures, there are a couple of important things to
remember. Here's a mini schematic of Structure 3:

******************************************************************

WG ---- TVA ----|---- TVF ----|
                |             |---- BSTR ----|
WG -------------|                            |---- TVF ---- TVA

******************************************************************

WG   -  Wave Generator
TVA  -  Time Variant Amplifier
TVF  -  Time Variant Filter
BSTR -  Booster

The waves of tone 1 and 2 (or 3 and 4) are mixed by the TVA of tone 1, and then are
filtered by the TVF of tone 1 before being put through the wave Booster. The Boosted
signal is then filtered by the TVF of tone 2 and the master output is controlled by the
TVA funtions of tone 2.

In this patch, for tones 1 and 2, 100% of tone 2 is mixed with tone 1, and a certain
amount of high-frequencies of the combined signal are cut *before* being put through the
Booster, as the TVF for tone 1 is located *before* the Booster in the signal chain. The
more high-frequency content contained in the signal before boosting, the more of the
signal is boosted, clipped and distorted, and therfore the more the high-frequency and
pulse wave distortion in the Boosted signal. How much the signal is boosted by is
controlled by the Booster level, which amplifies the wave by +6, +12 or +18 dB. I've
chosen a value of +12 here, which introduces quite a bit of distortion - it's part of
this patches' charm. The TVF of tone two can be used to shape and control the amount of
distortion and high-frequency content in the boosted signal, as tone 2's TVF is located
*after* the Booster in the signal chain. That's what I've done in this patch. Try
disabling the TVFs for tones 1 and 3 first, and then tones 2 and 4. Listen to the
differences, subtle and not so subtle.

Also remember that the master output of the signal is controlled by the TVA functions of
tone 2 (or 4). So all panning and TVA functions for the pair of tones fed into the
Structure are controlled by tone 2 (or tone 4). Try adjusting the pan position of tone 1
(or 3). Then try adjusting the pan position of tone 2 (or 4) Hear the difference? So in
this patch, to obtain a stereo image using for tones, I've panned tones 1 and 2
hard-left using the pan control of tone 2. Likewise, I've panned tones 3 and 4
hard-right using the pan controls of tone 4. If the TVA of tone 2 (or 4) is turned all
the way down, you'll hear zip. Any questions? All I've described above is a common
technique I use for programming basses, leads and pads.

I decided this patch was so huge-sounding it didn't need the EFX processor to 'make' its
sound. I've just used the master Reverb and Chorus processors to add a finishing sheen -
this patch is still fun to play with the effects disabled. Try programming it with the
Stereo Chorus, Hexa-Chorus or Modulation Delay programs. You may also want to compare it
to internal preset A:66 Saw Mass, which is similar in style to 'Vintage Dyna Pad'. I'd
say this patch sounds at least twice as big!

Well, that's it for this week. Any comments, suggestions, constructive criticism, just
email me, I'd really appreciate it. I have to say, it's high time a few of you other
patch programmers out there (budding or otherwise) shared your patches, tips and tricks!
The More the Merrier!!

Best Regards,

Taurus3

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