STOMPER Ultra++ 4 Manual, by Zap

STOMPER Ultra++ 4.0 The Drum Sound Synthesizer
	The Manual!
	By Håkan 'Zap' Andersson Email zap@Master-Zap.com WWW: http://www.Master-Zap.com Hear Master Zap MP3's Some of which uses STOMPER drums!

Introduction

STOMPER is a Microsoft Windows¹ software synthesis program for drum-like sounds. The latest version of STOMPER can always be downloade from

http://www.Master-Zap.com/stomper/ (Official URL)
or
http://www.lysator.liu.se/~zap/stomper/ (Backup URL)

STOMPER uses a very simple synthesis method, mixing pitch-shifting narrow-band noise sources or pure sine waves (zero bandwidth noise, really) together to one sound.

STOMPER ULTRA+ also allows different waveforms, and resonant filters, allowing you to simulate old vintage synth sounds.

STOMPER ULTRA++ allows you to load WAV files as oscillators, allowing you unprecedented WAV-mangling capabilities, to make tape-stop effects, scratch-effects, add distorsion and filtering to WAV's, and more, and more, and more....!!!!

STOMPER ULTRA++ 4.0 (the version you have) ALSO allows oscillators to modulate eachother, which means you can create ring modulation, FM-synthesis, vibratos, tremolos, modulated filters..... how about modulating the cutoff frequency of a WAV file with another WAV file, amplitude modulated by a pitch-modulated sine wave? Sounds like fun? IT IS!

STOMPER does not:

...add reverb or other special processing. Use a tool such as CoolEdit to do that!
...sequence the drum sounds into a Pattern or Loop. STOMPER only creates the individual sounds.
To sequence them, I suggest you try one of:
- "Little Drummer Boy", the drum loop software by Zap, the Author of Stomper!
- "HammerHead" by Bram Bos, the "good old" loop software. A bit limited, but completely free.
- "Making Waves" by Perceptive Solutions

The Theory

Old analog drum machines, such as the beloved TR-909, TR-808, and others, often used a fairly simple analog schematic to do their synthesis of drum sounds. One common component was a "ring circuit", which basically is a circuit tuned to near-self-oscillation. That means, that it yields a pure sine-tone with diminishing amplitude.

By also pitch-shifting this, or waveform-distorting it, a wide range of plop-like sounds can be created. Combining a very low-pitch "plop" sound (more like an "oompfh", really) with a very short and hi-pitched one (more like a "klick"), you have a pretty nice kick drum, as in the old 909.

Pitch up the "oomph" part, and add some narrow band noise. Now you have a snare drum.

Prolong the length of the tone, make the pitch-drop more evident, and dampen the noise a bit. Now you have a Simmons tom drum.

And so on...

Now, I am not claiming STOMPER accurately models the actual analog synthesis in any of the above mentioned devices. But I do claim that STOMPER is capable of creating a fairly powerful set of drum sounds, some very close in sound to the old Analog machines. Some better!

Also, STOMPER ULTRA goes beyond this simple synthesis model, and incorporates different waveforms and resonant filters into the design. STOMPER ULTRA++ goes further, and adds WAV as a waveform.

Since STOMPER is pure Software Synthesis, there is no signal-to-noise ratio to worry about. Everything is 100% pure 16 bit samples, with perfect studio clarity. (n.b. if you use WAV oscillators, quality depends on your source .WAV!)

The Practice

In the theory above, the components used to make Drum sounds sine curves diminishing in amplitude (and optionally frequency) over time, coupled with narrow band noise, with some optional filtering.

STOMPER ULTRA takes this a bit further, and allows you to mix up to 512 general oscillators and filters. This is done in the following dialog box:

Each oscillator has a tab in the main dialog with it's number on it. If the number is within parenthesis, the oscillator is disabled. You can create new oscillators at the last position by clicking the "(new)" tab. You can also insert and delete oscillators at other positions using the Edit menu.

Each oscillator has the following parameters:

State: Each oscillator is either On (it sounds), Off (it makes no sound and does not calculate) or Inaudible which means it is calculated, but does not output sound. This is useful when you want to modulate one oscillator with another.
Start time in milliseconds, 0 is the beginning of the sound
End time in milliseconds. This Oscillator will make sound between these two times.
Start frequency the frequency of the wave (or center frequency of noise) at the beginning (at Start time)
End frequency the frequency at End time.
Frequency Modulator Choose which other oscillator modulates this oscillators frequency
Frequency Modulation amount Choose how much to modulate. Positive values are interpreted as deviations around the base frequency (= vibrato and FM synthesis), but negative values are deviations around the zero-frequency (= frequencies are multiplied - sonic insanity!).
Start amplitude the amplitude (loudness) of the oscillator at Start time.
End amplitude the amplitude at End time.
Amplitude Modulator Choose which other oscillator modulates this oscillators amplitude
Amplitude Modulation amountChoose how much to modulate. Positive values are interpreted as deviations around the base amplitude (= a tremolo effect), but negative values are deviations around the zero-frequency (= amplitudes are multiplied - ring modulation)
Waveform selectable between Sine, Square, Sawtooth, Triangle and WAV file.
If you select WAV:
- ...you will be prompted for the filename, and if the file should be looped or one-shot
- ...the "frequency" of the oscillator will be the sample frequency the sample will be replayed at. This can be set Automatically.
- ...if the sample is in the same directory or one below the .STU file, only the relative path is stored, to make portability of files easier.
Noise factor the bandwidth of the noise. If zero, this is a pure sine/tri/e.t.c.wave. Larger values yields broader deviation from the base frequency, i.e. broader band noise.
Noise type defines the frequency shift rate² of the noise.
And finally, the fun parts of Stomper:
Frequency Curve shape You can define the curve shape of the frequency change, either by typing a value, dragging the slider, or by dragging the mouse in the curve shape window. Normally, dropping quickly in the beginning and slower towards the end is best for drum-like sounds. Often the percieved pitch of a sound changes together with the curveshape! If you feel the pitch of your drumsound is wrong, it is often a good advice trying to alter the frequency curveshape first, instead of the actual frequencies.
Amplitude Curve shape As with the frequency, you can decide how the amplitude changes.
Tone Curve shape Finally you can define the curveshape of the sine/tri/e.t.c. curve. This is sort of a "distorsion" feature (particulary evident on WAV files!!) You can go all the way to complete 100% distortion (pure square wave) if you like... but a light distortion is often ehough to give the tone "character".

For your convenience when making tuned (musical) sounds, there is a "musical frequency calculator" built into STOMPER ULTRA. You can access it from the menu,

or from the little button between the frequency edit boxes.

Also, each oscillator may be turned into a filter instead, by checking the filter control. When it is in "filter mode", the following controls are changed:

Start and End frequency now becomes the Start and End Cutoff Frequency of the filter.
Start and End amplitude now becomes the Start and End Resonance factor (in a range of 0 to 1) of the filter.
The Waveform selection and Tone Curve Shape graph disappears.
When an an oscillator is in filter mode, it's number is indicated with an F in the associated tab.
The filters will filter all oscillators AND other filters to the left of them (i.e. with a lower number), during the set time interval for the filter. This means that in the example picture above (available as SY-SWEEP.STU in your STOMPER ULTRA installation):
- Filter F3 filters the output of oscillator 1 and 2
- Filter F4 filters the output of filter F3 if their time interval overlaps, or if their time interval does not overlap (which happens to be the case in this particular example file), it also filters oscillators 1 and 2.
- No filter affects oscillator 5.

Everytime you hit the Play button, the sound is recalculated (if needed) and played through your soundcard³. This button is the default, so if you just hit the Enter key, the sound is played.

If you hit "Play" again without changing anything, the sound isn't calculated again, but played directly.

You may also use the "Auto beat" feature by checking the "Auto" box, and enter a BPM value beside it. Stomper will automatically hit the "Play" button for you with these intervals (Note: very approximate and in no way accurate timing!!)

Tricks & Tips

To avoid clipping your sounds, use the Normalize amplitudes function from the Tools menu.
Stomper puts temporary files where the TEMP environment variable points. This should point to a directory, and have no trailing backslash. This is normally done automagically by Windows.
Experiment with the sample sounds (Load the .STP "stomper settings" or .STU "stomper ultra settings" file from the menu) to get a feeling for how things work.
When saving, only the enabled oscillators are saved!!!
If you get bored, try the Fun menu.
A special feature known as "phase continuation" exists in STOMPER ULTRA. If one oscilltor ENDS at exactly the same time as the next oscillator (with next higher number) begins, the phase of the waveform will be continued from the previous oscillator, to avoid clicks/pops at the transition. Otherwise, the oscillator always starts at the beginning of the waveform.

Legal Stuff - MusicWare

The Stomper Licence Agreement

Stomper is MusicWare, that means that it it doesn't cost you anything except Music! If you use STOMPER sounds in your music, you are kindly asked to send some of it to me (for my listening pleasure only - you retain all ownership to your music, of course!). A normal casette tape is sufficient, although if you make a commercial CD, tape, or Vinyl, you must send one (1) copy of it to me!

My snailmail address is:

Håkan 'Zap' Andersson
St Almby, Hagby
S-635 05 Eskilstuna
SWEDEN

Note: This licence agreement is not a joke, and I am serious, and as all licence agreements, it's legally binding. I don't charge money for Stomper, I charge "music". It's a win/win situation where you get your music spread, and I get my software spread. So send those CD's, tapes, e.t.c.!!

Footnotes:

1)
No specific Macintosh of STOMPER version will be written - but there is a plan for a Java version, which will run on all platforms supporting Java - which naturally includes the Mac! But note that Stomper runs perfectly fine under SoftWindows!!
2)
If this parameter is zero, the waveform shifts frequency each time it crosses zero. This yields a "rough" noise. Any value of 1 and above causes the tone to change frequency when such many samples have been output (and hence this parameter is dependent on sample frequency!).
With a sample frequency of 22000 hz, and a noise change rate of 1000, it means the tone will shift frequency 22 times per second, which sounds more like a digital watch than noise. That can be a nice effect, though....
3)
Any soundcard should do fine - STOMPER uses the sndPlaySound() function to play the .WAV files. Note however, that some soundcards only support the "standard" sample rates of 11025, 22050 and 44100 hz, and still some, only 44100!

The Manual!

By Håkan 'Zap' Andersson

Introduction

The Theory

The Practice

Tricks & Tips

Legal Stuff - MusicWare