STOMPER Ultra++ 4.0
The Drum Sound Synthesizer

The Manual!

By Håkan 'Zap' Andersson

Hear Master Zap MP3's
Some of which uses STOMPER drums!


STOMPER is a Microsoft Windows1 software synthesis program for drum-like sounds. The latest version of STOMPER can always be downloade from (Official URL)
or (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:

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:

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:

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. 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

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
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.!!

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!!
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....
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!