These notes will help you get the most out of the plugins in the Psycho Toolkit bundle.
The OTT warmth-adding analogizer thingy (there's one born every minute...)
Barnum Preamp explores the idea of adding analog warmth to a sound by splitting it into three frequency bands, giving you level control over those bands, and adding a variable amount of silky smooth distortion to the midrange band, and no doubt subtly messing with both the frequency and the phase response.
People pay huge sums of money for preamps that do this sort of thing, and go totally thesaurus describing how fantastic it makes their sound.
There's one born every minute.
If you've ever listened to one of these high-end boxes, but been too ashamed to admit you can't hear what all the fuss is about, then have I got a deal for you!
Seriously though, by playing around with the settings of Barnum Preamp, you'll hear how a small amount of very gentle distortion in the midrange (together with boosting the bass slightly and turning the treble down a touch) can give you a really creamy sound.
And of course in true Psycho Toolkit style, you can always take it too far... in a good way!
The Bass Gain knob controls how much the bass frequencies are cut or boosted.
The Mids Center Freq knob determins the center frequency of the midrange band.
The Mids Width knob controls how wide the midrange band is. The Midrange band is constrained so that cannot go outside the range of 50 to 16000 Hz, if you choose settings that try to go outside this range the numbers will be trimmed back. The actual crossover frequencies are displayed in little "LCD displays" underneath the knobs.
The Mids Drive adds a smooth distortion to the midrange band. Barnum Preamp uses a soft clipping algorithm called the sigmoid function. At high settings this produces a classic overdriven sound, but does not totally destroy the sonic detail of the incoming signal. At lower settings it can add a warmth rather than obvious distortion.
At the minimum setting no distortion is added, it's a straight bypass.
The Mids Gain control gives you level adjustment, you'll probably need to adjust it as the Drive knob can boost level of the midrange band.
The Treble Gain knob controls how much the treble band is cut or boosted.
The aural enhancer / exciter that goes too far.
Excitable Boy enhances an audio signal by isolating the bass and treble portions, and applying separate distortion to them to generate more bass and treble content.
When this technique is appled subtly, the distortion is not noticable as distortion, rather it adds a candy gloss to the sound. Several plugins and hardware processing units on the market use this technique.
Excitable Boy doesn't like the idea of applying effects subtly.
Excitable Boy doesn't know when to stop.
Excitable Boy goes too far.
Of course, if you want a standard enhancer, you can turn all the knobs down low, and get that suble glossy sheen.
The Bass Cutoff knob controls how much of the bass portion of the signal to enhance. Low values will only process the very lowest frequencies, higher values will include some low-mids as well.
The Bass Drive knob controls how much distortion is applied to the isolated bass portion of the signal. Low values will generate a few subtle harmonics, high values will generate extreme distortion and even noise.
The Bass Mix knob controls how much of the distortion is mixed back in.
The Treble Cutoff knob controls how much of the treble portion of the signal to enhance. Low values will include quite a lot of mids and high-mids, higher values will only process the very highest frequencies.
The Treble Drive knob controls how much distortion is applied to the isolated treble portion of the signal. Low values will generate a few subtle harmonics (high-frequency content that wasn't in the original signal), high values will generate extreme distortion and noise.
The Treble Mix knob controls how much of the distortion is mixed back in.
The Mode buttons switch between a simple soft clipping distortion and a more exotic sinusoidal algorithm. As low drive settings the results are quite similar, high values make the difference more apparent.
Finally there is a Gain knob to adjust the output level, as lots of drive and a high mix value can boost the volume way too high.
The rectification-based and playback speed octaver with an attitude problem.
Flip Speed generates octaves by two methods: flipping the polarity of the incoming signal at cycle boundaries, and playing the signal back at either half or double speed. It works best on monophonic sources - leads, basslines, melodies, even vocals. If you use it on tracks with no clearly-defined pitch (such as mixes, chords or drums), you will get unpredictable results and distortion - nasty... or interesting.
Even with perfectly monophonic sounds it is not an exact science - you will probably not get pure octave tones (at least, not from the wave flipper channel), so it is not a transposition effect.
The Octave switch lets you choose between an octave below the input signal, and an octave above. The Flip channel will be generating sub-harmonics and harmonics rather than transposing the input. For the octave down, every alternate cycle is flipped, generating a sub-harmonic one octave below the input. For the octave up, the entire signal is rectified - the portion of the waveform below zero is flipped above zero, generating an octave harmonic.
The Speed channel on the other hand will be playing back the wave cycles at half or double speed, skipping or repeating cycles to "keep pace" with the original.
The Pre Filter knob controls a simple low-pass filter to remove some of the higher harmonics before the rectification is performed. This can reduce glitching and make the generated octaves clearer, but of course you are losing some of the clarity of the original signal.
The Speed channel operates on the unfiltered original signal, since it is more robust.
The Blend knob controls the mix of Flip and Speed channels.
The Distortion knob drives the rectified signal into a smooth clipping algorithm, giving an edge to the sound.
The Post Filter knob controls a low-pass filter after the octave generation performed. Rectification generates quite a lot of high-frequency harmonics and artifacts in addition to the octaves. The Post Filter can smooth these out a little if you like.
Also, since the Speed channel did not operate on a filtered waveform, you may want to filter out some of the double- or half-speed harmonics.
The death metal vocal effect that defiles even the purest voice.
Metal Demon works best on solo vocal tracks, before any echo or reverb has been applied.
The Balls knob controls how butch the voice sounds, ranging from almost natural to diabolically deep. Metal Demon always transposes the vocal one octave down, the Balls knob changes the vocal characteristics or formants.
The Throat knob controls how hoarse the demon's larynx is, from relatively clear to totally tortured.
The Muffling knob adds further control to how clear the vocal sound is. The minimum setting is quite clear but may have some edgy glitches, higher settings will reduce the glitches but also the clarity.
A word about FFT-based vocal format shifting
Metal Demon works by dividing a small "chunk" of sound into a large number of frequency-based components. This is done using a method called "fast fourier transform", or FFT for short. After the sound is divided, some of the components are shifted, changing their frequency.
(More notes on FFT appear below in the Water Glass section).
The seriously twisted wave-peak analysis distortion generator.
Sick Puppy generates distortion by analysing the incoming waveform, using a variety of techniques to identify the peaks that define each cycle. The output waveform consists of the value of each identified peak, held until the next one is detected.
Originally this analysis was not intended as an effect, rather it was reseach into methods of partitioning an incoming signal to process each wave cycle separately. However, while listening to the output I discovered that it was capable of producing some extreme and unique distortion effects, particularly when filtered before and after the peak-stepper algorithm.
The wave peak analysis works best (the way I originally intented it) on periodic waveforms. That means monophonic pitches - solo lines, basslines. However for destructive sound design there are no rules...
The Mode switch lets you select four variations of the peak analysis algorithm.
Mode A is a simple sample-and-hold on the peaks and troughs, I originally intended this for signal conditioning.
Mode B adjusts the value of each peak so that it is the difference between it and the previous trough. This "normalisation" was originally intended to make it useful for pitch tracking.
Mode C weights the value of each peak by the area of the surrounding triangle formed by the adjacent troughs.
Mode D weights the value of each peak by the absolute value (ie, how var the value is above or below the zero line).
These are pretty esoteric differences, and if you observe the waveform graphically you might understand what is going on better. The important thing is that they create different distortion effects, particularly if you filter the signal before and after.
The Pre Filter knob controls a simple low-pass filter to remove some of the higher harmonics before the wave peak distortion is performed. Lots of filtering (a low cutoff frequency) can reduce glitching and make the fundamental pitch stand out.
The Drive knob adjusts the gain as the output from the distortion engine can be very unpredictable.
The Post Filter knob controls a low-pass filter after the distortion is generated. The wave peak stepping algorithm generates a "stepped" waveform, with quite a lot of high-frequency harmonics and artifacts present. The Post Filter can smooth these out a little if you like.
The vacuum tube and cheap amp construction kit.
Trash Triode lets you create the warm compression-like distortion sounds produced by very old vacuum tubes (valves) and cheaply-designed amplifiers. Its construcion kit layout lets you control all the defects and shortcomings that more advanced designs have eliminated or refined.
In the Pre EQ section has four controls: Treble, Mid Freq, Mids and Bass. These give you some basic EQ to adjust the tone of the incoming signal, before any further processing.
The Defects section lets you control three of the most common design flaws of very cheap amps: Noise, Hum and Rail Decay. Rail Decay is what happens when the power supply is not adequate for the level of output. In other words, when you play a cheap amp too loud. If you have a loud, sustained sound it will be played at full volume at first, but then the power supply is drained, and the level will fall. After a short period of silence (or low-volume signal), the power supply becomes charged, and the output is full volume again.
This effect can be difficult to control, and is most predictable when you have sustained notes (or chords) with pauses or breaks in between them. The outcome of this this can be useful musically - it can enhance the attack of sustained sounds, or since it also affects the drive into clipping, it can change their tone making them more distorted at the beginning, then less so as they sustain.
Trash Triode lets you control the Rail Decay Time - how quickly the level drops, and the Rail Decay - the amount by which the level drops.
The Distortion section is where most of the destructive action takes place. There are two types of distortion available:
Clipping. This is the most common type of distortion, and you are no doubt familiar with it. Trash Triode uses a soft clipping algorithm called the sigmoid function. This produces the classic overdriven sound, but does not totally destroy the sonic detail of the incoming signal. In fact, at certain settings it has a distinct compressed character. The Clipping Drive knob controls how much clipping is done.
Slew Rate Limiting. Instead of limiting the signal level (which is what clipping does), slew rate limiting affects its slope - that is, how fast the voltage can rise or fall. Old vacuum tubes simply couldn't change the voltage fast enough to perfectly track the signal, and this kind of distortion is the result of that.
In practical terms, slew rate limiting rounds off some of the edges of the sound, loses some of the definition, and reduces the volume. Trash Triode offers Pre Slew Limit (slew rate limiting before clipping is performed) and Post Slew Lim, which is done after the clipping and has a more dramatic effect.
The combined effects of these operations means that the output level is pretty unpredictable, so a Gain Adjust knob is provided.
The Cabinet section gives some very basic tools to simulate an old speaker cone and cabinet.
Cabinet Size is nothing more than a comb filter, the knob controls the delay amount (0.2 to 12 ms). This may help simulate the boxy sound of a poorly-designed cabinet.
The Reso Freq and Reso Amount knobs control a resonant or peaking filter, further simulating a speaker box. (The Reso Amount also controls the intensity of the comb filter.)
The Buzz knob dials in some speaker cone buzz, further dirtying the sound. You can only control the level of buzz here. To change its quality, use the Post EQ section.
In the Post EQ section mirrors the Pre EQ with Treble, Mid Freq, Mids and Bass. These give you some final EQ control over the output.
The noise reduction and texture generating plug-in.
The two controls in the first section may seem odd at first, but they are there for a reason.
The Noise control lets you add white noise to the signal, while the Distortion control applies very high gain and consequent harsh digital clipping. These are normally not something you'd want to do to your audio, in fact you often go to great trouble to prevent this sort of thing from happening. If you are using Water Glass for simple noise reduction then please - leave both of these settings in the Off position!
However, if you want to use Water Glass as a sound design tool to create sonically interesting pads etc, adding some "dirt" to the sound can give the algorithm something to "sink its teeth into". You can also experiment with them to hear how noise reduction works.
The controls in the middle section shape the noise reduction processing.
The Mode buttons switch between two types of noise reduction. In Cut mode, parts of the sonic spectrum that are considered noise are cut out entirely, and the rest of the signal is left alone. Reduce mode goes further, it reduces the entire signal by an amount corresponding to what it considers noise. There are no rules, but Cut mode can sometimes generate more interesting artifacts, while Reduce may give a smoother, more natural sound. Likewise, if you have switched to Residuals (see below), Reduce mode might sound better.
The Granularity knob controls the size of the chunks of signal that are processed. In general, larger chunks will give a smoother sound for "regular" noise reduction, and tinkly, "arpeggiator-like" artifacts at more extreme settings. On the other hand, smaller chunks will give a smoother sound if you have switched to Residuals.
The Depth contol determines the amount of noise reduction, from almost none at all, right up to cutting out pretty much all of the incoming signal. For true noise reduction, try to set this as low as you can while still getting the noise reduction you require, because higher settings mean more artifacts. For sound design purposes, set it as high as you like. If you have put some "dirt" into the signal, you'll need higher settings to get rid of it (and produce more artifacts).
The Contour contol lets you perform more noise reduction at lower or higher frequencies. When the knob is in the middle, the same amount of noise reduction is performed across the audio spectrum. At the "Bass" position, more cutting/reduction is performed on the higher frequencies, while the "Treble" position causes more processing is done on the lower frequencies. The effects of this can sometimes be subtle, and after adjusting this knob you may need to readjust the Depth.
The controls in the final section determine how the processed signal is output.
When the Residuals switch is off, the noise-reduced signal is sent to the output. If you switch Redisuals on, the difference between the pre-noise-reduction and post-noise-reduction signal is output. In other words, you get to hear what the noise reduction algorithm "cuts out". Note that if you have added Noise or Distortion, the residuals will include this, and probably sound very nasty. However with certain settings and signals, the Residuals output can have a ghostly, haunting, etherial quality as opposed to the glassy, liquid sound you'll get with Residuals switched off.
The Gain contol lets you adjust the volume of the output signal. High Distortion settings will tend to increase the volume, while high settings of the noise reduction Depth will decrease it.
A word about broadband noise reduction
A basic broadband noise reduction algorithm works by dividing a small "chunk" of sound into a large number of frequency-based components. This is done using a method called "fast fourier transform", or FFT for short. After the sound is divided, each component is examined, and the question is asked: "Is this component most likely caused by noise, or the original signal?" If the answer is that the most likely cause is noise, that component is removed or reduced, otherwise it is left alone. This is then repeated for the next "chunk" of sound, and so on.
One issue with this method is that sometimes the computer gets it wrong - a small frequency-related component of the sound may be caused partly by noise and partly by the original signal, or indeed mostly by the original signal. The more noise reduction you ask for, the more likely the computer is to get it wrong.
The results of "getting it wrong" is that parts of the sound that should be left alone are removed. This leads to the so-called "burbling" artifacts that characterise "too much" noise reduction.
If there is so much noise (or distortion, or other unwanted components) in a signal, then certain levels of noise reduction will produce burbling artifacts, but even so, still let some components of the noise or distortion through. In other words, there is both too much noise reduction, and not enough. The components of noise that are "let through" can however be quite interesting - reminiscent of scintillating chimes.
Water Glass was especially created to produce these different types of artifacts, although you can also use it as a "normal" noise reduction plugin.
Buffers and Latency
The following comments are based on the maximum Granularity setting. Lower settings are less likely to cause significant delays.
Water Glass uses FFT (fast fourier transform) to perform pitch tracking and morphing filtering. This is a powerful mathematical technique, but it needs to work on rather large chunks of audio data at once (around 100 milliseconds). However, if you like to use VSTi and DXi soft synths, you probably have your PC and audio host app set up for low latency – which means that processing plugins like Water Glass are only passed very small chunks of data (sometimes less than 10 milliseconds).
If you are running the DirectX version of Water Glass, and it decides that the buffers are too small, it switches to Buffer Accumulate Mode. When this happens, Water Glass will introduce a short delay between the input and output, because it has to "accumulate" a buffer full before it can process, meaning that the output data is 100 ms "behind the times".
There are two things you can do about this: (1) go into your host app’s audio settings window, and increase the latency/buffer sizes, or (2) drag the audio data 100 ms to the left after processing it.
The VST version of Water Glass won’t exhibit this delay under most hosts, because VST is able to "tell" the host that there is a delay, and the host can compensate by "nudging" things forward a bit.
If the latency is very low, the CPU utilisation of Water Glass will become erratic. This is easily explained: for most of the time (perhaps four out of every five "little" buffers passed in) the plugin is doing very little work, just "passing on" data that it has already processed. But then once a buffer has accumulated, it does a processing operation on the accumulated "big" chunk. If this uneven CPU usage causes problems, you may need to reduce your latency settings. For most apps this is done with an audio settings dialog, but for Steinberg products like Cubase and Wavelab, you have to go to your soundcard's ASIO settings dialog.
All content and software Copyright 2007 Trevor Magnusson