Trash Triode Usage Notes

These notes will help you get the most out of Trash Triode, the vacuum tube and cheap amp construction kit. DirectX and VST versions are available.

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.

Controls

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.