Effect Mode, Reverb, Delay, Chorus, Flanger

VM04 Owner’s manual

7. Effect Mode

The VM04 carries 20 types of internal digital effects. You can also alter their parameter settings in detail. We will discuss the digital effects here. To fully understand their versatile effect functions, we recommend that you listen to the actual sound while reading the explanations below.

The DSP effect section inside the VM04 employs the A.S. P. (Fostex Advanced Signal Processing Technology)*, which is exclusively developed by Fostex, and obtains high quality ambient effects almost equivalent to a professional reverb unit.

*A. S. P. (Fostex Advanced Signal Processing Technology)

The A. S. P. is an exclusive new digital effect processing technology designed by Fostex. This method extracts maximum efficiency from the limited DSP power. It achieves an overwhelmingly high density Early Reflection sound and wonderfully smooth High Dump response through the H. F. A. (Harmonic Feedback Algorithm). Also, it carries out an elaborate reverb simulation with clear sounds through the H. D. L. P. (Hi-Density Logarithmic Processing), which eliminates the mutual interference between the numerous integrated delay modules and reduce the impurity and grit of the sound.

*H. F. A. (Harmonic Feedback Algorithm)

There is one of indispensable elements in the natural echo called “Early Reflection sound”, which is usually sacrificed in commercial reverb products in order to reduce costs. (In practice, the Early Reflection sound means the very first reverberated sound that bounces back from walls, floors and ceilings of concert halls). The entire reverb sound quality depends on this Early Reflection sound and how closely it can resemble the real echo. The H. F. A. is an algorithm that enables the effect unit to reproduce a clear and natural Early Reflection sound by applying an ideal harmonic feedback to each delay module.

*H. D. L. P. (Hi-Density Logarithmic Processing)

The reverb sounds consist of lots of small delay elements combined in a complex way, which are produced by many delay modules inside the effect unit. In order to obtain smooth and comfortable reverb sounds, it is very important to efficiently organize the relationship between each delay module and minimize negative mutual interference.

The H. D. L. P. is a technology which applies efficient logarithmic processing to each delay module, so that they can work in the most efficient way in order to eliminate harmful reverb elements and roughness. This makes it possible to establish high density and transparent sounds.

Before operating the EFFECT MODE, let’s briefly discuss the Reverb, Delay, Chorus and Flanger effect functions which are integrated in the VM04.

Reverb

The Reverb effect consists of various reflection (echo) sounds mixed together. Just as when you clap your hands in a tunnel, for example, you hear the sound lingering after you have stopped clapping your hands. This is the Reverb. The sounds we normally hear in everyday life

are made up of three kinds of sound mixed together: “Direct sound”, “Early Reflection sound” and “Late Reflection sound”. The Direct sound refers to sound which reaches the ears directly from the sound source, as the name suggests. The Early Reflection sound refers to sound which has rebounded off a wall only a few times. And the Late Reflection sound refers to sound which continues rebounding long after the Direct sound has disappeared. Our ears normally hear the Direct sound, Early Reflection sound and Late Reflection sound in that order. The Reverb on the VM04 can be set to the following parameters:

*Reverb Time: Sets the length of time the sound reverberates.

*Pre-Delay Time: Sets the time lapse between the direct sound and the reverb sound.

*High Dump: Sets the decay rate of high frequency reflected sound. The decay rate refers to the amount of time it takes a sound to disappear.

*Early Reflection Balance: Sets the audio level of the Early Reflection sound.

Delay

This is the effect obtained by adding a delayed sound to the original sound. You can obtain a richer sound or completely change the original source sound by using the Delay. The Delay on the VM04 can be set to the following parameters:

*Delay Level: Sets the volume of the Delay sound.

*Delay Time: Sets the time between the original sound and the delay sound.

*Feedback Level: Sets the level of the delay sound to be returned to the delay input.

Chorus

The Chorus is used to widen or thicken the original sound. The Chorus on the VM04 can be set to the following parameters:

*Chorus Level: Sets the volume of the Chorus sound.

*Modulation Rate: Sets the Chorus modulation frequency.

*Depth: Sets the depth of sound available on the Chorus.

Flanger

This is to use to create a sound like a jet airplane taking off or landing. The Flanger on the VM04 can be set to the following parameters:

*Flange Level: Sets the volume of the Flanger sound.

*Modulation Rate: Sets the Flanger modulation frequency.

*Feedback Level: Sets the volume of the Flanger sound feedback.

The type of Effect the VM04 provides can be set individually in the way described above. Some combinations of these are also available. These are explained on the next page.