3. Parameter Reference

3.8. EFFECT

effect section

  1. Mix
  2. Time
  3. Diffusion
  4. Feedback
  5. Drive
  6. LowCut
  7. HighCut
  8. Speed
  9. Depth

The effect section adds effects to the amplifier signal and outputs to the host application.

The diagram of the effect section is shown below.

effect block diagram

Is is generally called a stereo ping-pong delay. But the overdrive and low/highcut filters are added. It can be used for wide variety of the effect applications as follows.

They are explained at the end of this chapter.

The effect section is much more efficient for the CPU consumption than other sections. Other sections do polyphonic processes for each voices. But the effect section mixes down voices to one signal first and process it. As a result, CPU consumption for the effect unit is low.

3.8.1. Mix

Sets the mixing ratio of the effect sound and the dry sound.

This parameter is also an effect on/off switch. Setting the effect mix level to 0%, the effect process is bypassed.

3.8.2. Time

Sets the delay time.

3.8.3. Diffusion

Sets the time difference between left and right channels.

Putting the time dirrefence to L/R delays, the stereo spread is added to the sound. Adding the diffusion with the modulation and feedback diffuses the effect sound.

3.8.4. Feedback

Set the feedback amount.

The feedback can be set to the both positive and negative directions. Setting the feedback to the negative direction, the feedback signal is inverted and added to the effect input.

3.8.5. Drive

Sets the overdrive amount.

3.8.6. LowCut

Sets the the frequency of the low cut filter.

3.8.7. HighCut

Sets the the frequency of the high cut filter.

3.8.8. Speed

Sets the modulation speed of the delay time.

It specifies the frequency of the sine wave used for the delay time modulation.

3.8.9. Depth

Sets the modulation depth of the delay time.

Adding the modulation to the delay time, the output pitch is changed. It can be set from 0%(nothing) to 100%(whole tone).

Example: Chorus

An example setting for the chorus effect is shown below. Adding small delay time and adding modulation makes the small pitch change. Mixing the delay signal and the original signal, the chorus effect is obtained.

Mix65%  
Time0.02sec Diffusion0%
Feedback0% Drive1%
LowCut20Hz HighCut22000Hz
Speed0.2Hz Depth10%

Example: Flanger

Flanger is a variation of chorus. Although they are similar as setting, the effects are very different. Setting the delay time fewer than chorus, the original signal interferes with the delay signal. In addition, adding feedback emphasizes the interference. The example below looks nearly the same as chorus except setting the delay time to 1/10 and adding feedback. But it sounds very different. Adding the feedback to the negative is another idea and sounds slightly different.

Mix50%  
Time0.002sec Diffusion0%
Feedback+80% Drive1%
LowCut20Hz HighCut22000Hz
Speed0.2Hz Depth10%

Example: Reverb

Reverb simulates the reverberation of the room, hall or so on. A sample setting is shown bellow. The delay time is proportional to the room size. As the speed of sound is 330-340 meter/sec (depend on the room temperature), 0.1 second means about 34 meter. Considering go and back, it represents a 17 meter room. The reflection amount is specified with the feedback amount. The reflection is not uniform and diffused by time. It is simulated with adding diffusion. The sound is absorbed to walls. The absorption amount is dependent on the frequency and typically high frequency sounds are absorbed faster than low frequency. It can be simulated with using the high cut filter.

Mix30%  
Time0.1sec Diffusion10%
Feedback+80% Drive1%
LowCut100Hz HighCut2000Hz
Speed0.2Hz Depth0%

However, the real reverberation is a complex process. It is difficult to simulate the real reverberation well with this effect section. If you want a high quality reverb effect, you can use another reverb plugin.

Example: Modulation Delay

The next example is a space modulation delay effect. Comparing to the reverb, the reverb spreads the sounds naturally and the following setting spreads the sounds artificially. Setting the delay time long and adding the feedback, the sound refrains with decay like echoes. Adding diffusion and modulation, the echo sounds spread and diffuse with time.

Mix40%  
Time0.35sec Diffusion25%
Feedback+80% Drive100%
LowCut100Hz HighCut5000Hz
Speed0.5Hz Depth10%

Example: Overdrive

The last example is an overdrive effect. Setting the mix level to 100% and increasing the drive amount distorts the input. But more interesting effects can be obtained with the feedback and filters.

An example setting is shown below. Setting the short delay time and adding the feedback is a crucial point. With this setting, the distorted sound goes and backs inside the loop. The sound character can be modified with lowcut and highcut filters. Increasing the feedback, the loop begins to oscillate by itself (like a feedback with an electric guitar and a guitar amplifier). Furthermore, moving the delay time changes the self oscillation frequency. You can try with various settings.

Mix100%  
Time0.005sec Diffusion0%
Feedback+8% Drive800%
LowCut200Hz HighCut4000Hz
Speed1Hz Depth0%