OD vs Distortion

[eSGEe]

 

[smitty_p]

so a compression pedal can deliver distortion and a distortion pedal compresses??!?!
you can see why a dont own but 2 pedals with that logic eh?

whats an echo ----reverse time?

First, it’s important to define terms. Distortion and compression are electronically different things, though distortion can have the audible effect of compression, even though that is not what it is intending to do.

With compression, you are limiting dynamic range. A threshold setting determines the peak level of the waveform. Any signal level that is less than that threshold is not altered. However, any level that exceeds the threshold is electronically attenuated to bring those peaks back down to the threshold setting. The limited dynamic range produces a more smooth, even waveform that is good for those singing solos.

Distortion (at least for our purposes) is a clipping of the signal. Clipping results from a signal level that exceeds the ability of the circuit to cleanly process the signal. Thus, the peaks are clipped off, not merely reduced in amplitude as is done with compression. This clipping is what makes the grinding distortion sound. In just about any audio signal except for electric guitars, clipping a signal is a bad thing.

The reason distortion also creates a compression effect is that clipping the peaks results in less dynamic range between the high and low amplitude parts of the waveform, as also results from compression. The main difference is that in distortion/overdrive the peaks are just clipped off. In downward compression, the peaks undergo a controlled attenuation. Now, this attenuation will somewhat alter the shape of the peak parts of the waveform, because it is being squeezed. Extreme compression will result in a distorted sound.

So, there is somewhat of an interrelationship. Distortion will also have a “compression” effect and excessive compression can sound distorted.

Now, to be electronically accurate, any unintended alteration of a signal is “distortion”. But, again, for our purposes we are referring to the clipping that results from overdriving some circuit element, such as tubes or transistors.