#1
Few days ago, I went and played bass together with my fellow guitarist for the first time. This was also the first time when I turned my little HBW-20 bass amp (dont laugh, i know it sucks! )to almost max volume and high gain. It started to make an overdriven sound, although i didnt have any effects on.

Can someone explain this in-depth? And what is this phenomenon actually called? I think it has something to do with the pickups capturing the sound of the amp, but im not sure why it makes it sound overdriven. And also, lets say I wanted to play loud, but with a clean sound and the amp still overdrives automatically. Can this overdrive effect be prevented in any way?
#2
It is called breakup, and it usually sounds like crap in smaller solid state amps. If you don't want it to happen, get a bigger, better, and more powerful amp.
#3
You are right: it doesnt sound very good compared to some overdrive pedal for example. Im going to buy a bigger amp as soon as i get enough money, but this current one is good for practicing.

But i would still want some more "technical" explanation about this breakup. anyone have a clue?
#4
i would imagine you are doing the same sort of thing as when an audio file clips. the output is too high for the circuitry or speakers to handle. anything above the level that is set is cut out completly which drastically reduces the detail or quality of the sound. if you look at a sine wave that is just clean followed by a distorted or overdriven sine wave it shows what has happened best imo.
i think thats pretty much right.
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#5
Quote by ShockHazard
You are right: it doesnt sound very good compared to some overdrive pedal for example. Im going to buy a bigger amp as soon as i get enough money, but this current one is good for practicing.

But i would still want some more "technical" explanation about this breakup. anyone have a clue?

I don't know why it happens on solid state amps, but on tube amps it is because the tubes are being driven harder than normal and start to break up and, I believe, clip (explained above), so I imagine the same thing happens to the preamp of a solid state.
#7
My amp settings were about something like following:
(-5 is minimum and 5 is maximum)

Gain: 3
Bass: 2
Mid: -2
Trebble: 2.5
Main volume: 4-5

and from my bass knobs i had tone turned down about 20% and volume at maximum. (Its a squier affinity p-bass btw)
Last edited by ShockHazard at Mar 26, 2012,
#8
Basically, the amplifier is attempting to amplify beyond its maximum voltage.

This clips the peaks of the waveform, creating the nasty distortion sound.
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#9
Quote by Nutter_101
Basically, the amplifier is attempting to amplify beyond its maximum voltage.

This clips the peaks of the waveform, creating the nasty distortion sound.


This^ if you don't know don't guess.

Basically your signal is a sine curve like sideways S when you provide too much power, either by high input signal, turning gain high, using a pedal it takes the curve from the S squaring it (hence the term clipping), which in effect distorts and compresses the signal.

most bass amps are designed to prevent clipping therefore tend to give a pretty piss poor clipping. GK RB 400/ RB 800 are both known for a good growling grind tone though.

Speakers can also be distorted.
#11
Quote by Nutter_101
Basically, the amplifier is attempting to amplify beyond its maximum voltage.

This clips the peaks of the waveform, creating the nasty distortion sound.

Followed by speakers don't like square waves which are created when the output stage distorts whereas the input stage can overdrive as much as you want and the output stage will just see it as a signal like any other.
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