Regarding sustained notes on big amps

[lexxmexx]

I play my bass on my little practice amp most of the time so I don't have much knowledge about the larger amps. My question is when I play it on these large amps, I tend to notice something strange.

The long sustained notes will not fade away but instead, will tend to get louder gradually and become distorted eventually. Sometimes, when I set the amp volume a little louder, the notes will somehow get messed up, like semitones will not be distinguishable, eg. C and C# sounded almost the same. I had checked the tunings and they were fine. This only happens on the larger amps, not on my practice amp though. Why is this so?

 

[Blues Cat]

What bigger amp are you talking about?

Sounds like you're describing a broken amp or worn out speakers.

 

[ilovethesechord]

Hmmm.. do your strings get louder because you play too hard?

Maybe your action is too low. As your strings vibrate, that distortion might be strings rattling.

I don't know. I'm clueless.

 

[xampworshipx]

if it's gradual then what you're probably getting is the same decay on your bass followed by feedback (which usually picks up on harmonics and semitones)

 

[jady]

You are probably not hearing much of the fundamental on your practice amp but the 1st order harmonic.

Hearing a huge fundamental takes some getting used to and can be a bit disorienting.

 

[Jim Carr]

I play my bass on my little practice amp most of the time so I don't have much knowledge about the larger amps. My question is when I play it on these large amps, I tend to notice something strange.

The long sustained notes will not fade away but instead, will tend to get louder gradually and become distorted eventually. Sometimes, when I set the amp volume a little louder, the notes will somehow get messed up, like semitones will not be distinguishable, eg. C and C# sounded almost the same. I had checked the tunings and they were fine. This only happens on the larger amps, not on my practice amp though. Why is this so?

A larger louder amp can put out enough sound to cause the strings to vibrate. This is then in turn amplified, which will further cause the strings to vibrate, which will further cause the strings to vibrate, which will further cause the strings to vibrate, which will further cause the strings to vibrate...BOOM! Magic Smoke escapes....

Seriously, though, it sounds like you are getting some feedback. Just damp the string lightly with your fretting hand.

 

[lexxmexx]

I had experienced this on a couple of Marshall amps (not sure about the exact model though) at the studios I had been to. The explanation about the feedback chain reaction sounds logical as I had been standing right infront of the amps with both master volume and gain controls set at at 2 o'clock position.

Just damp the string lightly with your fretting hand.

Did you mean muting the unplayed strings while sustaining the one being played?

I like your description about the chain reaction thingy, can I use it as my signature?