My amp is acting weird.

WilliamSandoval · #1 01-11-2012, 05:34 PM

I have an Acoustic B200 combo 115 w/ tweeter and port for small gigs.

All of a sudden whenever I use a pick or slap on the E string, it sounds like it's being played through a phaser. I've lowered the pick up height in case it was too close, but that didn't fix it. I've adjusted the gain and volume, but that didn't fix it.

What's the problem guys? I'm not running any effects, so...

BassmanPaul · #2 01-11-2012, 05:42 PM

It has a problem so it's tech time.

will33 · #3 01-11-2012, 05:50 PM

Yep, that's an amplifier problem. A bad speaker won't sound like a "phaser". I'd watch how deep you go in this. A bench fee to see what the problem is, what it might cost to fix is OK. If it's not a cheap fix, just look for another amp. Those Acoustics are budget gear, it wouldn't take too long for the repair bill to exceed the amps value.

WilliamSandoval · #4 01-11-2012, 05:58 PM

Wow. I de-tuned the E string, tuned it again, and no more phaser effect. Weird.

will33 · #5 01-11-2012, 06:28 PM

Quote:

Originally Posted by WilliamSandoval

Wow. I de-tuned the E string, tuned it again, and no more phaser effect. Weird.

It's a problem with your bass. See that the string is seated properly in the nut slot and bridge saddle and that either hasn't worn too big letting the string vibrate around in there.

MIJ-VI · #6 01-11-2012, 06:39 PM

+1 After my bass guitar has been tuned to pitch with new strings I always put a finger on the headstock and fretboard sides of a freshly installed E string's nut slot and press down a bit to ensure the string exits the fretboard side of the slot cleanly.

Schlyder · #7 01-11-2012, 06:47 PM

Active pickups.. dying battery?

WilliamSandoval · #8 01-11-2012, 07:28 PM

Quote:

Originally Posted by Schlyder

Active pickups.. dying battery?

Passive pickups.. no battery

ACalbass · #9 01-11-2012, 08:08 PM

I think the string is too close to the fret and when it vibrates,first it touches it,then when it vibrates less it don't.
This can cause some strange sound through the pickups,as a phaser.
See if the fretboard is straight,might be twisted somewhere.

SurferJoe46 · #10 01-11-2012, 08:37 PM

Twisted string - loosening it let it untwist somewhat.

You've solved your own problem.

WilliamSandoval · #11 01-11-2012, 09:14 PM

Quote:

Originally Posted by SurferJoe46

Twisted string - loosening it let it untwist somewhat.

You've solved your own problem.

It's actually a thing?

jmercer91 · #12 01-11-2012, 09:28 PM

Quote:

Originally Posted by WilliamSandoval

It's actually a thing?

Yep

Sundogue · #13 01-12-2012, 07:05 AM

Quote:

Originally Posted by SurferJoe46

Twisted string - loosening it let it untwist somewhat.

You've solved your own problem.

Most definitely the problem. Do you (the OP) "wrap" the end of the strings around the tuning peg or do you let the tuner pull them around the shaft?

When stringing up a bass, you absolutely must NOT wrap the end of the string around the tuning post by hand, especially if the ball end is seated in the bridge already. This causes the string to "twist" and it is exactly this twisting that causes a "chorus" or "flanger" effect.

Because the OP downtuned, the string's ball end let loose, untwisted, and then when he tuned back up the twist (and therefore the "flange" effect) went away. Very common problem.

Funny how such a simple task as stringing a bass can have such a big affect on the sound.

will33 · #14 01-12-2012, 10:52 AM

Quote:

Originally Posted by Sundogue

Most definitely the problem. Do you (the OP) "wrap" the end of the strings around the tuning peg or do you let the tuner pull them around the shaft?

When stringing up a bass, you absolutely must NOT wrap the end of the string around the tuning post by hand, especially if the ball end is seated in the bridge already. This causes the string to "twist" and it is exactly this twisting that causes a "chorus" or "flanger" effect.

Because the OP downtuned, the string's ball end let loose, untwisted, and then when he tuned back up the twist (and therefore the "flange" effect) went away. Very common problem.

Funny how such a simple task as stringing a bass can have such a big affect on the sound.

+1

I had this happen to me once and it baffled me for the longest time trying to figure out what was wrong with my stuff. First I thought I was digging in too hard with some buzzy preamp tube grit settings, then I thought the tube may be going bad, then it had me taking stuff apart checking wiring and if speakers were tight, looking for tears in the cones, etc. Turns out it was just the damn string the whole time.