I've got a little Yamaha GA-15 practice amp (a newer model than in some of the instruction manuals available, it has a mids EQ knob as well as treble and bass), which is currently all I have, as I'm not working with a huuuuge budget, and it's all I need at my skill level. Sadly, a few days ago, a problem arose. I had changed few, if any, settings, and suddenly, when I played


After the three open notes, my amp made this very loud humming/deep rumbling sound. This only happens with overdrive (I think). The thing is, before then, with very little difference in settings, this hadn't happened, and when I changed the settings back, it continued. The only way to reduce the volume (as I'm worried about damage to my amp), is to change the "bottom" option on the overdrive/dist section of my Boss ME-50 down a lot, but then I can't always get the sound I'm after.

So, any ideas what's causing this, and how I can fix it/get it fixed?

P.S. I'd ask yamaha, but if anyone can figure out which support section on the yamaha website I should ask at, I'd be surprised, what with all of their amps now being under the Vox label (although I got mine after that occurred, in a package with my pacifica 112), my Yamaha amp doesn't fit into the available categories for service.

(By the way, sorry about any spelling mistakes, it's late, and I'm very tired.)
Last edited by Archdoom at Mar 7, 2009,
Is your cable going bad? Try a different cable and report back.
If you start a reply with: I have never played one but I have heard good things about it! Your opinion is invalid.
An interesting idea, I mean, I've broken cheap ones before, but that just killed my sound, but I'm using decent cables now, so I dunno. Sadly, cannot test till tomorrow (Australian time), because Everywhere in the house I could play it right now has someone asleep nearby, but thanks, I hadn't thought of that. Will check tomorrow.

Although, my cables are pretty decent, and nothing else has suffered, it's just that, so I dunno, but I am not an expert, so I dunno whether or not that means anything.

Any other ideas and such from anyone are still good too
Last edited by Archdoom at Mar 7, 2009,
Nope, not the cables. Swapped the two cables in use with two others, the same thing occurs. Any more ideas?

Oh, I just found, it actually occurs when I play the 3 heaviest strings muted on the 1st fret, and also occurs in DADGBE tuning

i.e. D|-x
Played with the mutes on the first fret, causes the large humming/thump, after the normal thump sound you get from playing that.

The thumping is lessened when I lower the bottom or distortion settings on the distortion pedal of my settings, but I like to keep those both rather high, so it's quite problematic. It's not like I've changed my settings there from before it occurred.


EDIT: I think it's the overdrive system in my Boss ME-50, cos if I use the crap amp OD, no THUMP. On the upside, I just bought a fuzz factory, so I won't be using the BOSSes Distortion any more, and if its from going through the boss, I might have to OD it after the boss, which I know won't sound great, but ah well, I'm crappy anyway.
Last edited by Archdoom at Mar 9, 2009,