Possible amp / cab / power issue (need suggestions)

Discussion in 'Live Sound [BG]' started by Dr3thepooner, Feb 1, 2014.

  1. Hey All!

    So very strange thing happened yesterday.
    We usually practice in a very small space - Drums, Guitar, Bass, Vocals.
    Yesterday was the exception, we had extra guitar player with crap load of pedals and 30watt head, nothing unusual, but his was the only major change to our set up.

    I had plugged in as usual in a power bar (cheap) - I run passive bass - > 4 pedals - >kg mb800 - > neo410 8ohm.

    Started warming up, and all of a sudden my sound level dropped a lot! and i started hearing a lot of braking up and distortion.

    First thought blown speakers (cab and head are 3 month old with very little use - usually volume is not over 9 o'clock with drive at noon, that little head is LOUD!).
    I powered everything down, disconnected pedal board - bass straight into the head - same. Bummer. Power down, connected head into different power outlet - it in started working! everything crystal clear and punchy for about 10min. Then same again.
    That night i kind of gave up, but weird thing i had noticed when 3 of us - guitar , guitar , bass would start to play at the same time, sound would clean up... and it would sound ok. I count find any logical pattern to this issue. It would come and go, so not the cab i assume...

    As soon as I got home - set everything up, except pedals - played at a low volume for about 30 min - everything is perfect! Even played thru head on its own (solid state is fine that way with headphones - perfect)

    What might that have been??? Bad power? ... I know the other band was rehearsing in the room next to us, but this never happened. I am just afraid if this will happen at the venue /gig. Any one would recommend power conditioner?
    I dont have a rack, so the floor one i guess?

    Thanks lads!
  2. ggunn


    Aug 30, 2006
    Austin, TX
    Cold solder joint in the head exacerbated by vibration when playing loud? Shorting speaker cable? It's not likely to be a power problem.
  3. I just pushed it pretty hard at home... pretty much same level, even shook the head and moved the cab a little - couldnt get the brake up to happen. Played for about 30 min.

    I guess I will have to go back to the practice space on my own and see what happens.
  4. ggunn


    Aug 30, 2006
    Austin, TX
    Still, a "power conditioner" won't help you. If you have a voltmeter, stick the leads in another outlet on the power strip while you are playing, and look at the voltage if you can make the problem happen again. It might be low voltage, but the voltage would have to be significantly lower to cause that problem.

    At any rate, if it is a power problem, it's most likely a wiring problem, not something that a power conditioner would solve. They don't do a whole lot.

    One thing that is always in my kit is one of those power testers with the LED's on it. The will show you if there is an open neutral, open ground, hot-neutral reverse, that sort of thing. Some of these conditions are dangerous.

    Good luck.
  5. Thanks dude!

    This is helpful.
    I am taking the whole rig to the studio tomorrow, will push it hard, see what happens.
    I called my music store and all my stuff is still covered under the warranty, I will be stopping by there too for a check up.
  6. Just a status update, for some one with unlikely same issue.

    So I went to 2 different places to test my stuff out : Studio and a friend's house where I could crank my **** up.

    Everything works perfect! ... 1 hour jam at the studio, not an issue, 2 hour jam at a friends place.. way louder than I used to turn it up, at 11 o'clock could barely hear acoustic drum set - ripped it, no problem. (BTW i just realized how awesome this head sounds when its driven harder ... dude.)

    I did purchase surge protector and power conditioner, so will take it to our jam space where the issue happened and see whats up.

    But it was definitely having to do with not enough juice for my amp. So never say never.
    If it was bad soldering or blown speaker, i dont see how it fixed itself.
  7. ggunn


    Aug 30, 2006
    Austin, TX
    If it's a low voltage problem, neither of those will have any effect on it.