1. Welcome to TalkBass, the Premier Bass Player Community and Information Source. Register a FREE Account to post and unlock tons of features!

Changing impedance with amp on

Discussion in 'Amps [BG]' started by JonnyAngle, Jan 25, 2013.


  1. JonnyAngle

    JonnyAngle Dropping Acid Pedal Etching Supporting Member

    Nov 24, 2008
    Maple Grove, MN
    Disclosures:
    Dropping Acid Pedal Etching
    Is it ok to unplug speaker cabs while the amp is on? I have a GK mb500
     
  2. Primakurtz

    Primakurtz Registered Nihilist Supporting Member

    Nov 23, 2011
    Denver, Colorado
    For your amp, yes. No problem.
     
  3. TalkBass Friendly Advertisement


    to hide this ad and more.
  4. dincz

    dincz

    Sep 25, 2010
    Czech Republic
    Does your cab use a 1/4" jack or a speakon? A jack plug might short momentarily as you're pulling it out.
     
  5. B-string

    B-string Gold Supporting Member

    Yes this is important! 1/4" CAN damage your amp easily!!! I still would not be comfortable with a speakon, but chances are slim with a speakon.
     
  6. Dave W

    Dave W Supporting Member

    Mar 1, 2007
    White Plains
    I'd just turn it off, it takes no time at all.
     
  7. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Disclosures:
    Endorsing: Ampeg Amps
    Ya, what's the point of leaving it on? Takes 1 second to turn a switch.
     
  8. JonnyAngle

    JonnyAngle Dropping Acid Pedal Etching Supporting Member

    Nov 24, 2008
    Maple Grove, MN
    Disclosures:
    Dropping Acid Pedal Etching
    I use the 1/4". I'd like to a/b a 16 ohm 210 and an 8 ohm 410(2-210s)
     
  9. B-string

    B-string Gold Supporting Member

    USE THE POWER SWITCH when disconnecting or connecting cabs! Otherwise A/B'ing new amp heads may result. Just don't touch any other controls and your A/B will be successful. :)
     
  10. 1958Bassman

    1958Bassman

    Oct 20, 2007
    You'd be better off turning it off. The tip can short to the sleeve when the plug comes out and it doesn't take long to toast an amp with a dead short.
     
  11. ThisBass

    ThisBass

    Aug 29, 2012
    Germany
    If the amp is silent which means no signal then the situation equals off state.
     
  12. B-string

    B-string Gold Supporting Member

    Are you positive with this on a Class D bootstrap output? At least enough to pay for damages?
     
  13. dincz

    dincz

    Sep 25, 2010
    Czech Republic
    Same situation - no signal no output. If you can be sure a burst of noise or something is not going to come through just as you're pulling the plug then OK. To be safer, turn down the master. But then why not just switch off?
     
  14. spankdaplank

    spankdaplank

    Jan 19, 2003
    Philippines
    I killed a Yamaha BBT 500H doing just that. I thought it was in the O-F-F position but it wasn't. A tiny spark at the jack when I pulled out the 1/4" phone plug was all it took.
     
  15. Cadfael

    Cadfael

    Jan 4, 2013
    Germany, EU
    Pulling out a 1/4" jack can produce a short cut "ZERO Ohms" for a moment.

    Indefinite impedance is no problem vor a transistor power amp - but zero ohms will damage it.

    A Speakon can't produce a short cut while unplugging. So it's no problem with a speakon, but a 1/4" MIGHT cause problems.

    Changing the impedance while the amp is on may not be bad for the amp - but it is surely not good. So, switch it off ...
     



Share This Page