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Powering DOWN a tube amp.....

Discussion in 'Amps and Cabs [BG]' started by Rockbobmel, Jan 2, 2005.

  1. Should the power switch be shut down, then the standby, or the other way around???
  2. Ralphdaddy

    Ralphdaddy Supporting Member

    Nov 6, 2003
    Chicago, Illinois
    I always put mine in standby first, let it cool down for 30 seconds to a minute then turn off the main power switch. So far I've had no problems with my amp going this route but you MUST remember to turn off the main power... I once left my Traynor running in standby mode for a full 24 hours because I forgot to turn it off! Nothing bad seems to have occurred but it worried me anyways.
  3. Trevorus


    Oct 18, 2002
    Urbana, IL
    I have done this same thing witht he same outcome, but it is kinda scary to know the tubes were just sitting and cooking for that long. I generally just turn off both at once, and have never had a problem.
  4. IvanMike

    IvanMike Player Characters fear me... Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    "............standing by................"
  5. Rock City

    Rock City

    Apr 8, 2001
    You can just shut off the main power. There is no reason to go to standy first. The only reason for starting the amp in standby is to let the heaters warm up the tube. Electrons cannot flow in a vacuum until warm. It also doesn't do the tubes any good to slam them with B+ until they're warmed up.
  6. Ralphdaddy

    Ralphdaddy Supporting Member

    Nov 6, 2003
    Chicago, Illinois
    Interesting... good deal, saves me from repeating the same dumb mistake! Thanks!
  7. Lockout


    Dec 24, 2002
    I tend to put it in standby first before turning the power off, if only to make sure that I don't forget to set the switch to standby before the next time I turn the amp on.

    GIBSONGEEK, is there any possible harm in doing it this way, or is it fine to put it in standby before turning the power off?
  8. For years I would go into standby and then kill the power. Never caused a problem.

    But about a year ago I started just killing the power first. Still no problems.

    I'm sticking with my current way of doing things because of the advice I received from several tube techs. I think the school of thought involves fully draining the capacitors so that they do not develop a "memory" of being always charged to a certain degree. Not fully draining them at shutdown is akin to "short-cycling" a battery which somehow leads to shortening their "potential" life. Or something like that.
  9. Rock City

    Rock City

    Apr 8, 2001
    No harm either way guys. In most amps, leaving the stanby switch on DOES help to drain the caps. They will recover a bit when the switch is shut off again though.
    I've done it both ways for years and never had an issue.
  10. Short-cycling caps? Huh? Horse hockey, IMHO.

    The caps will most likely drain off after you turn the amp off anyways (though I always check to make sure by putting a resistor across the terminals). Even if they don't, so what? Modern electrolytics are reasonably robust, they recover nicely and don't need any special treatment.

    Now if you turn on a vintage amp that's been sitting in the closet for 40 years, you may encounter a problem from the dried-out electrolytics....but that's due to old age, not any "memory".
  11. Waabs

    Waabs Employee, Musical Instrument Retail

    Aug 1, 2004
  12. I usually leave the amp 'running'- standby "off' but it doesn't really matter much either way in most amps. Caps will develop a memory like batteries over time unless the amp has bleeder resistors, but (I've seen filters stay almost fully charged for days after power down.) with modern caps, it doesn't hurt that much, but I like to be extra sure.
  13. I'll take the blame for this. It was my poor attempt at selecting an analogy to describe another's attempt to explain to me the benefit of killing the power first.
    What about before modern electrolytics? Was there any benefit 30 years ago to killing the power first (before standby). If so, maybe what I've been told is a holdover from yesteryear.
  14. Toki


    Dec 25, 2004
    I`ve been using a Fender 135 Bassman from the 70's for a bout 3 yrs now, still with the original tubes in it. It takes about 10 minutes to heat up to optimum and get it's voice. I always turn it on and let it warm up at least 15 minutes before a gig. Afterwards I just shut it down. Never any problems.
    I had used GK's for the last 10 to 12 yrs and decided to go back to Fender tube for the tone. Can`t find any of the original Traynor big heads anymore.