Amps without standby question (s)...

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Riscchip, Sep 9, 2005.


  1. Riscchip

    Riscchip Member

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    I've read in the past it's better to switch your amp to standby if you are planning on coming back to it within an hour or so, rather than turning it off. Any truth to that? If so, what about an amp with no standby...is it putting lots of wear and tear on the amp to turn it on and off a bunch? I play 3-4 hours in the evening with 20-40 mintue breaks in between.

    How hard is it to mod an amp with no standby to have one?

    Thanks!
     
  2. R3deemed

    R3deemed Member

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    Is it a tube amp?

    Tube amps have stand-by switches. Solid state amps don't.
     
  3. Riscchip

    Riscchip Member

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    Oops...should have specified. Yes, we're talking tube amps without standby, not SS amps.
     
  4. jockman

    jockman Member

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    My Park 20w does not have a standby switch, but, it seems to take a minute or so before the sound comes through.
    I couldn't say if it has an adverse effect on the valves, seems ok to me.

    Jon
     
  5. VacuumVoodoo

    VacuumVoodoo Member

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    A standby switch is not really needed in a tube amp with tube rectifier. It takes a while for the rectifier tube to heat up to full emission temperature and since all other tubes also take a while to heat up nothing drastic or directly damaging will happen.

    It may have a little effect on the tubes' lifetime since initially the tubes will be working underheated which may cause cathode stripping and gas contamination in the long run.

    The situation is different with solid state rectifiers, these start conducting fully as soon as power is switched on and full plate voltage is applied directly to cold tubes. This can cause more severe cathode stripping and such amps should have a standby switch.

    Use the standby switch, if there is one, on first power on and leave the amp on for the duration of use. No real need to put it in standby mode during intermissions etc. IMHO.

    Leave the standby switch on and turn off power, this way electrolytic caps will discharge nicely.
     
  6. jetlag

    jetlag Member

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    In my amps w/o standby switches ( EGtweed deluxe, small gibsons) they use a 5Y3. The 5Y3 will still send a jolt since it's directly heated. So I use a special industrial version of the 5Y3 that is indirectly heated = slow warmup. Some amps have internal circuitry (I think a varistor) that slows the warmup as well. Anyway, I sought out and found that 5Y3 just a cheap insurance for all the nice RCA 6V6's I run in those amps - a means to extend their life.
     
  7. Twangmaster

    Twangmaster Member

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    hmmm, interesting thought. I'd always heard that you should put the amp on standby for about 30 seconds before powering down. But your observation does make sense! Thanks!
     
  8. Riscchip

    Riscchip Member

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    Thanks for the info guys! I didn't know that about rectifiers. So I gather there is really no point in a standby mod for a tube rectified amp?

    Thanks again!
     
  9. hasserl

    hasserl Member

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    The problem of cathode stripping is greatly overstated in the guitar world. Tube PA amps and ham radio equipment operated for decades on the same set of tubes, with no standby switches. The old guys that worked on that equipment would laugh at how anal us guitarists get with things like this.
     
  10. drbob1

    drbob1 Silver Supporting Member

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    YMMV, but amps that use an indirectly heated rectifier (like the GZ34) have no need at all. Amps with a rectifier that conducts immediately (like the 5Y3) may get slightly more tube wear than if they had a standby switch. It's not a super hard mod to do, so if you're running NOS tubes in an amp you don't mind modding-go for it. Modern tubes, expensive amp-don't bother...
     
  11. rpavich

    rpavich Member

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    Uh-Oh,

    My Ghia has no standby and uses a 5Y3 rect tube...whoops...

    Now you've got me wondering..

    bob :(
     
  12. VacuumVoodoo

    VacuumVoodoo Member

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    The key word is "heated", whether directly or indirectly the rectifier tube still needs some time untill it is fully conducting.
    Directly heated tube will reach nominal working temperature faster but not that much faster as to cause any significant concern.

    Also, as hasserl pointed out, cathode stripping is in most cases a negligible concern. Most probably your power tubes will sooner fail due to other mechanisms than cathode stripping.
    We are not dealing with high power radio transmitters where this would cause a directly audible performance degradation at the recieving end i.e. in your radio receiver.
     
  13. jockman

    jockman Member

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    As I said, I don't have a standby switch, but my amp does not have a valve rectifier either.

    Jon
     
  14. noctilux1

    noctilux1 Member

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    This has been a nagging question in my head for years. I have an old Orange OR120 Overdrive 2x12 combo, no standby. I'm quite set against any mods to equipment but, with so much juice hitting this 120 watt head I've wondered, is this hurting the amp? I've owned the amp since 1980. It still sounds great. Not sure if I will ever put a standby in there or not.
     
  15. hasserl

    hasserl Member

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    You've owned the amp since 1980 and it still sounds great. Obviously it is not being hurt operating the way it is. Don't sweat it and don't dick with it, just enjoy it.
     
  16. Jon Silberman

    Jon Silberman 10Q Jerry & Dickey Gold Supporting Member

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    My Reverend Hellhound lacks a standby switch.
     

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