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HELP! my amp shut off by itself

Discussion in 'Amps and Cabs [BG]' started by jobu3, Jul 28, 2002.


  1. jobu3

    jobu3 Artist formerly known as Big Joe

    Feb 17, 2002
    Mountain Top, PA
    tonight i was playing my swr bass 350 at the volume i always do. no clip led light or anything. my amp wasn't overly hot, it was pretty darn warm but not the searing heat it usually gets after a set. well the amp just shut off mid song. i checked the amp and speaker fuses but they were intact. nothing else in my rack shut off. it wouldn't turn back on for at least 15 minutes and then finally it did. it was really noisy for a while too. i had the levels i was playing at when it shut down and banged the bejesus out of the strings and there was still no clip led flashing. i know it wasn't the fuses, i know it wasn't clipping, and it wasn't overheating i don't think. could it be the preamp tube going? i don't know... any thought or ideas would be greatly appreciated, thanks!
     
  2. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    God is crying, probably because of something you did.
     
  3. Try replacing the tube. Take it to a tech, try the amp again and see if it does it a second time then take it to the tech.

    :D:D

    Merls
     
  4. StrudelBass

    StrudelBass

    Jul 6, 2002
    California
    Plug the amp back into the wall! :D :rolleyes:
     
  5. jobu3

    jobu3 Artist formerly known as Big Joe

    Feb 17, 2002
    Mountain Top, PA
    i will try a new tube. munji: y'know i was just questioning the existence of god when it happened and now i know He must exist! thank you for enlightening me! and yes He probably is punishing me for not buying eden. and strude1: that was the first thing that i checked, it has come out from my power conditioner before from the vibrations. thanks guys!
     
  6. jobu3

    jobu3 Artist formerly known as Big Joe

    Feb 17, 2002
    Mountain Top, PA
    this is the last time i ever buy swr! even if this is minor, they never write back when i've asked them questions...
     
  7. jasonbraatz

    jasonbraatz

    Oct 18, 2000
    Oakland, CA
    don't e-mail them! call them!!!


    not all companies utilize email as their #1 form of communication. call them, they're very nice and helpful.
     
  8. FunkySpoo

    FunkySpoo Supporting Member

    Feb 6, 2002
    Yeah definetly call them. I just did and they were very heplful and friendly. I wasn't put on hold or anything.
     
  9. jobu3

    jobu3 Artist formerly known as Big Joe

    Feb 17, 2002
    Mountain Top, PA
    i just called, i talked to him (very friendly by the way) and he said it turned itself off because i was driving it too hard. he said that you should not turn the gain or volume up past 12:00. this now makes my amp garbage... i usually run the volume up to 3:00 and the gain up to 12:00. it has never clipped but this is still too high? i guess he knows what he's talking about but this sucks arse!:mad:
     
  10. jasonbraatz

    jasonbraatz

    Oct 18, 2000
    Oakland, CA
    yeah that's in definite clip territory. i used to run my bass 350 even harder (pregain 3:00, master volume almost at 100%) with a 2 ohm load!!! surprisingly it never shut down, but i did manage to take out all my speakers :(



    it's a sign you need a more powerful amp. you could get a power amp and use your bass 350 as a preamp...that wouldn't be too expensive.
     
  11. jobu3

    jobu3 Artist formerly known as Big Joe

    Feb 17, 2002
    Mountain Top, PA
    yeah, but i don't like it that much so i might just trade it. i don't know. it was supposed to last me for another year at least. i might just get a power amp and a preamp, i have to think about it...:(
     
  12. Hmmm, the only time I have EVER had a problem with my 350 is when there were power source probs.

    I have run the gain up to about 5 but normally keep it at 3-4. The master has only been up to 7 or so (about 3 o'clock). I have changed the tube once trying to get better tone, and that's it.

    I have been playing like 44 weekends a year, both Fri and Sat nights, for about 6 years with this head and it has been beautiful, and personally I like it and hated the eden I got stuck playin all night once.

    But that is the tone that I am after so, to each his own.
     
  13. FunkySpoo

    FunkySpoo Supporting Member

    Feb 6, 2002
    That's really odd because in the amp manual it says to turn the gain up till the clip light barely lights up on your loudest notes then turn the master volume up to the desired level. This is supposed to give the best signal to noise ratio. I have my gain turned up to the 2 o'clock position and my master, on my loudest gigs at 2 o,clock also and never have had a problem. So maybe if you turn up the gain and back off on the master it might help.
     
  14. I only just upgraded my SWR Bass 350. I used to run mine really hard, with the gain at about 2 o'clock so that the preamp clipped when I whacked the B. I used to drive the power stage to about 3 o'clock and I had no problems.

    The fact that the amp shut down and the noise both point to a duff preamp valve that's overheating and has become microphonic. Buy a new one - they're not expensive. Electro Harmonix 12AX7WX (I think) sound good and aren't a lot.
     
  15. jobu3

    jobu3 Artist formerly known as Big Joe

    Feb 17, 2002
    Mountain Top, PA
    "That's really odd because in the amp manual it says to turn the gain up till the clip light barely lights up on your loudest notes then turn the master volume up to the desired level."

    Yeah thats what i thought too and i never even ran it up that high. i mentioned it to him and he said that is still running the amp too hard. he also said that you can't run them at 2 ohms either. he said something about capabilities not recommended to be used there though... i just don't get why they say one thing and then another. i chose this amp because i was able to run a 2 ohm load. or so i thought. i know with aguilar it is perfectly safe to run down to 2. i still think i'm just gonna get rid of it.
     
  16. FunkySpoo

    FunkySpoo Supporting Member

    Feb 6, 2002
    Yeah I think advertising a 2 ohm load is kind of a stretch, at best. Well if you're considering the Aguilar then I think it's a no brainer. Aguilar all the way.
     
  17. jobu3

    jobu3 Artist formerly known as Big Joe

    Feb 17, 2002
    Mountain Top, PA
    i plan on getting an all ag rig but not for a year...
    db 210 (hopefully they have a 4 ohm version by then), db 212, and the 750 head. but as i said, not for another year.:(
     
  18. According to the manual (and common sense) you're meant to increase the gain while playing your bass hard-out until the gain LED starts to indicate clipping, and then back off a touch. For someone like me with a relatively soft playing style the gain knob generally sits up around 1 to 3 o'clock (more to 3 o'clock since re-EQing at a flatter setting). I know the guy works for SWR, but is he sure he knows what he's talking about?!

    Hamish :confused: