SWR rig woes

Discussion in 'Amps and Cabs [BG]' started by nad, Jan 24, 2006.

  1. nad

    nad 60 Cycle Humdinger

    Sep 22, 2005
    Hello, I have an SWR 350x and Goliath III 4x10 4-ohm cab, purchased a little over 3 years ago (pre-Fender buyout). Other than not giving me quite enough volume sometimes, it's been a great rig until recently!

    I'm getting a bit of high pitched distortion on louder notes, that is definitely louder with the tweeter attenuator cranked, but doesn't go away with the tweeter removed so I know that didn't blow. Replaced the preamp tube, no difference. Seems to go away when the amp has been on for more than 10 minutes or so, so I'm thinking it's the head. I'm also getting an occasional volume drop which seems to be linked to the distortion. Also when I plug into the Passive jack, or don't have anything plugged in at all, there is a noticeable buzz. When I plug into the Passive/Active jack, the buzz disappears. I don't know if this is related or not.

    Won't get a chance to try the head with a different cab (and vice versa) until this weekend. Any help is much appreciated!

  2. nad

    nad 60 Cycle Humdinger

    Sep 22, 2005
    If nobody replies I'm just going to sell all this crap and buy a Schroeder and Thunderfunk rig. If that is okay, please give me absolutely no sign. :p
  3. syciprider

    syciprider Banned

    May 27, 2005
    Inland Empire
    How much do you want for the cab?:p
  4. nad

    nad 60 Cycle Humdinger

    Sep 22, 2005
    If you're serious, PM me and we can work something out. I didn't mean for this to turn into a spam thread, apologies to the powers that be! :D
  5. FireBug


    Sep 18, 2005
    What model tube did you replace it with? SWR heads are picky about tubes. Especially Russian ones.
  6. nad

    nad 60 Cycle Humdinger

    Sep 22, 2005
    Tried a JJ and an Electro Harmonix, 12AX7. Amp makes the same ill noise with either one.
  7. Fred312b

    Fred312b What if I want to play jazz precisely? Supporting Member

    Apr 23, 2002
    Chicago, IL
    sounds like a short of some kind... sounds like a trip to the amp doc is in order... and not to nitpick, but aren't the x series amps post-fender?
  8. Ian Perge

    Ian Perge Supporting Member

    May 11, 2001
    Evansville, Indiana
    SWR first upgraded their mono heads with the 750X at Summer NAMM 2002.
  9. jgsbass


    May 28, 2003
    Floral Park, NY
    Sounds like a bad solder joint or a component not solidly attached to the circuit board. Did the amp drop? My 350x went one year 'til it needed surgery for almost the same sound. A capacitor had become loose. Unfortunately it was right after Fender took SWR over ( 'nuther story)
  10. Had this identical problem. Your problem is most likely your Active Jack is not making good contact when not used and is not shorting the signal input to ground to keep it quiet when not in use. When you plug into the Active Jack, the input is no longer "Floating" and the Passive jack is grounded.
    You can fix this by opening it up, taking a small piece of 1/4" thick foam and putting under the contact arm of the jack to act as a spring to force it to close against the grounding arm.
    Worked like a champ for me. Your only other option is to replace the jack and it is not a standard "off the shelf" type.
  11. MODNY

    MODNY Guest

    Nov 9, 2004


    not trying to be a dick..but you aren't a supporting member, so i dont think you can say that.....
  12. nad

    nad 60 Cycle Humdinger

    Sep 22, 2005
    Thanks much, will try this at home!

    Well that's why I apologized, or didn't you read my entire post before criticizing? But just for you, I'll edit that post. :p
  13. nad

    nad 60 Cycle Humdinger

    Sep 22, 2005
    Foam didn't work, buzzing sound and distortion still present. :(

    Appreciate all the help, going to try another cab and head probably tomorrow, if it's the head off to a tech she goes. Or just sell it and get something else. This amp has NOT been abused and I'm going to be pretty pissed if I have to put $$$ into it when it's only 3 years old.
  14. i had a working man amp once...after about a year it would start shutting off on me for no reason...so i got an ampeg svt and never had a problem again...i also had an 8x8 from them and had nuthin but problems with that too...all pre-fender stuff...dump that stuff off at your local garbage dump and never look back!!!

  15. Humor me please, put a cord in the Active input but do not connect it to the guitar. You should still hear the buzz. Now tack something metallic and short it from the tip of the cable's plug to the sleeve. Did it go away?