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Righty i have a problem! Big time!

Discussion in 'Amps and Cabs [BG]' started by merlin, Apr 27, 2001.


  1. Help!, ok, i have noticed that lately my amp/cab combo sounds like i have a fuzzz pedal through it.

    I had my amp checked on another set of 4X10 and it sounds great, no fuzz what so ever. So then i thought maybe it was the 9 volt battery, so i changed it. Still fuzzy. Then I used a really expensive lead... still fuzzy, even got my brother to play guitar through it on a clean setting and it was fuzzy through my 4X10 cab and not on the other one.

    My question is, what could possible be wrong???

    Merls
     
  2. Could your speaker be ripped? I don't know cause I'm not a technician like some of the guys here (MikeyD?).
     
  3. Well that was quick! i proof read my thread and i had a reply already. I know they're not ripped because the cab has a wide gauge grill, so i can see the speakers. Which really annoys me because its a custom built cab so i can't tell you what brand it is.

    Merls
     
  4. Could be a blown speaker or loose connections.
     
  5. Sounds like a blown speaker to me. Or maybe one of your cones is seperated from the surround. (you wouldn't necessarily see this). Oh, I just thought of something else. Maybe a magnet or a basket has shifted. This will cause the voice coil to rub on the magnet, producing odd sounds. Take the grill off and push each speaker in with as even a pressure as you can. If it makes a scraping noise then you've got a problem. While you're at it carefully check the cone/surround junctions for rips. The surround is the part that joins the cone to the frame at the outside edge. If you still can't find the problem, maybe you could unhook all but one speaker at a time to find the offending driver. Hope this helps.
     
  6. I had this problem once with an old amp (slightly modded by me.. hence the prob) anyway it distorted like man and guess what? It was the speaker lead that was shorting.. just a little so to speak.. I got the sound but it was distorted. Check your speaker lead if you havent already done that. My $0.05 . :)
     
  7. MikeyD

    MikeyD

    Sep 9, 2000
    My advice: read Spacegoat's advice! :)

    (Thanks, Space! Right on!)

    - Mike
     
  8. Right i'll give it a go, thanx for the quick reply. Could the quality of speakers also affect the longevity of them? I was told they were top of the range.

    Second i changed the scratchy volume pot on my bass, and now i have a certain parent screaming at me because "You shouldn't have touched that! now i know why your amp sounds fuzzy!" Changing that shouldn't affect it because i have a practice amp and i don't get fuzz...

    Merls
     
  9. But would one blown speaker make them all sound distorted??? Its even in all the speakers. I've blown speakers before, i don't think it could be that.

    Could it be the wiring to the speakers in the box??

    Merls
     
  10. some wire might cause a short somewhere, making the amp go fuzz.

    One speaker blown doesnt make it all fuzz... unless you dont have more than one speaker that is ;)

    Go check the wiring with a ohm-meter or something that will tell you where the problem is.. probably.
     
  11. Niels Keijzer

    Niels Keijzer Guest

    Nov 27, 2000
    Did you know that the bassist from Faith No More played Peavey because the speakers would blow easily, and he was after that sound?
     
  12. AssMan

    AssMan

    Dec 2, 2000
    Minnesota, USA
    Bad speakor cable? Did you use the same cable while testing the different cabs? I'd check the wires in the cab too. What type of cab is it (1x15", 4x10", ect..)? Did you do the speaker push-test? If you did, what was the outcome? If you didn't, be very carefull when you do. Does your cab have a crossover network? If it does than it might be not hooked up right or blown.
     
  13. ..lets just say "I'm not allowed to touch anything" anymore. I'll spare the details. I have a 4X10 cab, yes i used the same cable when testing it.

    What also need cleared up is, by changing the volume pot on the bass, could that have any affect whatsoever?? I just need to know cause its a hot arguement at my place cause "you shouldn't have touched anything", and if its not my speaker cab and its the bass, them i'm dead basically... :eek:

    Merls
     
  14. AssMan

    AssMan

    Dec 2, 2000
    Minnesota, USA
    You said you tryed other amps with your bass and they didn't fuzz, so it's not your bass. If it is the pot, it's real easy to fix. I disagree with the "don't touch anything" policy, if you don't, how do you expect to learn anything, or be able to fix things your self. I find fixing my own **** much better than getting it fixed (I'll usally do a better job than a repair shop would anyway, doing it your self is much cheaper and conveint too), because then if it doesn't work, it's my own damn fault and the worst that can usally happen is I'll ending up having to fix it again. Don't try this kind of stuff if you think you can't handle it or if your in over your head though or you'll be sorry, but fixing a pot is no big deal. Did you try using a different speaker cable? If no, do it, if yes do it again. Have you check any of the internal wiring in your cab? If it's not the cable, the amp, the bass, or the speakers, it must be the crossover. Just unscrew the plate in the back of your cab and gently pull out the cross over (be carefull not to pull it too far or you could pull out some wires) then inspect it for any loose wires or solders, then get a flash light and look in the cab to make sure the speakers are all hooked up. Make sure your guitar cable is hooked up to your bass and amp right too, jiggle them around and see if that does anything. What head are you running?
     
  15. AssMan

    AssMan

    Dec 2, 2000
    Minnesota, USA
    It can. Did you put in the right type of pot (the right impedence like 250K, 500K, 25K)? Did you wire it up right? Are your soders secure? Did you double check all your wireing? You said before the pot was scratchy, why did you replace it instead of just cleaning it? Most times, scractcy pot = dirty pot, unless it's worn out, but it usally takes alot of time and abuse to wear a pot out.
     
  16. Ok, i measured the pot and it was around 90k, so i put in a 100k, was the only thing i had. I am studying electronics and feel right at home doing it. afterall i am building my own 100 wattpower amp with rack preamp! See the bass is my dads yet he solely lets me use it. Refers to it as mine etc, but as soon as something goes wrong and i take the liberty to have it fixed... "Well see how long you can duck the axe" basically.

    That is why i wouldn't be able to look at my cab, i don't want to push it. heehee. This plate you were talking about? I don't have one, its a fully enclosed carpeted box. It was custom built so its probably well hidden.

    The amp is an old PA head with a front end used for guitar. Its a transistor amp (ohhh yeah!lol) of 100 watts into a 600watt cab.

    Merls
     
  17. old_skool

    old_skool

    Aug 17, 2000
    Milwaukee, WI
    how do you clean your pots? why do pots become scratchy? i ask because my volume pot makes some nasty sound somtimes and im wondering why and if i can fix it. thanks.
     
  18. I am unsure how they become scratchy. Probably has a lot to do with dust etc. I used to clean them some spray oil right in the winding joint, help lubricate over that spot.
    But with active electronics, by the time i got to mine i figured "Stuff it i'll change it".

    I have noticed on my bass that the 9v battery doesn't make very good contact with its clip, i tried taping it down. Just occured to me that maybe that could affect my sound too.

    Merls
     
  19. AssMan

    AssMan

    Dec 2, 2000
    Minnesota, USA
    How to clean a pot? Caned air and wd40 straw. If that doesn't do it, then oil it up a bit. Contact cleaner is best though. There should be a hole in the back or side of the pot somewhere.
     
  20. AssMan

    AssMan

    Dec 2, 2000
    Minnesota, USA
    What model and make of bass is it? Actives usually use 25K's, mine uses 50K's, but I've never seen an active bass with 100K's. Wasn't the impedance printed on the pot? From what I've experienced (at least with cab impedance) is that the printed impedance is nominal, and your read out is usually off quite a bit from what the nominal impedance is, I don't think this applies to what we're talking about, but it does apply to speaker impedance measuring.

    I'm talking about the thing the input jacks are mounted on. Usually the 1/4" inputs are mounted on a plastic or metal indented plate on the back of the cab and the crossover is usually on the other side of it. Did you build the cab, or was it like one those lynx kits off of Ebay?

    That's probably the problem right there. When I've made amps by linking together old stuff together they were trouble, it worked, but if I cranked it, the connections would shake loose and make bad contact (I had to use $40 worth of adaptors for it work though). I can see why you're building your own. Bass amp pre-amp guts are pretty complex especallily if it's a S.S. tubes aren't to bad though, I'd just go buy a used bass pre-amp and use it or pirate it's guts rather than try to build my own, but if you want to build it your self, more power to you.