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noisy/farting rig

Discussion in 'Amps and Cabs [BG]' started by Matthew Whittle, Nov 12, 2018.


  1. Hi guys,

    Just scored my dream rig: Orange AD200 MKII with an Ampeg SVT 410 Classic.
    Unfortunately, bought both second hand, and I've got an issue with them farting a little bit.
    I took the grill off the cab and thought it was the bottom-right speaker, so I replaced it like-for-like with what was in there, Eminence 10". Still getting the farts.
    Any clues on what the prob might/will be? I've searched the forums, seems the consensus is that it'll be something overloading, i.e. the amp is too powerful for the cab. But it all seems like it should work without issue?
    I don't wanna take it to some tech wiz only to find out it was something dumb I was/wasn't doing.
    Cheers
    Matt
     
  2. Roland GR 88

    Roland GR 88

    Sep 16, 2013
    Whitby
    If you can, try the head with another cab and your cab with another head. Use a different speaker and patch cable, check your batteries if there are any in the chain. Once you isolate the problem you can move forward.
    BTW....those tech wizzes can be pretty useful and discovering you've done something dumb is usually worth the price of admission. Plus, it will save you the time and money replacing parts that don't need replacing.
    Good luck :)
     
    Last edited: Nov 12, 2018
  3. Does changing your EQ make a difference?
    Try cutting the bass and mid bass significantly.
     
    eriky4003 likes this.
  4. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    Taking it to a good tech might be cheaper than replacing the speaker you already replaced...
     
  5. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    Any new rig should be checked out by a tech. Consider it part of the purchase price when debating whether to buy new or used. Unfortunately, used sometimes comes with issues.

    As was mentioned, separate the amp and cab and test each with other equipment. That will allow you to determine where the issues are.
     
    Garret Graves likes this.
  6. Wasnex

    Wasnex

    Dec 25, 2011

    How loud are you playing? The AD200B typically makes about 165W before it starts breaking up. The amp seems intentionally designed to produce distortion, although it does sound really nice when run clean. If you have a bass with hot pickups, the preamp may start to drive with the Gain as low at 9 o'clock. If you run the bass control very high it will eat up the power really fast. I usually run the tone controls as follows: Bass 9-10, Mid 2-3, Treble 7-8. For max clean power run the Master wide open. If you want preamp drive, reduce the Master and dial up the Gain to taste.

    Since you bought both used, either could be damaged. A properly functioning Ampeg 410 should handle the AD200B with no problems. Since the AD200B has tubes, it's possible the bias for the output tubes is set improperly or some of the output tubes have stopped working. If the tubes stop working in pairs, the amp may continue to sound normal at low volume but not produce much power.

    Make sure you have a good speaker cable and it is plugged into the correct impedance output. The amp is setup to run with either an 8 ohm or 4 ohm load, but the labeling on the back is a bit misleading. Connect one 8 ohm speaker to the 8 ohm jack. Connect one 4 ohm speaker to a 4 ohm jack. Connect two 8 ohm speakers, one to each 4 ohm jacks. You cannot connect two 4 ohm speakers to the 4 ohms jacks as this will produce a 2 ohm load, which is an impedance mismatch.

    I don't know how well this amp copes with impedance mismatches. At the very least, running an impedance mismatch will reduce the output power and increase tube wear. At the worst, running an impedance mismatch could cause severe damage to the amp.

    IMHO, a trip to a good tech seems sensible.

    See page 8 of the attached manual for impedance and speaker connection info.
     

    Attached Files:

    eriky4003 and Jim Carr like this.
  7. Jim Carr

    Jim Carr Dr. Jim Gold Supporting Member

    Jan 21, 2006
    Denton, TX or Kailua, HI
    fEARful Kool-Aid dispensing liberal academic card-carrying union member Musicians Local 72-147
    That head is pretty much designed to have a lot of dirt when even only slightly pushed. Could that be it?
     
  8. BogeyBass

    BogeyBass

    Sep 14, 2010
    More Fruit, less Nachos.

    Test the Amp with another cab.

    Test the Cab with another amp.

    Could be poopy speakers
    Could be poopy amp.

    Hopefully the cab was not abused.
    Sometimes you get lucky and speakers are loose or wire is rattling against the cone.

    Sometimes not lucky and seller sold poopy cab

    Sometimes amp sounds really bad and just needs new pre tubes/ phase inverter

    Make sure your on the correct impedance tap.
     
  9. 1st order of business is make sure all the drivers are pushing and pulling together by doing the battery test.

    9v battery briefly applied across exposed end of 1/4" cable should make a awful thump with all speakers going same way. Normal is positive to tip makes them jump outwards.
     
  10. flatwound62p

    flatwound62p

    Apr 24, 2017
    Australia
    This one. It's happened to me more than once with used cabs where somebody has made a mess of the polarity. If you can pull the front or back off the cab you can watch closely when you do a battery test and make sure ALL of the cones move forward as you touch the battery terminals to the cable.
     
  11. Hey guys,
    Firstly, thanks so much for all the replies. Super helpful. I unfortunately haven't found a tech over the christmas period who's able to help me out.

    That all said, I have been playing through a hire Ampeg 8x10 at band jams, and it's been sweet.
    Last night, went to a different practice space and hired an Ampeg 4x10, and got the same problem as my own Ampeg: farty, yuk rumble resonance from the cab, with the amp dialled in at about 9-10 o'clock master and gain.

    Could it be that the AD200b is simply too powerful for an Ampeg 4x10?
    I feel like I've seen the amp used on that cab before at gigs, but it's weird that coincidentally it's been a problem on two separate Ampeg 4x10s ...
     
  12. Wasnex

    Wasnex

    Dec 25, 2011

    If you are getting the same exact problem with a different Ampeg 410s I suspect your tubes are on their last legs or the tubes need to be rebiased. The 810 is a more efficient so it will give you a bit more headroom. So maybe you are just having to push the amp too hard with the 410.

    Is the cab in question a 410HE or 410HLF. It matters because one is an 8 ohm cab and the other is a 4 ohm cab. If you create an impedance mismatch between the speaker and amp, it will reduce the amount of power the amp can produce.

    How does the 810 sound if you push the AD200B into distortion? The 810 does not have a tweeter, while both of the Ampeg 410s do. Tweeters generally don't work well with distortion. Simply dial the tweeter back with the attenuator on the back of the cabinet.

    For max clean power, set the AD200B master fully CW and use the Gain control to set your volume.
     
  13. WannaJazz

    WannaJazz Supporting Member

    May 7, 2010
    On Eden cabs, if you use the speakon jack, and leave the 1/4" plugs open, it will make a noisy/farting rig.

    They used to send a pair of these plugs with each new cab.

    1-4-inch-Black-Hole-Plugs.
     
  14. HOOLIGAN

    HOOLIGAN

    Dec 21, 2007
    Cowtown, USA
    If the cab is a certain era (8ohm) 410he, those can lose steam rather quickly.
    I have one that does the same farting out with my Orange Terror Bass 500.
    No issues if I run another 410 with it, or use the head into an 810e.
     
  15. Hey guys,
    • Cab is a 2007 SVT410HLF - here's the full specs from back
      IMG_0590.JPG

    • I ran the 9V battery test, all four cones move outward
    • I'm running from one of the 4ohm outputs from the AD200b, so shouldn't be an impedance mismatch
    • Definitely not the tubes from the amp - I push the amp HARD on the 8x10
    • I've checked for loose wiring and screws, nothing like that
    • Took photo of inside circuitry, so someone smarter than me may assess and make sure it looks kosher:
      IMG_0585 (3).JPG
    • Made a video of the rig doing its thing ... it's at about 45 seconds in that you can really hear what the issue is ... it's like a fuzzy distorted tone (as opposed to the distortion intended from the amp gain - I can tell the difference) coupled with a weird fuzzy resonance after each tone. This was with both the master and gain at about 10 o'clock.
    Still at a loss as to what the problem is. The sound issue seems to be across all speakers, so I doubt it's just one dodgy one, but I could be wrong (I'm pretty uninformed when it comes to this stuff).

    Desperately trying to avoid/minimise my spend on repairing this, by trying to get it diagnosed in advance.
    Thanks all!
     

    Attached Files:

  16. Wasnex

    Wasnex

    Dec 25, 2011
    I have to admit that sounds pretty awful...like a blown driver, or something rattling against one of the cones. So driving the 810 with the exact same settings produces nice tone? Also, you have gotten the same crappy sound using two different 410HLF cabs?

    If the answer to both questions is yes, here are some possibilities. Either you found two bad 410HLF cabs, or the AD200B doesn't play nice with the varying impedance of the 410HLF, or the speaker cable is vibrating in the plug and making intermittent contact, or a component in the amp is vibrating from sitting on the head and making intermittent contact.

    Try another cab, try holding the speaker cable in place so it can't vibrate, place the amp on the floor so it is isolated from the amp....a final suggestion, turn the tweeter off.

    The AD200B only puts out about 165 watts clean. Most of the players who love the 410HLF use huge solid state power amps that put out major power...I would be extremely surprised if the AD200B has enough juice to push the cab beyond it's limits, but I guess it's possible.

    What tone control settings are you using?
     
    Matthew Whittle likes this.
  17. Wasnex

    Wasnex

    Dec 25, 2011
    @Matthew Whittle I put my AD200B into playing rotation so I could try out your gain settings. My bass, mids, and, treble are at 10, 3, 9 o'clock. I put the gain and master at 10 and plugged into the passive input with my Yamaha TRB6P with the tone controls set flat. The TRB6P is an active bass but the output is only a little hotter than a passive bass. The amp was really only making probably 5-10 watts at most. This is enough to rattle junk in my basement, but not enough to cause any sort of excursion problems with a healthy 410HLF. The rattling cabinet doors sound kinda similar to the sound your getting :vomit:. Course the signal level of your bass will have a lot to do with how much power your amp makes as well.

    If possible, try another cab with the AD200B or try another amp with the 410HLF.
     
  18. DiscoRiceJ

    DiscoRiceJ

    Oct 15, 2018
    Replace the batteries in your bass first before going any further. Some of that sounds like battery death.
     
    guitarflinger likes this.
  19. Rockbobmel

    Rockbobmel Supporting Member

    Sounds like a handle rattling to me.
     
    patrickj likes this.
  20. @Wasnex, thanks heaps for your detailed responses! Yes, two different svt410s, although I think the one at the practice space was a HE.
    Checklist for today:
    • try the cab with the amp sitting next to, not on top of
    • try different amp & cab inputs/outputs (both the amp and the cab have multiples to use)
    • dial out the tweeter to see if that makes a difference
    If none of that works, next week my techy mate is gonna come around, we're gonna test each speaker individually, to see if we can single out the prob.

    @DiscoRiceJ I'm on a P standard, so no battery in the guit.

    @Rockbobmel you mean on the cab or the amp? handles on both seem to be very tightly attached.

    Thanks again everyone!
     
    DiscoRiceJ and Wasnex like this.

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