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Ampeg SVT350H Clipping -- Bad?

Discussion in 'Amps and Cabs [BG]' started by babecker, Jan 17, 2003.


  1. babecker

    babecker

    Mar 7, 2002
    Sykesville, MD
    My amp's clipping light comes on whenever I dig in while playing and I'm not really sure why:

    I run my SVT350H (350 watts @ 8 Ohms / 200 watts @ 4 Ohms) through an 8 ohm Ampeg 115SE (rated 200 RMS) and an 8 Ohm SWR Workingman 410T (rated 400 RMS) hooked up in parallel. I run the gain at noon and the master volume at noon, with the -20dB switch engaged (I'm using an active Ibanez ATK). I don't really see why the amp is clipping like it is. I saw some other threads where people mentioned that not running enough power into cabinets can cause clipping. Could this be the source of the problem?

    Since I'm a moron, I've been running this clipping signal for a good year and a half, without ever stopping to think it might be bad...:rolleyes:

    What kind of damage am I possibly subjecting my rig to, and what can I do about it? Thanks for any help!
     
  2. Ívar Þórólfsson

    Ívar Þórólfsson Mmmmmm... Supporting Member

    Apr 9, 2001
    Kopavogur, Iceland
    Here is a little advice to help you prevent clipping:

    1. Turn the Gain and Volume down.
    2. Play your bass and dig in has hard as you normally do. Raise your gain until the clipping light goes on (I presume there is one). Then back the gain off a little.
    3. Set the volume to your liking.
     
  3. babecker

    babecker

    Mar 7, 2002
    Sykesville, MD
    Thanks, that seems like good advice; however, it seems to me like I'm not really pushing the amp that hard, despite the fact that the clipping light keeps kicking on... or does this clipping at my current settings seem normal to everyone?
     
  4. monkfill

    monkfill

    Jan 1, 2003
    Kansas City
    That seems a little early for the clip light to be coming on, UNLESS you have something on your EQ (either on the amp or on your bass) really cranked. For instance, if you have the bass knob cranked on an active bass, this will probably do it. Try setting your EQ flat and the tone on your bass flat and see if it continues to clip this early.

    If your amp is clipping, it could be damaging your speakers.
     
  5. babecker

    babecker

    Mar 7, 2002
    Sykesville, MD
    Ah, i see. I do run the bass fairly high on the bass preamp and the amp. I guess that's what's doing it...I really need more power anyway. ANyone have a tube SVT they want to sell me?:D
     
  6. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    Clipping usually happens at the input point of the amp. The best way to get rid of if is to turn the pre-gain down and turn the post-gain (volume) up to compensate. I know lots of people who run the Post gain (volume) at full tilt and use the Pre-gain to controll levels, and it works a treat. I know it sounds back to front but you've got no hope of clipping at the input stage and you don't lose any volume.

    EQ can also blow speakers but in a different way to clipping. CLipping will burn the voice coil but too much bass EQ will physically tear the speaker appart by making them over-woof. If you were over-woofing, you would have heard it for sure and stopped it ages ago coz it makes your bass sound like crap. Clipping distortion isn't always audible which is why all amps should have a warning light.
     
  7. monkfill

    monkfill

    Jan 1, 2003
    Kansas City
    That will do it.

    I have a tube SVT. I will not sell it. :D
     
  8. babecker

    babecker

    Mar 7, 2002
    Sykesville, MD
    What bass & cab are you using with your SVT?
     
  9. monkfill

    monkfill

    Jan 1, 2003
    Kansas City
    Modulus Flea 5 > Ampeg SVT-CL > SVT-810E

    Not a *real* SVT but I'm still in awe.

    I don't think a cabinet itself will cause your amp to clip sooner. . . although, a less efficient cabinet will make your amp work harder to produce the same volume that it could produce with less power in a more efficient cabinet.

    On the other hand, once everything was set up at home, I tried the 300 (tube) watt SVT-CL through the 8x10, then I tried my 350 (SS) watt SWR 350x through the same 8x10. I began laughing hysterically. The SVT-CL produces at least twice the apparent volume.
     
  10. monkfill

    monkfill

    Jan 1, 2003
    Kansas City
    What I mean is that your clip lights should light up with all your settings in a given position, no matter what cabinet is connected to it.

    On my 350x, I could crank the bass on the head and on the bass itself, and make the gain clip light come on at about halfway on the gain dial. I could then set the all the tone controls to flat and almost get away with having the gain set at full without clipping. EQ makes a huge difference, especially with an active bass.
     
  11. tim4003

    tim4003

    Apr 30, 2002
    Dawsonville , GA
    Sorry babecker,
    I'm afraid you got that backwards.
    It should read "350 watts @ 4 ohms / 200 watts @ 8 ohms."
     
  12. If you're just seeing the clip lights flashing a bit when you dig in and there isn't audible distortion, I wouldn't worry about it. A lot amps' clip lights come on before any clipping occurs. Also, "not send enough power to the cabinets" won't cause the amp to clip. The amp will clip at the same level whether it's connected to a 100W or a 1000W cab. Amps only clip when they're turned up to where they can't supply clean power. The operator always has control of that.;)
     
  13. cb56

    cb56

    Jul 2, 2000
    Central Illinois
    Ok let me chime in here.
    As stated before, Turn the bass eq on your bass guitar down . It doesn't need to be cranked on an active bass. A liitle over half way should do. You have plenty of eq on your amp to get the low end you need. By the way you don't have to use the
    -15db pad unless you really feel it necessary. I use a Warwick active bass with loud pick ups and still use the 0db input. Turn the pre amp gain up until you are seeing the RED light flicker when you play really hard. If that's at the 12 o'clock position so be it. That's about where mine stays. Make sure the limiter is on. Most if not all Ampegs have them. I know the SVT 350H does. Turn the main volume up until you are happy with the volume. If the YELLOW limiter light flickers when you play that is ok. That means the limiter is doing it's job protecting your speakers. If it stays on all the time you either need a more powerful amp or more speakers. Hope this helps.
     
  14. Good post, cb56!
    This method of setting your amp's gain structure will give you the best signal/noise ratio and the best tone out of your preamp. Again, the odd flick of a clip light isn't a big deal.
     
  15. monkfill

    monkfill

    Jan 1, 2003
    Kansas City
    Whether the EQ is cranked on the bass or on the amp won't make any difference. . . its the level of bass that will cause the preamp to clip. Adjusting the EQ on your amp upwards will cause your preamp to clip at a lower level on the gain, just as it would if you turn on the bass on your bass. The only difference is that the your bass might cut and boost at a different frequency than the EQ on your amp, giving you some options.

    There are several things to consider. First, cutting frequencies instead of just boosting. Just experiment, and you might find that you don't need to boost the bass as much if you cut certain midrange frequencies. Second, you probably don't need to crank the bass as much at higher volumes as you do at lower volumes. When you turn up the volume, try easing off on the bass EQ, then you can turn up your overall volume a little more before clipping. After you've exhausted experimenting with the EQ, and you need more power, get a tube SVT :D
     
  16. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago
    SVT 350Hs and its rack mount twin the B2R are somewhat underpowered, or liberally rated however you want to look at it.

    Are you running the amp with the limiter on? If so, turn it off and listen to it.

    If you need greater volume, you probably need a different amp. If you crave the Ampeg sound, you could get a SVP preamp and any poweramp you want...

    Good luck!
     
  17. Audiosolace

    Audiosolace Guest

    Oct 8, 2002
    Knoxville, TN
    Ahhh, now that's refreshing. :D
     
  18. cb56

    cb56

    Jul 2, 2000
    Central Illinois
    so, am I wrong ?
     
  19. babecker

    babecker

    Mar 7, 2002
    Sykesville, MD
    Thanks for the insights, fellas.:)