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why is my limiter light going on?

Discussion in 'Amps and Cabs [BG]' started by thrashermatt, Mar 12, 2006.


  1. thrashermatt

    thrashermatt

    Jan 26, 2006
    western mass
    i'm getting the limit light from my ampeg svt350h when i play through my ampeg bse410hlf (400 watts at 4 ohms) and my legion 410(600 watts at 8 ohms)... i'm not putting out near the rated wattage on both cabs from my head but still getting the limiter light... why is that? is my head reaching its potential power and can't put out anymore? i always thought the limiter was for the speakers, but i can't understand why at least the legion410 would start to limit... any help would be appreciated
     
  2. Sundogue

    Sundogue

    Apr 26, 2001
    Wausau, WI
    You can read my reply in my other thread on my cab, but your amp puts out 350 watts into 4 ohms so it shouldn't be a problem.

    I don't know how you have your amp set up, but you may be boosting the bass too much. Low frequencies (particularly below 120 Hz) really rob power from your amp without really give you much in return.

    However, if you cut those frequencies below 120 Hz, and boost the frequencies between about 165 Hz to 220 Hz instead, you'll get a lot more out of your head without the limiter coming on.

    Those frequencies are the ones that will really give your cab some punch without being boomy (or robbing your amp of too much of it's power).
     
  3. Herman

    Herman

    Dec 25, 2005
    Lynchburg, VA
    Yes, your amp is reaching it's peak output and that's why the limiter circuit kicks in - to protect your speakers from excessive power due to clipping.

    From your amp's manual:

    "9. LIMIT: The SVT-350H uses an internal
    Optocoupler Limiter to assist in keeping the
    power amplifier’s output “clean” at extreme
    volume levels. (All amplifiers may begin to
    clip their output signals as they approach
    maximum output levels, resulting in potentially
    damaging distortion.) To engage the
    Limiter, depress the Limit switch. The adjacent
    LED will illuminate whenever the limiter
    circuit is activated. This indicates that
    the amplifier is nearing full output and the
    limiter is keeping peak signals from clipping
    the output."

    The limiter is a good thing and when it's LED is flashing that means it's working to keep the ouput to your speakers clean. I wouldn't worry about it coming on occasionally or during particularly loud portions of a song you're playing. I'd say that if it's coming on all the time (after you've tried Sundogue's recommendation), you don't have enough power for the volume levels you're trying to achieve and you may need an amp with more power (or more efficient speakers).
     
  4. thrashermatt

    thrashermatt

    Jan 26, 2006
    western mass
    ahh i see, thanks for the help... i'm looking at an ampeg v4 and/or an ampeg svt3pro now
     
  5. Herman

    Herman

    Dec 25, 2005
    Lynchburg, VA
    Are you driving both of your cabs with your svt? If so, this could be a large part of the reason your limiter is coming on. The svt is rated for 350 watts into 4 ohms while both of your cabs in parallel would be a 2.67 ohm load. If you want to run with both of these cabs, you should get an amp rated for a 2 ohm load.
     
  6. thrashermatt

    thrashermatt

    Jan 26, 2006
    western mass
    nope i'm not running them both together, i'm aware that the svt only goes to 4 ohms, so i stay away from going under.
     
  7. Sundogue

    Sundogue

    Apr 26, 2001
    Wausau, WI
    If you are looking at a new Ampeg head...and your looking for their "tube" amps, keep in mind that only the following are tube amps...

    SVT-CL/AV
    V-48H
    SVT-2PRO

    The rest are either SS with Tube Pre-amps, or all SS.

    Personally, I'm really GASsing for the SVT-2PRO. Way out of my budget right now, but that is one sweet amp (and that is coming from a die-hard Eden owner/fan).

    Though the SVT3-PRO sounded damned good as well through the BSE410HLF.
     
  8. thrashermatt

    thrashermatt

    Jan 26, 2006
    western mass
     
  9. Sundogue

    Sundogue

    Apr 26, 2001
    Wausau, WI
    I was just going off my Ampeg catalog, and what they offer now.

    I don't see a V-4 listed. Perhaps that is all tube.

    I played through every new amp Ampeg offers now, as my local shop is an Ampeg dealer and he has all their amps and cabs.

    I found a huge difference in the sound between the "all-tube" amps versus the SS with tube pre-map ones. The SS ones sounded a lot like my Eden...with the tube pre-amp giving it some warmth.

    But my God, All TUBE?!!! They are too awesome. The raw power and definition of every note is just too noticable to pass on. If only I had the cash for the SVT-2PRO.

    Way, way back in my early days I owned the original, classic, vintage Ampeg SVT head. That thing weighed more than me I think. :D