Am I reading this right? And why the difference?

Discussion in 'Amps and Cabs [BG]' started by kosmicwizard, Jan 27, 2009.

  1. From the Ampeg B4r owner's guide.

    13. LIMIT DEFEAT: The B4R employs internal limiter circuits to help keep the power amplifier's out clean at extreme volume levels. (All amplifiers may begin to clip their output signals as they approach maximum output levels, resulting in potentially speaker-damaging distortion.) These circuits may be disabled by depressing this switch. This may result in an increase in output power, but also increases the possibility of distortion. Use discretion whenever playing with the Limit circuits off.

    AND From the Ampeg B2re online owner's guide.

    9. LIMITER: The B2RE uses an internal
    Optocoupler Limiter to assist in keeping the
    power amplifier’s output “clean” at extreme
    volume levels. (All amplifiers begin to clip
    their output signals as they approach maximum
    output levels, resulting in distortion
    which may damage your speakers.) To
    engage the Limiter, depress the Limit
    switch. Whenever the amplifier is at full
    power, the adjacent Limit LED will flash.
    This is an indication that the limiter is keeping
    peak signals from clipping the output.
    NOTE: Playing at full power with the Limiter
    off will give you increased output power, but
    the sound may be distorted. Use discretion
    when playing without the Limiter.

    So as an owner of the B4r I should keep mine out and any owner of a B2re should keep theirs in, so they do not send out variable amounts of Wattage and potentially harm their speakers. Is this correct? And why would Ampeg do this? Cheers.
  2. bongomania

    bongomania Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    It's exactly the same thing, they just switched the switch. :) Why did they do that? Well, they've been asleep at the wheel for a long time.

    FWIW they are also spreading misinformation about clipping damaging speakers. That is 95% wrong. The only thing that regularly damages speakers is sending too much power into them. Now in fairness to the limiter concept, signal peaks (from aggro playing, a loud low B, etc.) can equal momentarily sending too much power into the speakers. So the device is valid and useful for some players, and they are right that defeating the limiter can get you more power at the risk of speaker safety. It just has very little to do with clipping per se.
  3. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    bongo, just to sidetrack a little, why is Chris Elliott posing with your dog? ;)
  4. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Depends on how you look at it. Clipping can damage tweeters, so if that was the intent of the warning it's 100% right. Of course, if your cab has no tweeters it's 100% wrong. Either way, it's not giving the consumer accurate information, and IMO that's 110% wrong. I doubt if you'll see any such warning in a the J-20 manual. :scowl:
    In any event, if Ampeg can't get it right it's not hard to understand why Jason is more likely to finally die, permanently, long before the myths surrounding clipping do.

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