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Amp Clipping - what to do?

Discussion in 'Amps and Cabs [BG]' started by ashtray, Aug 30, 2008.


  1. I have a Shuttle 3.0, and was playing it tonight having a good ol' time - running it through my 4 ohm SWR 8x8 cab (rated at 400+ watts), and the clip indicator light started coming on (in the power amp section, not the input gain clip light). :crying:

    I was playing a few different basses, but even with my passive bass, and with the input clip light barely coming (usually not lit up), the power section was clipping with my volume right around 12 o'clock. I had the bass knob DOWN one click from center, the parametric mid was set above the middle point (2 o'clock)- doing about a 3db boost on the upper mids, and had the treble up one click.

    I can't believe I ran out of head room. The volume was decent, but I could have used it louder. I'm pretty sure my GK 400RBIII head rated at only 240 watts has put out more volume through that cab (at that same club) in the past. :( Why is my 300 watt Shuttle calling it quits?

    Is it ok for the clip light to blink (not on steady)? Safe? Can I push the amp harder or will that just make the amp clip more and give me no more volume?

    Should I look in to buying a 500 watt power amp and run my Shuttle as a pre-amp to that for larger/louder gigs?

    I have an outdoor gig to play on Monday, and I'm concerned. At this point my GK head will get the call. I'll need all the volume I can get for that one - no PA support for the bass (just for vocals)... and the guitars get LOUD! :help:
     
  2. BUMP! Need advice - gig on Monday! Thanks!!!
     
  3. bongomania

    bongomania Gold Supporting Member Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    Use your ears- the clip lights are not a reliable indicator of the amp's performance. Listen for unwanted distortion, then turn it down until you don't hear that distortion. You may also find that you need to EQ this head very differently than the GK head in order to get the same perceived "loudness". Also PM one of the Genz guys on here, Hasbeen or Agedhorse, and ask their advice. They're super helpful.
     
  4. Toneman

    Toneman

    Jun 6, 2001
    Long Island
    Bring the GK to your show and get that head looked at. Also if your willing to spend money on a power amp you might consider a markbass little mark ll or F1 instead. They have all kinds of clean usable power and will give you all your looking for and more.
     
  5. I PM'd Hasbeen about a similar problem with my GBE 600 a while back, and as I recall, he said the clip lights come on significantly before any real clipping occurs. They are more there to indicate when you're beginning to reach the top of the volume range. I wouldn't crank it to the point where the light was always full on, but a little flickering shouldn't be a problem. Use your ears as the final judge though.
     
  6. LowBSix

    LowBSix Supporting Member Commercial User

    Mar 25, 2008
    818 ~ 805 ~ L.A.
    Endorsing Artist: GHS Strings
    You may be overdriving the low frequencies which cannot be heard, but will cause the power amp to clip...
     
  7. I didn't hear any clipping - but I was afraid of damaging my speakers by clipping the amp.

    I don't think the amp is defective - I was just surprised by the headroom giving up at only half volume, with the eq set pretty flat (not boosting any bass, slight upper mids boost only). I would have expected the amp to clip around 2-3 o'clock, not 12.

    If the clip light comes on "early", then I won't worry when I see if flashing... that will help keep me at ease. I had turned down the volume so the amp clip light didn't come on - but then my volume was a little low in the mix.
     
  8. Jefenator

    Jefenator Supporting Member

    Aug 22, 2008
    Oregon
    There's watts and then there's watts and then there's watts. Some manufacturers seem to like to rate their amps a little more liberally than others for some reason... :smug:

    I looked up that Shuttle amp and noticed it weighs less than 3 pounds. That's crazy light!! But I guess life can't be all gravy.
     
  9. HugoM

    HugoM

    Jul 3, 2008
    Miami, Florida
    The clip light is labeled as "CLP/LIM" suggesting that there is also limiting. So, blinking may be ok -- use your ears (I think I someone from Genz-Benz wrote that there's mild distortion before hard clipping begins).

    Others know more but since you have a gig Monday, I thought I should write something.
     
  10. If you're doing and outdoor gig then surely you will have PA suport? DI into that. In a big gig situation your amp is only a monitor.

    The difference between 240W and 500W is only 3db, which is the difference between your audience standing 15m away or 21 meters away. With (say) a 3Kw rig, that extra 250W is easily accounted for.

    Use the force luke.
     
  11. hasbeen

    hasbeen Commercial User

    Sep 23, 2004
    Vice President, KMC Music. Warwick U.S. distribution, Ampeg distribution
    And we don't...since you brought it up. We even go to the trouble of explaining how we rate our watts and why on our site. :bassist:
     
  12. hasbeen

    hasbeen Commercial User

    Sep 23, 2004
    Vice President, KMC Music. Warwick U.S. distribution, Ampeg distribution
    to the OP- as mentioned here, use your ears. Our lite comes on very early and, there's also a unique limiter circuit that we use. So, if it sounds good, it is good.

    On a side note: you mentioned that because your knob was at 12:00, you were at half volume. With any amp brand, the knob position doesn't really indicate where you are in your volume setting. ...half vs. 3/4 etc. People use different gain structures and pot tapers.
     
  13. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    The CLIP-LIMIT LED shows that the amp is entering the limiting range, and there's still 6dB of limiter compliance before the power amp clips. Please look at your owner's manual for an explaination of how the output limiter works. (It's not defeatable, hence the dual function of the LED).
     
  14. will33

    will33

    May 22, 2006
    austin,tx
    Sounds like the same advise as with most any other amp, a little flashing on a hard note is ok, if it's on steady you need to back off and always follow your ears. The rig will tell you when it's trying too hard. Good point about the pot taper, I've had amps that are into hard clipping not much past noon and others that had to be close to cranked to get up to volume and didn't clip/distort.
     
  15. Thanks for all your answers - especially the GB guys. I didn't think anything was wrong/defective, and I didn't think the 300 watt rating was untrue - I was just concerned about the amp clipping. 6db more to go? That should be more than fine!

    Unfortunately, my band uses NO PA support for instruments. Drives me crazy - but then again, we don't get paid much, so there's no funds to rent proper PA equipment, and no one in the band is going to pay for a full on PA. (We use a Mackie 800 watt powered mixer, and a pair of Mackie speakers.)

    That makes outdoor gigs tougher on me. Playing in a field for about 300 people with no buildings around.

    I think I will stick with my Shuttle for the gig, and keep an eye on the clip light - allowing it to flash, as long as it's not steady. The Shuttle amp sure sounds better than my GK, that's for sure - and easier to dial in my tone for the room with the parametric mids.
     
  16. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    A small reality check... you are trying to cover an outdoor field with bass, and with no PA support, a relatively inefficient cabinet and a 300 watt amp. I think you might be asking a bit more than is "reasonable" for any 300 watt amplifier. It will help to not use the LF Extend, and most importantly that the rest of the band play within reason and in context to what your bass rig is capable of.
     
  17. LF Extend? Ok - lost me there.

    Yeah, I know it's asking a lot for this setup to play a large field. My only other option is to bring a second rig and run them side by side. And that *is* tempting. Only thing more tempting is run a 3rd rig next to that! :D But my wagon won't hold that much stuff. The 8x8 and my basses take up a lot of the space.
     
  18. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    I know this seems like a totally crazy idea but have you considered reading the manual?

    Alex
     
  19. hasbeen

    hasbeen Commercial User

    Sep 23, 2004
    Vice President, KMC Music. Warwick U.S. distribution, Ampeg distribution

    LF Extend = Low Frequency extend. It is the first button on the left within the Signal Shaping Circuit.

    I'm glad we were able to help but I do think it would be helpful to read the manual. It will cover the gain stages,clip lights, signal shaping circuit etc. It will help you get the most out of your amp.

    Our manuals are all on-line at www.genzbenz.com

    I hope this helps.
     
  20. Sorry - completely zoned for a second there... I don't use the eq buttons, so I completely forgot about them! No, I wouldn't have set the LF Boost "in" - that's for sure.

    As for the manual... yeah, oops. It's around... somewhere. Time to go online and download another one!
     

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