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Any downside to Digital power sections?

Discussion in 'Amps and Cabs [BG]' started by bubbastain, Dec 18, 2012.

  1. bubbastain


    Oct 1, 2012
    I read a bunch of threads about different amps with the digital(sorry, Class D) power section and couldn't really find anything that mentions any possible issues or concerns. A few months ago when I was in the market for an amp head, the sales person advised against some of the small lightweight Class D heads. He mentioned something about playing loud for extended periods would overheat it or something like that. Any truth to this? Any downside or possible concerns? Is a Class D watt equal to a SS watt? I really like the Kustom Deep End 300 head I have but when I saw the Kustom KXB500 head(the price and reviews by some of you guys), it made me consider the little 5 pounder.
  2. guy n. cognito

    guy n. cognito Secret Agent Member Gold Supporting Member

    Dec 28, 2005
    Nashville, TN
    No issues. Lemme guess.....he wanted you to buy a tube head???
  3. Jazz Ad

    Jazz Ad Mi la ré sol Supporting Member

    First thing first, class D is NOT a digital power section. It's all analogic.
    They indeed cut off abruptly when they overheat. Typical class A/B amps don't do that. They withstand the additional charge and eventually break.
    To avoid going off limits, class D amps tend to come with humongous output powers. It is hard to reach the limits on a 500+ w amp.
  4. BassIsFun17

    BassIsFun17 Supporting Member

    Jan 16, 2006
    yeahh i think class D power sections are great. I have a GK MB210 combo. and the amp gets plenty loud, but I've blown my speakers and just got them replaced. I hope I don't do it again.
  5. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    They will never replace my tube gear, but the small amps will darn sure do the job for me and sound excellent when lugging tube gear is impractical.
  6. bubbastain


    Oct 1, 2012
    :) Actually, they didn't even have any tube amps. I was in there specifically to check out the Hartke LH500. Ended up liking the DE300 more. Didn't even plug into the small units.
  7. fdeck

    fdeck Supporting Member Commercial User

    Mar 20, 2004
    Madison WI
    HPF Technology LLC
    I've gotten over the hangup about calling these amps "digital." I've got a Class-D head for those occasions when lugging my other Class-D head is impractical. ;)
  8. I prefer Digital. Loud. Light. Reliable. Super clean and transparent. They take your input and make it louder without any color added.
  9. as far as overheating. I've ran mine HARD for 4 hours straight, outside, in the summer and it's barely warm to the touch. The carpeted top of my cab is hotter than the amp in the back.
  10. bubbastain


    Oct 1, 2012
    Just what I want to hear. Thanks
  11. wcriley


    Apr 5, 2010
    Western PA
    Because class D is more efficient, it doesn't generate as much heat as class A/B.

    As a result, maybe some of the designers of early class D bass amps scrimped too much on the cooling/ventilating?
    It sure hasn't been a problem with any class D amps I own.
  12. I like em better than yr trad ss amps. Never had a problem with any class D amp. They sound great, are lightweight. Tubes are always my fave, but class D are a fantastic alternative
  13. the gallien kreuger mb115 i owned was great. plenty loud, light, dependable. had to sell, but i wouldn't be opposed to buying class d again.
  14. Handyman


    Sep 4, 2007
    Austin, TX
    The only practical downside to class D amps is that they're significantly more complex than plain old class AB, and you won't be able to drop them off to any old repair shop should the need arise.

    That said, I use a Genz Benz Streamliner, and don't see a reason to go back to the old stuff.
  15. ThisBass


    Aug 29, 2012
    But it's PWM.
    Pulse Width Modulation.

    It's "analogic" but still PWM contains a lot of "0" and "1" at the power stage, and that's a similar meaning like digital.
  16. Red Planet

    Red Planet

    May 29, 2005
    Talking Rock GA
    OEM Manufacturing Supplier
    So what is the difference between a ultra lightweight Class AB amp and a ultra lightweight Digital amp and the same in a Class D amp?
  17. Class AB is less efficient and produces more waste heat.
  18. Mehve


    Jun 2, 2012
    Kitchener, ON
    Class D's had a few teething issues way back, but they're nicely matured by this point.

    They've also gotten to the point where different class D's have well-established characters. If you have an idea on what sort of sound you're after, picking the right amp can give you a good headstart on getting there, just like any other family of amplifiers. Lots of threads and posts on all the big names, definitely worth working the search engines on them.
  19. BassIsFun17

    BassIsFun17 Supporting Member

    Jan 16, 2006
    for the people who've tried class d amps, how much of a difference does the tube preamp section make? for instance, mb500 vs mb fusion 500?
  20. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    That all depends on the execution of the tube. In stuff like the SVT 7 Pro and Streamliner amps, a lot. In the case of others where the tube is wired in a starved plate design, it has a little impact but it's less important to the sound. In other words, tube preamps behave pretty much the same in micro power amps (not all micros are class D, BTW) as they do in trad. SS amps.