Class D vs solid state?

Discussion in 'Amps and Cabs [BG]' started by TTA, Jul 21, 2021.

  1. TTA


    Jun 10, 2021
    This may seem super dumb… but after being out of the scene for 10+ years… i see a lot of reference to “class d amps.”

    is that just code for solid state? Or have designs changed?

    i came from a solid state/hybrid/tube amp era.
  2. Zbysek


    Mar 23, 2017
    Czech Republic

    TheReceder likes this.
  3. TTA


    Jun 10, 2021
  4. Zbysek


    Mar 23, 2017
    Czech Republic
    You're welcome. I am not able to provide more detailled explanation.

    But others will chime in...
  5. Passinwind

    Passinwind I know nothing.

    Class D amps are nearly universally a subset of solid state design, as Classes A, AB, G, H, T, etc. can also be. The big difference is enhanced efficiency and hence reduced size and weight, as a quick look at the market place will show.
  6. TTA


    Jun 10, 2021
    Yeah wikipedia had a good article that quickly went over my head, but basically more efficient design… less heat, smaller heat synchs, so more power per weight/size of amp.

    and for whatever technical reason they sound terrible (more than old solid state) with clipping… so they get lots of headroom bit i guess they take better to digital effects/distortion.

    all part of technology making things more efficient, compact and light. Mind you, the basic realities of physics do limit how light a cab can get without turning into a vibration box.
    kesslari likes this.
  7. Sounding good or bad with clipping comes down to individual amplifier design, not so much the class of the power section. Safe to say overdriving the power section of a solid state amp won't lead to the same pleasant results you'd get with a tube power section. Mind you, good or bad is also very subjective...
    jnewmark, wizard65, Loring and 5 others like this.
  8. Bad stereotype from the earlier days.

    Plug into a Mesa TT-800, WD-800, Genzler Magellan 800, Darkglass Microtubes 900, and you will hear great clipping.

    Light and loud is now a thing.
    All these are 6ish pound amps with 800ish watts, that is the great advantage to a Class-D design.

    P.S. If you have been to any medium to large music event in the last 10+ years you were hearing a Class-D amp pushing the PA.
    They are the industry standard now.
  9. kesslari

    kesslari Groovin' with the Fusion Cats Staff Member Gold Supporting Member

    Dec 21, 2007
    Santa Cruz Mtns, California
    Lark in the Morning Instructional Videos; Audix Microphones
    If you've been out of the scene for 10+ years you will be STOKED at how great an amp can sound (and how loud it can get while sounding great) while weighing less than many University textbooks :D
    Coot, Altitude, JRA and 22 others like this.
  10. Markbass make some great Class D amps.
    NEBADON2000, bulldean and BluesWalker like this.
  11. Class D is solid state.
    Solid state is without tubes.
    And yes you’re going to be amazed at what took place in the last 10 years.
    Welcome back to the low end!
  12. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    Only poor designs suffer from serious clipping artifacts. The world has evolved a lot from those Wikipedia days.
  13. 73_Blazer

    73_Blazer Supporting Member

    Jan 16, 2018
    Last edited: Jul 21, 2021
  14. dbsfgyd1


    Jun 11, 2012
    Mascoutah, IL
    You mean Wikipedia isn’t 100% gospel truth?? I’m shocked! LOL!!!
  15. kesslari

    kesslari Groovin' with the Fusion Cats Staff Member Gold Supporting Member

    Dec 21, 2007
    Santa Cruz Mtns, California
    Lark in the Morning Instructional Videos; Audix Microphones
    No. Much like "Most houses in a city use the same electric infrastructure so the only difference would be the number of outlet and the wattage of the bulbs" would be "no".
  16. Astronaut


    Jul 21, 2013
  17. Um... Class T isn't a real amplifier class. I think the company that coined it is out of business, aren't they?
  18. It's a supposedly superior variant of Class D, still in use by several major manufacturers. The original company (Tripath) went out of business. One of my little home-made Class D amps uses what is claimed to be a Class T circuit, although it's hard to tell...
    fdeck likes this.
  19. Old Fart

    Old Fart

    Mar 11, 2011
    Earth is a Class M planet. I hope that is helpful.
    groooooove, Kijuer, Luther and 21 others like this.
  20. Bassamatic

    Bassamatic keepin' the beat since the 60's

    I thought that MarkBass uses switching power supplies for super small and cool amps, but the output stage is still Class AB (at least in some).

    And to make it simple - transistors generate heat and distortion when they are operating in the area between fully ON and fully OFF. In a class D amp the output devices are turned Fully ON and Fully OFF very quickly (many thousands of times per second), so they don't distort or get very hot. To vary the amount of power, the circuit adjusts the amount of time they are left ON. Then at the output, all these wide and narrow pulses are smoothed out by running through a big coil. If you couple this with a SPS (Switching Power Supply) that kinda does the same thing in reverse, you get a real small, powerful, cool amp.