Carvin weighs in on switching amps ...

Discussion in 'Amps and Cabs [BG]' started by pickles, Mar 4, 2006.

  1. pickles

    pickles Supporting Member

    Mar 23, 2000
    Ventura, CA
    I was thumbing through the new carvin catalog and noticed this section describing how conventional amps perform better than class H amps. Interesting. Seems to jive with Jim Bergantino's comments about "current reserve" and the ability of an amp to "finish a note".
  2. BassikLee

    BassikLee Supporting Member Commercial User

    Feb 13, 2004
    Deltona, FL
    Owner: Brevard Sound Systems
    look for another job. This one post is going to kill all of QSC's amp sales. Damn, I hope he, Pat, Brian, and the rest of them find work somewhere.....

    I, for one, have never found carvin power amps to be all that impressive.

  3. Eric Cioe

    Eric Cioe

    Jun 4, 2001
    Missoula, MT
    Carvin has been publishing this graph for years. QSC's sales have been fine.
  4. pickles

    pickles Supporting Member

    Mar 23, 2000
    Ventura, CA
    I'm not sure how this turned into a QSC sales discussion :eyebrow:

    Does anyone have anything to say about the validity of the test?
  5. svtb15

    svtb15 Commercial User

    Mar 22, 2004
    Austin,TX - McKinney,TX - NY,NY, - Nashville,TN
    I play it all. Whatever works for the gig
    I have a Carvin DCM amp that I got years ago. I originally got it to use as a studio monitor amp. But figured , let me try it on my bass rig paired with an Alembic F2B preamp. I was amazed at the punch it had and the low end that it kept through a sustaining note.
    I have since tried my friends QSC powerlight and it doesnt quite has the low end whoomf that the carvin has. The older heavy black face amps that QSC made , i think it is the MX1500 series where beasts.. But the Powerlights when AB with a Crown or Crest or low budget Carvin DCM does not have the low end I have noticed. My 300 Watt SVT has more punch and roundness with reserve bottom end than the higher powered Powerlight amps I have observed. My first experience with a light switching power amp was back in the 1980s when I went from using my alembic preamp into a BGW750 or my Crown PSA2. I was moving my own gear and wanted something lighter. Carver came out with their PM1.5. It may be good for a mid pack in a PA but not for bass. The amp just had no bottom at all. I guess it looked good on paper..
    I think the power lights are way better than the Carver not Carvin amps by a mile. But in my opinion nothing beats a power amp with a big power supply for big bottom bass.. Look at the power amp section of the Aggy db750.. it is a monster. That is where all that reserve comes from.. big caps and transformer with a seafull of power to be released on command. I don’t think the Carvin stacks against the Crest Audio or Crown Macro Series. The Powerlights are a good amp but I think the Carvin from my AB test has better un EQed low end for bass guitar.
  6. seamonkey


    Aug 6, 2004
    I think the key phrase is "Most of our competition"
    If you look at other amps in the same price range as Carvin that also claim to be Class-H then I'd suspect the power supply wasn't up to the task. It may not have enough capacity.

    This isn't a fault of "class" of the amplifier. More a fault of the power supply design.

    You'll see that the lower price "competition" won't have wattage ratings listed with "RMS" or "EIA" - it'll be unqualified wattage.
  7. lowmid1


    Aug 16, 2002
    Baltimore, MD
    I think some people are getting confused with regard to "class of operation" and "type of power supply". Class H refers to an amplifier with multiple voltage rails for the output devices. It has nothing to do with the type of power supply.

    Carvin's amps are all "class AB" with conventional power supplies which require more heatsink and cooling, especially at higher power levels. They also contend that "class H" operation requires less heatsinks and cooling and is sonically inferior to class AB. This means that the "fabled" Crest CA-9 which is a class H amp should be sonically inferior to a DCM 2000 because the DCM 2000 is a class AB amplifier.

    Also, Jim Bergantino's posted comments suggested that amps with Switch Mode power supplies were sonically inferior. He made no mention of class of operation. In fact, the amp he was recommending was a CA-9 which is class H.
  8. seamonkey


    Aug 6, 2004
    Yep - any class of amp can have a switch mode power supply (SMPS) or a traditional linear power supplies.

    There's nothing inherently wrong with either type of power supply.
    And any type of power supply can be under designed for the amp.

    An inadequate power supply in any class of amp would look the same as the class-h in Carvin's diagram. And it may be the manufacturer is rating their amp at peak power, and thus pushing the limits of the amp in the test.

    In any case, the class of the amp doesn't have anything to do with this test. It's more about the power supply in the amp being able to keep up.
  9. +100
  10. lowmid1


    Aug 16, 2002
    Baltimore, MD
    Unless I am reading this incorrectly, Carvin is inferring that "class H operation" is inferior. They mention the "mid-band switching distortion" that occurs when the output devices switch from the low voltage supply rail to the high voltage supply rail and they also say that "the only way to have 100% on demand power is to have full voltage on the output devices all the time.........which is class AB operation"

    They are talking about "class H operation", not inadequate power supplies.
  11. Passinwind

    Passinwind I Know Nothing Supporting Member

    The test they "invented" corresponds to full power kick hits at a tempo of least 1000 beats/minute. Anyone else find that a little fishy? If not, can I have your drummer's number?
  12. fdeck

    fdeck Supporting Member Commercial User

    Mar 20, 2004
    Madison WI
    HPF Technology LLC
    They are also wrong. But why are we trying to read anything into Carvin's marketing hype? Mid-band switching distortion should be measurable, right? Why not just look at the distortion specs?
  13. Plain Old Me

    Plain Old Me

    Dec 14, 2004
    I thought only class B had full power on the output at all times- not AB. In any case, I havn't noticed significant sonic difference between the classes of amps specifically- there are other factors which make more of a sonic difference.
  14. lowmid1


    Aug 16, 2002
    Baltimore, MD
    We aren't! (reading anything in to the marketing hype) I just noticed that there appeared to be some confusion as to what the marketing hype was actually referring to and was attempting to clarify that for the confused.

    As far as the mid band distortion goes, theoretically it seems like it should exist but I have never been able to discern that by listening and I have 3 class H amps. (Ca-9,RMX 2450 and PL236) So to me it is irrelevant.
  15. lowmid1


    Aug 16, 2002
    Baltimore, MD
    I think that might be class A, not B. It is my understanding that when producing higher powered amps. class H becomes desireable because less energy is wasted as heat, requiring less thermal management and reducing cost and weight. I haven't noticed any difference either so I don't pay much attention to any of the hype.
  16. MTD Man

    MTD Man

    Jun 12, 2004
    Yeah!! I bet this drummer could give Virgil Donati a run for his money...

    I remeber a virgil solo video:
    audience: "200!!" (bpm)
    Virgil: "Give me a chance... 190"

    Chris | dang
  17. Petebass


    Dec 22, 2002
    QLD Australia
    Jim seems to have turned 180 on his previous views anyway. In the past he's suggested only heavy amps with heavy power supplies worked well enough for his tastes. If that was still the case, new IP series wouldn't exist.

    Like anything, time delivers improvements. The first switching power amps may have indeed been crap, but that was then and this is now.
  18. seamonkey


    Aug 6, 2004
    Speaking of hype - here's some of Yamaha's - it's a fun read:

    Some quotes:
    "Class H is not intended for music signals with wide dynamic ranges."

    BTW: There are a couple of ways to do class-h, so maybe Carvin tested a bad amp anyhow.
  19. seanm

    seanm I'd kill for a Nobel Peace Prize! Supporting Member

    Feb 19, 2004
    Ottawa, Canada
    According to EA's marketing literature, this is what gave class D amps a bad name. Early designs had insufficient switching power supplies. People associated switching power supplies with class D when, like others have said for class H, the power supply has nothing to do with the class of amp.
  20. lowmid1


    Aug 16, 2002
    Baltimore, MD
    The thing I can't figure out is why all the misleading "tests"? The carvin amps are good amps and don't need any marketing hype.