Class A/B vs Class D amp comparisons

Discussion in 'Amps, Pre-Pros & Receivers' started by padgman1, Sep 20, 2013.

  1. padgman1 Enthusiast

    padgman1
    Joined:
    Apr 4, 2013
    Messages:
    16
    Likes Received:
    2
    Have there been any FORMAL blind comparisons between Class A/B amps (reasonably priced ones like Outlaw/ATI/Emotiva, etc.) and Class D amps ( Crown, Rotel, D-sonic, Wyred 4 sound, etc) showing difference in sound quality/qualities ?

    If there are little perceived differences in sound quality, why would one purchase a more expensive amp than any of the Crown XLS series of amps( besides needing multiples for a 5way or 7way system)?
  2. jinjuku Moderator

    jinjuku
    Joined:
    Apr 6, 2007
    Messages:
    5,264
    Likes Received:
    1,679
    Location:
    Louisville, KY
    No tests that I know of. People make purchases all the time with criteria that isn't germane to the actual purpose of the product.
  3. RichB Audioholic General

    RichB
    Joined:
    Jul 22, 2005
    Messages:
    1,393
    Likes Received:
    277
    This is what worries me.
    AH did an in detail review of the Axiom Audio class D and it had some issues.

    When I looked on Home Theater HiFi (secrets) many class D's no measurements.

    Even the new D-Sonic class D's were just reviewed. No measurements.
    Do the manufacturers ask for no measurements, do they skip them because their equipment does not operate with them, or something else?

    I tried a D-Sonic ICE version and did not like the bass with my Salons.
    I think that the AH review of the Axiom shows similar results.

    - Rich
  4. ImcLoud Audioholic Ninja

    ImcLoud
    Joined:
    Aug 21, 2012
    Messages:
    4,767
    Likes Received:
    1,278
    Location:
    N.E. CT
    I think there are going to be some big steps in putting class d in home theater in the near future... I like the pioneer d3 stuff and wish they would make some separates, I would be a buyer for sure.... I like class a/b for all around amplification, not super expensive, sounds good, and seem to last long and not mind long run times... I like class t tripath designs for sound quality all around mids and highs sound awesome with tripath amps..
  5. Steve81 Audioholics 5-O

    Steve81
    Joined:
    Aug 9, 2012
    Messages:
    4,025
    Likes Received:
    2,060
    Location:
    38.89°N, 77.01°W
    Here's one set of measurements for an older Rotel:
    Rotel RB-1092 Stereo (500 Watts/Channel) Class D (Switching) Power Amplifier - Secrets of Home Theater and High Fidelity
    and some for a Pioneer:
    Pioneer SC-57 9.1 A/V Receiver - Secrets of Home Theater and High Fidelity

    As for AH, Gene has benched at least one Pioneer:
    Pioneer SC-07 Measurements and Analysis | Audioholics

    and from the AH Facebook page, he's got a IQ Audio M300 in house which seems to have impressed him on the bench thus far.
  6. RichB Audioholic General

    RichB
    Joined:
    Jul 22, 2005
    Messages:
    1,393
    Likes Received:
    277
  7. padgman1 Enthusiast

    padgman1
    Joined:
    Apr 4, 2013
    Messages:
    16
    Likes Received:
    2
    I see in many posts on this and other forums where a majority of people use some sort of Class A/B amp but that a significant minority are starting to use Class D amps with little PERCEIVED ( key word here) difference in sound quality..........

    For those who have tried BOTH, which do you prefer ( and "why")?
  8. fuzz092888 Audioholic Warlord

    fuzz092888
    Joined:
    Feb 13, 2012
    Messages:
    8,524
    Likes Received:
    4,116
    Location:
    42.3464° N, 71.0975° W
    I prefer neither. Between a well designed class A/B amp (Outlaw, Aragon, Perreaux, Cinepro, Rotel AB International) and a well designed class D amp (Crown XLS2500) I don't hear very much difference at all, or at least any differences I've heard could most likely be contributed to the comparison not being blind. However, I felt I heard more of a difference between the Threshold and the Crown, with a preference toward the Threshold (which is Class A to 50 watts). The Threshold seemed to give more oomph to the lower end, and a slightly warmer smoother presentation. Again, it wasn't blind.

    For a totally active system, which would require 4+ channels of amplification I would have zero problem going with 2+ Crown XLS amplifiers.
    • Like Like x 1
  9. M Code Senior Audioholic

    M Code
    Joined:
    Oct 26, 2009
    Messages:
    511
    Likes Received:
    158
    Location:
    Joshua Tree, CA
    The more recent Class D solutions are sonically superior to the early ones..
    The later solutions from Crown/TI, ICE, IR and D2/Intersil have addressed many of the early issues... Plus the higher performance of the hex-fet output devices...
    We have done a number of Class A-B vs. Class D solutions listening tests for some of the major audio brands for their golden ear listening panels.. Few could differentiate between these, but still there remains some opposition to change..
    But change will come as the advantages of Class D for size, form factor, watts/$, efficiency and cost will win the market over as it has already done in the OE automotive, personal, multi-media and home theater subwoofer categories...

    Just my $0.02... ;)
    • Like Like x 1
  10. Ampdog Audioholic

    Ampdog
    Joined:
    Aug 24, 2006
    Messages:
    169
    Likes Received:
    32
    Location:
    Pretoria, South Africa
    Padgman1,

    I unfortunately cannot speak from experience (and if I could, that would still only represent my perceptions .,..).
    But perhaps a warning in general: From technical experience, it is unfortunately so that in any class of amplification designs do differ (sadly with the inevitable short-cuts to gain a dime of profit), so that it is difficult to judge the merits of a particular topology simply by a few exponents. Thus I can say that, technically, there is no reason why in future class-D should not gain the upper hand cost- and convenience-wise, while returning the same fidelity (quality, lest taste should come into the mix) as analogue models, if not doing so already.

    This does not help you very much at present! But at least be alerted to study a number of comments from considered sources before making a conclusion based simply on the results from this amplifier or that.
    • Like Like x 1
  11. Mkegreg Enthusiast

    Mkegreg
    Joined:
    Oct 24, 2013
    Messages:
    13
    Likes Received:
    2
    From my listening tests, (Peachtree Nova125 vs. Marantz PM8004 through Paradigm Studio 20s) the Peachtree sounded a bit brash and inaccurate. I couldn't quite point it out, but to my ears it was unnatural. Maybe it's because my 42 YO ears have been taking in older tech amps all this time? The Marantz was much warmer, cleaner, and more accurate. I'd like to take and nice clean class A/B and match it with the NovaPre and see what happens......
  12. jinjuku Moderator

    jinjuku
    Joined:
    Apr 6, 2007
    Messages:
    5,264
    Likes Received:
    1,679
    Location:
    Louisville, KY
    I've heard more than a few complaints about Peach Tree products. Enough to make me wonder if the engineering overall is suspect.
  13. slipperybidness Audioholic Ninja

    slipperybidness
    Joined:
    Jul 24, 2011
    Messages:
    4,177
    Likes Received:
    923
    I've been considering a different take on the AB vs D debate and wanted to throw this out here.

    "Most" studio monitors are powered/active designs. I'm also guessing that most active monitors are powered from class D amps due to the need to shove the amps inside the speaker cabinets. Studio monitor design choices typically focus on the most accurate sound reproduction. Therefore, I would suspect that this is pretty good fuel to the fire that class D amps are not inherently inferior to AB topologies.
  14. Mkegreg Enthusiast

    Mkegreg
    Joined:
    Oct 24, 2013
    Messages:
    13
    Likes Received:
    2
    I look at studio monitors as rather bland, flat and void of any kind of character, as they should be. Colorless with no real soundstage. Otherwise, we'd all be using them in our homes I would think. The reason so many different configs, brands, and interpretations of home audio speakers exist is because each angle taken is a different color and people have their color preferences. Some like the color of B&W, others Paradigm, PSB, DIY, Salk...it's all about finding your favorite color.......or it could just be the whiskey talking.
  15. fuzz092888 Audioholic Warlord

    fuzz092888
    Joined:
    Feb 13, 2012
    Messages:
    8,524
    Likes Received:
    4,116
    Location:
    42.3464° N, 71.0975° W
    I would call that pretty inaccurate. The more likely reason is that studio monitors often fall short aesthetically, don't come with grills, and often are powered, which means multiple power cords to spots that would probably be awkward to get power to.

    There are accurate speakers and there are inaccurate speakers. While all speakers undergo a final voicing, in addition to the different drivers and cabinets, which all contribute to the "sound" of the speaker, the bottom line is that accurate speakers will sound more alike than different. More importantly, to some, is that the more accurate speakers will remain true to the source and trumpets will sound like trumpets, massed strings will sound like they should, etc. Let's also not forget about the room each speaker is heard in as well. The environment will contribute heavily to the way a speaker sounds when it is heard as well.
    • Like Like x 1
  16. Mkegreg Enthusiast

    Mkegreg
    Joined:
    Oct 24, 2013
    Messages:
    13
    Likes Received:
    2
    I've hung out at quite a few studios/sound rooms, I guess I never really felt that any of them had monitors that really made me go "wow!". We all have tainted ears, I might buy speakers that have an accurate guitar sound, because I'm a guitar player and I know what that sounds like to me, whether it be Hendrix or Bream. That same speaker that I love might be sub par at having an accurate trumpet sound, but wouldn't really annoy me as a non-trumpet player because I don't have that ear.... it's probably close enough for me.
  17. fuzz092888 Audioholic Warlord

    fuzz092888
    Joined:
    Feb 13, 2012
    Messages:
    8,524
    Likes Received:
    4,116
    Location:
    42.3464° N, 71.0975° W
    If the two sources are a well recorded guitar and a well recorded trumpet an accurate speaker will sound like a guitar and a trumpet. It doesn't make any sense to say a speaker will reproduce a guitar accurately and it won't reproduce a trumpet accurately. Either the source and the speaker are accurate or they aren't.
  18. Mkegreg Enthusiast

    Mkegreg
    Joined:
    Oct 24, 2013
    Messages:
    13
    Likes Received:
    2
    I'm not going to argue. All I'm saying, I am more skilled at picking out a speaker that reproduces the sound of a guitar accurately than the sound of a trumpet. I'm sure a trumpet player can do a much better job of picking out a speaker that is accurate at reproducing a trumpet. We could be on opposite ends of the spectrum in our choice of speakers simply in the way they reproduce our preferred instrument.
  19. fuzz092888 Audioholic Warlord

    fuzz092888
    Joined:
    Feb 13, 2012
    Messages:
    8,524
    Likes Received:
    4,116
    Location:
    42.3464° N, 71.0975° W
    Based on what you just said, the point I tried to make went whizzing by you. ;)
  20. jinjuku Moderator

    jinjuku
    Joined:
    Apr 6, 2007
    Messages:
    5,264
    Likes Received:
    1,679
    Location:
    Louisville, KY
    I've installed quite a few studios. I did a lot in the days when disk based NLE DAW was just coming into play. There are a lot of nice studio monitors that I would take over PSB (and I like PSB voicing), Paradigm, B&W.

    Genelec, JBL, Tannoy just to name a few. You may not have heard all there is to hear in the studio space.

Share This Page

  • EMPTek.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
  • CEDIA