Receiver and Amp Power Ratings Over the Past 50 Years

Discussion in 'Amps, Pre-Pros & Receivers' started by admin, Jul 19, 2013.

  1. admin Audioholics Robot Staff Member

    admin
    Joined:
    Apr 16, 2004
    Messages:
    172
    Likes Received:
    1,612
    Over the years, AV receiver manufacturers found ways to rate power less conservatively to give the illusion of more.

    We all know this, we see it all the time.

    But how did this trend start? Why does it persist? And how do manufacturers manipulate the reads?

    Maybe most importantly, how can you identify these tricks?

    Note - This article was originally published in 2004. We refreshed and an republished because it's such an awesome piece.

    [​IMG]

    Read the full article: AV Receiver and Amplifier Power Ratings and Trends: How and Why Wattage Ratings are Manipulated
    • Like Like x 2
  2. M Code Full Audioholic

    M Code
    Joined:
    Oct 26, 2009
    Messages:
    468
    Likes Received:
    149
    Location:
    Joshua Tree, CA
    One significant point not mentioned is that the original FTC amplifier specifications developed in 1973 used the word Minimum in their power output statement..
    So that the receiver's average power output, would be significantly higher by 10-15%, also typically the amplifier highest output power is @ 1KHz, while @ 20Hz and 20kHz power would be lower. And if the receiver was more of budget category and lower priced, it low frequency response bandwidth was limited to 40Hz due to a smaller power supply.

    In consumer electronics, there are multiple electrical performance specifications and these are usually called Limit and Design Center/Nominal. The Design Center/Nominal specification are the target specifications used by the design engineer considering the tolerances (and costs) of the various, internal electrical components. The Limit specification was the minimum value that the unit would need to meet to pass the production standards. This is an area where many brands would play games, for power output they would publish the Design Center specification which was 20-30% higher than the Limit specification. A couple of brands such as Harman/Kardon and Marantz would publish the Limit power output specifications thats why in many instances they were lower than the competition.

    Fast forward to now..
    Though there is a power output statue for receivers and amplifiers @ least in the USA but there is no monitoring to its adherence so certain mass-oriented receiver brands tend to tweak/stretch to higher numbers as to drive sales through price-only internet sellers and build sales.. In certain instance teh power output specifications are craeted by teh marketing/advertising groups rather than the engineering team. The best bet to get reasonable, realistic power output specifications is to stay with the established brands who base their products and design on other attributes rather than just a higher power output number.


    Just my $0.02.. ;)
    • Like Like x 2
  3. Irvrobinson Audioholic Ninja

    Irvrobinson
    Joined:
    Dec 7, 2004
    Messages:
    3,180
    Likes Received:
    1,315
    The Marantz 2270 described in the article was relatively powerful for its day at 8 ohms, but power fell off and distortion rose at 4 ohms. It is a poor example to use of conservative design and ratings. It looked nice though, and the tuner was pretty good; I owned a new one.
  4. M Code Full Audioholic

    M Code
    Joined:
    Oct 26, 2009
    Messages:
    468
    Likes Received:
    149
    Location:
    Joshua Tree, CA
    What graphs are you looking at.. :confused:
    The 2270 amplifier circuit was quite robust...
    Yes the THD would increase when driving a 4 Ohm vs. an 8 Ohms load but still remained < 0.1% up to 100 watts..
    One thing to keep in mind..
    What test equipment was used to measure THD, back then THD measurements were made with either an HP221C or a Sound Technology 1700..
    Crazee thing is that each of those had a residual noise floor of >0.1%, so the analyzer would read itself rather than the amplifier being tested..
    Any THD% was included with the 0.1% noise floor, accurate THD measurements (<0.05%) were not available until the Audio Precision systems became available..

    Just my $0.02... ;)
    • Like Like x 1
  5. Irvrobinson Audioholic Ninja

    Irvrobinson
    Joined:
    Dec 7, 2004
    Messages:
    3,180
    Likes Received:
    1,315
    I've been through this before, with you. Remember? http://forums.audioholics.com/forums/amps-pre-pros-receivers/81494-vintage-pre-amps-new-amps.html
  6. avengineer Banned

    avengineer
    Joined:
    Nov 21, 2012
    Messages:
    272
    Likes Received:
    82
    Location:
    $ cd ~/Earth/North America/USA
    HP 334A introduced in 1968 would read .1% full scale, down to .01% residual. The Tektronix AA501 would go to .001% with the SG504 oscillator as the source. The Tektronix 5L4N spectrum analyzer (early 1970s) had enough dynamic range to read THD (and separate it from N) well below 80dB. All pre-dated AP, and if I recall correctly, the founders of Audio Precision worked at Tek on the AA501 and related devices first, then left Tek to start AP.
  7. scott911 Full Audioholic

    scott911
    Joined:
    Nov 28, 2007
    Messages:
    280
    Likes Received:
    30
    independent group

    It would be interesting to have an independent group step in and publish a true & consistent power rating for popular models. Almost like a horsepower to the wheels measurement.
  8. Irvrobinson Audioholic Ninja

    Irvrobinson
    Joined:
    Dec 7, 2004
    Messages:
    3,180
    Likes Received:
    1,315
    That's already done, they're called product reviews.
  9. 3db Audioholic Overlord

    3db
    Joined:
    Sep 7, 2002
    Messages:
    10,562
    Likes Received:
    2,489
    Location:
    Ottawa Canada
    Yes but many reviews do not measure power the same way and IHO, those that do provide graphs use methodologies that are far from real life or accurate.
    3db,
  10. plhart Audioholic

    plhart
    Joined:
    Feb 10, 2004
    Messages:
    189
    Likes Received:
    8
    A surprise blast from the past

    Hi Gene-

    What a surprise to see Audioholics reprint one of my old articles. Thanks!

    Patrick Hart
  11. PENG Audioholic Warlord

    PENG
    Joined:
    Oct 23, 2004
    Messages:
    7,902
    Likes Received:
    2,206
    Location:
    Ontario
    The article is a good read but we need a nice one on the THD+N from 0 to say 100W that I think will affect most people. For me I actually need to see the specs at the 0.05 to 2W range as most of the time I listen to spl that only needs fractional watt from my amp(s). It will be tough to find articles on this topic that are back with facts and tested fugures. So far I have only been able to find one site that offers a decent library of lab measurements for amps that include THD+N data for down to 1 watt, but not lower. HTM's graph kind of does go down to zero but the resolution of the graphs presented are just not good enough to be taken seriously. Besides, the reviewer don't ever talk about figures at such low output level and that led me to believe they don't take those graphs (at the low end) seriously either, but they should. I know Irv will probably agree with me on the importance of the first watt and below because if I remember right he, or Rich have brought that issue up before.
    PENG,
  12. gene Audioholics Master Chief Administrator

    gene
    Joined:
    Jul 1, 2002
    Messages:
    7,533
    Likes Received:
    3,259
    Location:
    Florida
    Hey Pat. It was a classic and needed to be dusted off the shelf and brought back to the limelight. Glad to see you still lurking here and miss your contributions to the site. Hope you are well my old friend.
    gene,
  13. Irvrobinson Audioholic Ninja

    Irvrobinson
    Joined:
    Dec 7, 2004
    Messages:
    3,180
    Likes Received:
    1,315
    You're darn tootin' I'll agree with you, because I have brought it up before. It is unfortunate, however, that the audio reviewer who coined the term "first watt", Richard Olsher, is also the person who really started the high-end cables-have-an-intrinsic-sound movement when he worked for Stereophile. Worse yet, Olsher is a physicist and should know better. Anyway, I suppose even snake oil promoters can have good ideas now and then. Nelson Pass liked the first watt concept so much he named a company after it, where he produces specialty amplifiers. (Imagine a guy so unconventional he thinks Pass Labs is a mainstream audio manufacturer, and he needs a separate company for really esoteric stuff... :) )
    • Like Like x 2
  14. avengineer Banned

    avengineer
    Joined:
    Nov 21, 2012
    Messages:
    272
    Likes Received:
    82
    Location:
    $ cd ~/Earth/North America/USA
    Care to cite a specific on this?

    The traditional way to measure maximum amp power is to load the amp with a known load and drive it to clipping, then back off until the distortion drops below 1%, measure the voltage, and calculate power (or let the software just do it).

    The only variables would be measuring power over frequency, or power over time (dynamic headroom).
  15. gene Audioholics Master Chief Administrator

    gene
    Joined:
    Jul 1, 2002
    Messages:
    7,533
    Likes Received:
    3,259
    Location:
    Florida
    gene,
    • Like Like x 1
  16. Splicer Audiophyte

    Splicer
    Joined:
    Jan 13, 2013
    Messages:
    9
    Likes Received:
    3
    Gene, I just wanted to say THANKYOU for pretty much vindicating me on AVS. For years I have been 'complaining' that the marketing used on these lower (and sadly, upper as well) end subs always stating '1000 watts!' (as an example) and always been chastised for doing so. But as you said in the video, look at the fine print to see the REAL numbers. The inflated, unusable and unrealistic numbers provided anymore are no more than marketing snake oil. Sort of like directional cables but I digress.

    Just wanted to say thanks, I enjoy all of the Audioholic videos and the friendly bantar that accompanies them.
  17. gene Audioholics Master Chief Administrator

    gene
    Joined:
    Jul 1, 2002
    Messages:
    7,533
    Likes Received:
    3,259
    Location:
    Florida
    I appreciate your compliments. We are here to cut through the nonsense in marketing which sometimes makes us unpopular with the manufacturers and the fanboys too. At the end of the day, we share a common goal, a better audio experience without all the fluff. Hope you can participate more on this forum too.
    gene,
  18. highfigh Audioholic Spartan

    highfigh
    Joined:
    Sep 14, 2008
    Messages:
    7,208
    Likes Received:
    1,742
    Location:
    Milwaukee area
    BPI had some distortion analyzers, too. IIRC, we had the 3000 at the store where I worked.
  19. vinod.r Audiophyte

    vinod.r
    Joined:
    Feb 11, 2011
    Messages:
    3
    Likes Received:
    2
    Hi Guys,

    JEITA - Japanese Electronics Industries Trade Association.

    It is another way of rating which is followed in products in Japan. Please correct me if I am wrong.

    Vinod
  20. Deep Ear Audiophyte

    Deep Ear
    Joined:
    Jan 23, 2015
    Messages:
    4
    Likes Received:
    2
    Over the years, AV receiver manufacturers found ways to rate power less conservatively to give the illusion of more.

    We all know this, we see it all the time.

    But how did this trend start?


    Gene-

    What I recall happened when I became Yamaha's Product Manager in 1983 (from Kenwood Car Stereo) was as follows:

    The Japanese audio manufacturers had all just decided to standardize component widths to 430-435 mm while mini component width which was common in products in Japan and I think the European market at the time was standardized at 350 mm. With this move the gargantuan high power receivers like the popular Sansui 5000 which dominated military exchanges all of the world ceased to be produced. So all manufactures were now tasked with getting (true RMS) higher power out of this much narrower, standard receiver width.

    Second, Yamaha was really concerned with meeting UL specs because they and all their competitors were trying to come out with and market what they wanted the American audio consumer market to believe were proprietary amplifier typologies that "sounded better" than their competitors. For instance, Yamaha came out with a pyramid shaped amplifier with "X-power". But unfortunately X-power was based on Bob Carver's small 200 Watt per channel 6" x 6" x 6" cube topology. So I recall the bottom line with X-power was Yamaha's US-based certification engineer (named Lucky, no joke) told me at one time he had blown up 25 pre-production prototype amps Yamaha, Hamamatsu, Japan had sent him, none would pass UL.

    Next, Yamaha Japan started asking me about the old IHF, Institute of High Fidelity power specs that Julian Hirsch (deceased) of Stereo Review followed which is essentially the same 20Hz - 20kHz, 8 ohm @ 0.XX% spec (at that time in the late 60's and early seventies still called cycles per second) that you are trying to get back to now. Yamaha's engineers told me they were having a really hard time meeting the full 20 Hz to 20 kHz bandwidth power spec at 8 ohms, how about if they used 6 ohms, would that be okay for our U.S.-only receivers? In the same breath they promised they would keep the 8 ohm 20 Hz to 20 kHz full bandwidth spec for Yamaha's integrateds and separates which were sold world wide.

    It has been decades since Yamaha receivers first wowed specialist audio dealers (six hundred selling Yamaha at the time) and baby boomer audiophiles like me when introduced in the early seventies. At that time (wide and deep) Yamaha receivers stood alone against lesser manufacturers products which claimed 500 watts!, 1000 watts!. The power amplifier ratings game cycle as you have so astutely observed has sadly come all the way back to where we were then.

    The one good piece of news I can share Gene is that when I began designing speakers for Marantz in Sun Valley, CA in 1971 Dawson Hadley (deceased) Marantz's chief engineer of American-built integrated's and separates started me off wiring the internals of my prototype speaker designs with twisted 14-gauge wire, a trick he had learned from JBL's Bart Locanthi (deceased). Physics don't change, but sadly a new generation of snake oil sales and marketing slubs seem to be ever-present. Sigh...
    • Informative Informative x 1

Share This Page

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