http://www.audioholics.comWhere audio and video equipment undergoes rigorous objective and subjective tests by our staff, ensuring that marketing slogans aren't the only guidelines for your home theater choices.Fri, 08 May 2009 04:05:00 -0000http://www.audioholics.com/education/amplifier-technology/class-d-digital-amplifierEver wonder how an amplifier works at a very fundamental level? Alan Lofft, Resident Expert of Axiom Audio takes us on a tour of traditional linear amplifiers as well as the newer more sleek Class D designs. Various types of Class D design approaches are discussed including feedback topologies and their implications on audio performance and efficiency. The similarities and differences of traditional Class D amplifiers compared to Axioms new A1400-8 multi channel amplifier is reviewed. Learn what makes these amplifiers tick and why it’s cool in more ways than one to get your hands on the future of high end audio amplification that is powerful, efficient, and lightweight compared to their analog predecessors. Fri, 08 May 2009 04:05:00 -0000/education/amplifier-technology/class-d-digital-amplifierAmplifier TechnologyAV Universityhttp://www.audioholics.com/education/amplifier-technology/clone-amplifiersIt’s been a few years since our controversial release of “Attack of the Clone Processors” and we felt it was time for a sequel to our blockbuster hit editorial. Engineering a product from the ground up, especially one as complex as a switching amp, takes time and money with the end result often not being as good or cost effective as what can be bought off the shelf like these ICE modules from Bang & Olufsen. I can count the number of manufacturers producing their very own Class D designs and still have a finger left to point at all the copycats. Overall this seems to be a good design approach for manufacturers unwilling or unable to do their own developmental work if cost and full disclosure of performance is kept in check. It’s up to you the consumer to decide if paying a premium price for name brand, exotic accessory parts and cosmetics is worth the investment. Just don’t let anyone tell you that regardless of price, you are buying anything other than a clone amplifier, albeit a reasonably well engineered one. Wed, 29 Apr 2009 02:12:57 -0000/education/amplifier-technology/clone-amplifiersAmplifier TechnologyAV Universityhttp://www.audioholics.com/education/amplifier-technology/amplifier-power-ratingsEver wonder why the boom box you bought at Best Buy has a higher power rating than your dedicated two-channel power amplifier? Amplifier power ratings are usually honest in Hi-Fi equipment, but become very silly when it comes to the 'mass market' systems and even some of the latest Class D amplifier offerings. Few amps have a dynamic headroom of better than 1 or 2dB, and the greater the headroom, usually the cheaper the power supply for the rated power. This article explores the history of power ratings for consumer audio and also busts the myth about 'RMS' power.Tue, 28 Apr 2009 03:06:36 -0000/education/amplifier-technology/amplifier-power-ratingsAmplifier TechnologyAV Universityhttp://www.audioholics.com/education/amplifier-technology/tradingWith new A/V receiver models being released by the major manufacturers every 8 months or so, consumers flock to them for promised improved performance and features. But are you really getting better performance with the newer models? Or are you trading amplifier quality for features? This article will be primer for what’s to come in our verification testing to better answer these questions. Stop and think if the model you currently have meets the performance vs feature balance that is right for your needs and how the newer so called “improved” model fits into that equation. All the features in the world can’t replace clean undistorted dynamics which we believe makes up most of the WOW and magic in the newer HD audio formats.Mon, 16 Mar 2009 19:57:24 -0000/education/amplifier-technology/tradingAmplifier TechnologyAV Universityhttp://www.audioholics.com/education/amplifier-technology/10-things-about-audio-amplifiersAlan Lofft, Axiom Audio's Resident Expert, took a series of the most commonly asked questions he received about amplifiers, and transformed his answers into an informative editorial. In this article you will find answers to the importance of amplifier weight and how it relates to quality, how an amplifier works, what the different classes of amplifiers are (ie. class A, A/B, D, etc), and the most important attributes of amplifiers that govern their real world performance. Thu, 18 Sep 2008 19:37:33 -0000/education/amplifier-technology/10-things-about-audio-amplifiersAmplifier TechnologyAV Universityhttp://www.audioholics.com/education/amplifier-technology/the-all-channels-driven-acd-amplifier-testCan Your Amp Truly Deliver What It Claims? Just how valid is the ACD test most home theater publications use to measure amplifier power? This article cuts through the nonsense of this hotly debated (and often misunderstood) topic.Tue, 18 Jul 2006 00:00:00 -0000/education/amplifier-technology/the-all-channels-driven-acd-amplifier-testAmplifier TechnologyAV Universityhttp://www.audioholics.com/education/amplifier-technology/switching-amplifiers-the-technology-and-the-issuesThis article started because a good friend of mine dropped a Panasonic SA-XR50 switch-mode amplifier to me for some basic bench test. This article will NOT be a review of that unit, but an investigation into some of the issues that are happening with this technology.Mon, 10 Apr 2006 00:00:00 -0000/education/amplifier-technology/switching-amplifiers-the-technology-and-the-issuesAmplifier TechnologyAV Universityhttp://www.audioholics.com/education/amplifier-technology/switching-amplifier-class-d-basics Just today I read on an internet forum a post by a "hot" new manufacturer of class D amplifiers saying that "the only way to solve the interference problem is to put the amplifier in a completely sealed metal enclosure". Apparently they were trying to excuse the fact that their product renders any nearby tuners useless. This begs the question: why didn't they do so then? Answer: because it doesn't help.Thu, 02 Mar 2006 00:00:00 -0000/education/amplifier-technology/switching-amplifier-class-d-basicsAmplifier TechnologyAV Universityhttp://www.audioholics.com/education/amplifier-technology/the-high-instantaneous-current-spec This very subject came up recently in the Audioholics forum and I would like to expand on this subject further, but before I do I think it's important to go into the history of how this specification became popular.Tue, 25 Oct 2005 00:00:00 -0000/education/amplifier-technology/the-high-instantaneous-current-specAmplifier TechnologyAV Universityhttp://www.audioholics.com/education/amplifier-technology/basic-amplifier-measurement-techniquesThere has been much discussion on many of the audio forums lately regarding mid priced A/V receivers power capabilities as well as their abilities to drive low impedance loads. Much of the controversy steams around the infamous " All Channels Driven Test " which simulates a best case test load in a worst case environment and by all intents and purposes an unrealistic real world scenario. For more information on this, the reader is encouraged to read the following articles: The All Channels Driven Test Controversy and Product Managing Receiver Platforms.Fri, 26 Nov 2004 00:00:00 -0000/education/amplifier-technology/basic-amplifier-measurement-techniquesAmplifier TechnologyAV Universityhttp://www.audioholics.com/education/amplifier-technology/product-managing-receiver-platforms-power-ratingsStereo reproduction in the fifties morphed from separates built by small high-end manufacturers like Saul Marantz to entrepreneurs like Sidney Harman who is credited with marketing the first receiver. Throughout the early sixties Harman-Kardon was joined by other American companies like H.H. Scott, Lafayette and Fisher until, toward the end of the decade, the Japanese joined the receiver category with lower cost receivers touting "innovations" like my (first receiver) JVC with a 5-band equalizer built-in.Tue, 09 Nov 2004 00:00:00 -0000/education/amplifier-technology/product-managing-receiver-platforms-power-ratingsAmplifier TechnologyAV Universityhttp://www.audioholics.com/education/amplifier-technology/the-all-channels-driven-amplifier-test-controversy There has been a lot of controversy on many of the Internet forums regarding power capability of receivers when driving multi-channel speaker systems. Some argue that when a receiver is rated at 100wpc x 7, it should be able to deliver this power to all channels simultaneously. But is this a realistic test condition and requirement to place on such a product whose aim is to provide the highest price/performance in a compact box for the typical consumer?Tue, 21 Sep 2004 00:00:00 -0000/education/amplifier-technology/the-all-channels-driven-amplifier-test-controversyAmplifier TechnologyAV Universityhttp://www.audioholics.com/education/amplifier-technology/damping-factor-effects-on-system-responseMuch ballyhoo surrounds the concept of "damping factor." It's been suggested that it accounts for the alleged "dramatic differences" in sound between tube and solid state amplifiers. The claim is made (and partially cloaked in some physical reality) that a low source resistance aids in controlling the motion of the cone at resonance and elsewhere.Mon, 30 Aug 2004 04:00:00 -0000/education/amplifier-technology/damping-factor-effects-on-system-responseAmplifier TechnologyAV Universityhttp://www.audioholics.com/education/amplifier-technology/audio-amplifier-classesThere are several basic classes of amplifiers in use today. Three of the more "audiophile of these are Class A, Class B, and Class AB. With the advent of additional digital amplifier technology this section will continue to be updated. Please stay tuned...Mon, 30 Aug 2004 00:00:00 -0000/education/amplifier-technology/audio-amplifier-classesAmplifier TechnologyAV Universityhttp://www.audioholics.com/education/amplifier-technology/the-truth-about-digital-class-d-amplifiers Firstly I'd like to point out that "digital amps" is a misnomer. There are two categories: Analog-controlled class D. Switching amplifiers…Mon, 30 Aug 2004 00:00:00 -0000/education/amplifier-technology/the-truth-about-digital-class-d-amplifiersAmplifier TechnologyAV University