Class A/B Home THeater Receivers

Hi Bruce,

There are plenty of great Class A/B AVR's with HDMI inputs, as well as all the latest codecs and features (Dolby Atmos, DTS-X, HDCP2.2 for 4K and HDR support, etc.), from manufacturers like Denon, Marantz, Yamaha, as well as more high tiered brands like Arcam, NAD, etc., so there is no need to despair. :)  I sent you a PM with our contact info, and would be happy to help in any way I can.

Take care,

-David

Hi David,

I understand that Bruce prefers a class A/B AVR because that’s what he’s always used and he’s comfortable with this traditional technology. Unfortunately, he seems to have gotten some false information that class D technology has had reliability issues and he generally seems poorly informed on the numerous advantages of class D. To be fair, this is likely due to Bruce having little to no exposure to class D.

My view, based on research and personal experience, is that switching from all class A/B amplification to all class D amplification results in superior performance in all areas that audio enthusiasts care about such as a lower noise floor, lower distortion levels, better bass response, greater dynamic range and generally coming closer to the audio ideal of a ’straight wire with gain’. There’s also other benefits not directly related to sound quality such as smaller size, less weight, affordability, no heat sinks required,less heat emitted, significantly higher efficiency and reduced electricity usage. To further tip the scales, all these benefits are gained with zero costs or negatives that I’ve become aware of during the past 2 yrs I’ve used class D amps.

So, as the owner of an A/V company, I’m interested about your views on class A/B vs class D amps and just have a few questions if you’re willing:

1. Do you recommend class A/B to all your customers?

2. Can you name any important performance measure or quality in which class A/B is superior to class D?

3. Can you name any important performance measure or quality that could be in any way accurately be described as a cost, ’negative’ or sacrifice of switching from class A/B to class D? I honestly cannot.

4. Have you ever compared one of your popular A/V systems using all class A/B amplification to the identical one using all class D amplification? If so, can you share the results?

5. Does your company even carry or sell any class D amps or receivers?

I’m not familiar with your A/V business but I’m fairly sure you have extensive experience in selling and installing many A/V systems. Because of this, I’m sincerely interested in your viewpoint.

Thank you,
Tim

Bruce,

  You stated:

" I actually thought the Class D sounded a little cleaner and more detailed... but then I started researching customer reviews of those AVR, and I was surprised to fin that there are TONS of technical problems, and outright failures, of the Class D amps."

     Tons of technical problems with class D amps?

    First I've heard of this, I hope you're not a believer in 'alternative facts' ala Kellyanne Conway.


Tim

I’ve been using a class D amp to drive large floorstanders loudly for 3 years with nary a hiccup. I’m actually looking to upgrade to monoblocks.. Class D of course.

Sure they can break, but so can class A and A/B. I’ve also never heard of higher rates of failure for class D as a whole. But maybe it was one particular receiver that had these problems..? Not all class D. Just throwing that out there.

toddverone,

Good points about all types of amps can break and that Bruce may have been reading about a particular AVR model that had repeated issues.

I’ve been running 3 class D amps (a pair of mono-blocks and 2 stereo) left on 24/7, and often played at high volumes, for a couple years now without any problems. They don’t even get any warmer than luke-warm no matter how hard they’re driven.

There seems to be a lot of anti-class D bias being spread along with some false information. My theory is that class A/B amp makers, sellers and biased fans may be the impetus behind this.

I believe Class A/B amp makers and sellers justifiably feel threatened. Class D already clearly equals or betters class A/B in every audio performance criteria along with every other criteria that is important to amp buyers such as price, size, weight, reliability, operating temperature and efficiency. I honestly cannot think of a single advantage that A/B has compared to class D.
In my opinion, class A/B amps have managed to remain viable longer than they merit for a few reasons:

1. Class D amps are mainly sold internet-direct with free or low cost in-home trial periods. Many potential customers are either unaware of this or reluctant to shop or buy via this method. This is slowly changing as more class A/B amp makers, concerned with their company’s future, are offering class D amps of their own that are sold through traditional stores.

2. Some, such as the OP Bruce, either have a bias against class D or mistook anti-class D info as truthful and decided to not even consider class D.

3. Not all amp buyers, being less knowledgeable than those active on audio blogs, even know of the existence of class D and its extraordinary attributes. The awareness of class D by this group is likely to only grow since there are so many ways (friends and family, chance reading or listening) to become aware that only increase over time.

As if the above wasn’t enough bad news for class A/B amp makers and sellers, they realize that their technology has peaked while class D technology is likely to continue to improve and only widen the performance gap.
It may be hard to believe, given my admittedly pro-class D bias described ad nauseam above, but I have no financial interest in the manufacturing or selling of class D amps. I’m just a big fan based on research, the facts and my experiences switching from all class A/B amps to all class D amps over the past few years.

I could go on but I’m going to bed,
Tim