Can someone direct me to a good source to get a better understanding of the differences in Class A, A/B, & D amplifiers? I thank you in advance.
My NAD 3020 D proves your Class D tropes are wrong
I have a desktop integrated, the NAD 3020D which I use with custom near field monitors. It is being fed by Roon via a Squeezebox Touch and coaxial digital.
It is 5 years old and it sounds great. None of the standard myths of bad Class D sound exist here. It may lack the tube like liquid midrange of my Luxman, or the warmth of my prior Parasound but no one in this forum could hear it and go "aha, Class D!!" by itself, except maybe by the absolute lack of noise even when 3’ away from the speakers.
I’m not going to argue that this is the greatest amp ever, or that it is even a standout desktop integrated. All I am saying is that the stories about how bad Class D is compared to linear amps have been outdated for ages.
Great to see new development with GaN based Class D amps, great to see Technics using DSP feed-forward designs to overcome minor limitations in impedance matching and Atmasphere’s work on reducing measurable distortion as well but OMG stop with the "Class D was awful until just now" threads as it ignores about 30 years of steady research and innovation.
It is 5 years old and it sounds great. None of the standard myths of bad Class D sound exist here. It may lack the tube like liquid midrange of my Luxman, or the warmth of my prior Parasound but no one in this forum could hear it and go "aha, Class D!!" by itself, except maybe by the absolute lack of noise even when 3’ away from the speakers.
I’m not going to argue that this is the greatest amp ever, or that it is even a standout desktop integrated. All I am saying is that the stories about how bad Class D is compared to linear amps have been outdated for ages.
Great to see new development with GaN based Class D amps, great to see Technics using DSP feed-forward designs to overcome minor limitations in impedance matching and Atmasphere’s work on reducing measurable distortion as well but OMG stop with the "Class D was awful until just now" threads as it ignores about 30 years of steady research and innovation.
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Can someone direct me to a good source to get a better understanding of the differences in Class A, A/B, & D amplifiers? I thank you in advance. Here you go, @allenf1963 https://en.wikipedia.org/wiki/Power_amplifier_classes |
@jwl244, Good to know. Barely scratching the surface of end-game potential, possibly. I won’t name the company, yet the owner of a different Co started wondering why they were getting more returns than ever anticipated on a solid sounding product. After some in-depth internal investigation ,something very telling surfaced for this Co. They instituted a (3x) much longer pre sale/shipping burn-in process to these particular class-D products and components. The customer returns dropped radically after this process was introduced. Then they tell the customer to give it another 100-200hrs for the final 5%. Not all, but some higher-end gear benefits from longer burn in cycles, finally reaching a set point, optimum specs, bias, and maybe the type of sound we all look for. Its definitely worth giving a try in the future, fwiw. Good luck. |
Going along with that, there is something about some Class D that requires DAYS to warm up. Even after being used and on for months my ICEPower monoblocks sound like garbage after being left off for a weekend. I have not run a binary search pattern to correlate time off vs. sound quality, but there have been about half a dozen other encounters with other audiophiles who have had this phenomenon. |
@decooney yes I've heard similar reports. I believe PS Audio burns in certain products before shipping as well. To be honest I'm not a huge proponent of burning in although your example would give credence to it. Not trying to get into a burn in or not thread.. I am curious in your opinion and others in this forum... Is one possible reason we lean away from class D because of its distortion profile or lack thereof? My understanding with the best class D and purifi products distortion is really low. Maybe I'm wrong. On the end of the spectrum class A and AB products introduction more distortion but in a "good way" and this creates that "tube" sound so many audiophiles gravitate to. I'm not saying there's no class a or ab products without low distortion. I'm saying the distortion introduced by those products might be more pleasing to our ears. This is the departure away from measurements and numbers and just what we like to hear. Maybe there's more of the 2nd order harmonics if you subscribe to that. Class D might be too clean after all making those products sound clinical and unexciting. |
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