Class D amps seem poised to take over. Then what?
Everyone has an opinion - which is good - not everyone agrees with another persons opinion Difference is, these are measured facts, and not my opinion. And if one dismisses them then this is what they believe, https://i.dailymail.co.uk/i/pix/scaled/2013/12/18/article-0-1A2B262D00000578-818_636x382.jpg as every decent piece of audio gear is designed by the laws of electronic design |
Next you’ll say an OTL of Ralphs can drive those Wilsons to their best properly, because they too will stay stable into them and not oscillate.🤷♂️The sales manager of Wilson had our amps for many years. FWIW our OTLs are inherently stable and will not oscillate with any load or input signal condition. they are fets, and fets can’t do doubling of 8 to 4 to 2ohms (current) like complimentary bi-polars (bjt) can do like in the the Gryphon Antillion, bigger Krell, D’Agostino Boulder, etc etc etcThis one gave me a good chuckle- its so ridiculously false as to be funny! This statement ignores a simple fact about GaNFETs which is their ON resistance is one of the lowest values of any semiconductor. One reason I bought AGD is because I was convinced that they stood apart from all other Class D.It certainly helps when designing a switching amplifier to have also participated in related patents to switching transistors as Alberto has! But if you want to know why his amplifier sounds right, take a look at the distortion signature he shows on his website. If you look at the values you'll see that its not particularly low, but what is important (and IME arguably more important that *how much* distortion you have) is that the signature is what you want to see to prevent the amp sounding harsh. Here's the link https://agdproduction.com/audion/ scroll down and click on either of the THD images. You'll see that the 2nd and 3rd harmonics predominate. These harmonics are nearly inaudible to the human ear and because they are so prominent, they mask the higher orders (which otherwise are audible usually as harshness and brightness). This distortion signature looks very similar to that of our OTLs (although we show more 3rd and less 2nd due to our differential design). This type of distortion signature will cause **any** amplifier to sound smooth and organic. The lower the distortion the more detailed the amp will be without also being bright. I've said many times that the differences we hear in amplifiers has more to do with what distortion we can hear and what distortion that we can't. This is more important than output impedance because the ear has a tipping point where tonality generated by distortion gets more attention than actual frequency response. Class D amps can have a signature like this because the errors (non-linearities) in the encoding scheme and the dead time requirements (if handled correctly) tend to result in lower ordered harmonic production. (There is more to it than that of course...) In a nutshell this will cause them to sound like a state of the art tube amplifier that acts as a virtually perfect voltage source. If you are pragmatic as a designer you know that you can't make an amp with no distortion :) The savvy designer will thus see to it that the distortion that is present is innocuous and this is a good example of how that is done. |
georgehifi atmasphere Dream on sunshine, were talking about driving the Wilsons mentioned here. Trust you to try to skew it around to make out that your OTL amps could even come close to driving these, the hardest of Wilsons to drive (Always looking for the self promoting angle) |
