@jeales Your statement about frequency response varies by load on class D amps is not necessarily true. I have now built 11 different Class D amplifiers. 3 of them are very good and 2 of them, I was able to modify or add
PFFB circuitry. It is similar to an impedance correction circuit. On my 2 amps that I've added this, frequency response does not vary with load.... I'm not sure how widely this is used, but it is definitely out there.
Class D amps that are superior to all or most?
Recently, I have heard about some Class D amps that may be close to the best there is regardless of class. Certainly, this technology has been in development for decades. The main issue has always been the switching power supply. In this regard, I have taken notice of AGD. They have created a whole new power supply that “switches” at a frequency 100 times the normal silicon based MOSFET. The designer uses a gallium nitride based PS. Interesting, it is enclosed in the KT88 glass envelope that sits on top of his amps. I am aware of two more pricey amps that seem to be also at the top- the Solution and the Merrill. There must be others that compete for the title. After my thread, “Is there a SS amp that can satisfy a SET guy?”, I am still on the quest.
Don’t want to spend $50K!
Don’t want to spend $50K!
- ...
- 297 posts total
timlub1,865 posts05-08-2021 10:31am I believe it is, as the best I’ve heard Belcanto M600 monoblocks (NC500) is through a very benign 6ohm 2 way stand mount, that used a Raven ribbon tweeter, which is basically a load that looks like a 6ohm resistor. On more expensive ML ESL’s and other good floor standers they didn’t sound as good through the upper mids and highs, a little artificial and cold. And as far as measurements go, class-D get exponentially worse distortion figures when differently loaded the higher the frequency is, look at any tested Stereophile distortion graphs done on class-D (new Mytek Brooklyn) rising distortions upward from 1.5khz https://www.stereophile.com/images/421Mytekfig06.jpg Compared to a linear amplifier, much better far lower, and starts to rise higher and gradual, not so savagely rising https://www.stereophile.com/images/1115BAHB2fig07.jpg Cheers George |
frequency response does not vary with load...Define load. Non inductive load resistor, speaker simulator or something like this Elac Debut B6 https://www.stereophile.com/images/416Elacfig1.jpg. or Klipsch Forte III https://www.stereophile.com/images/719KF3-fig1.jpg |
| Post removed |
carlsbad Coincidentally I just got MLs and my tinnitus is quite a bit louder than normal. I've wondered if it was the brighter highs. but it is probably just that I'm listening to it more. I don't listen very loud, in brighter speakers I listen quieter. I'd say you haven't really heard what those ESL's can achieve in the upper mids/highs, until they are driven with a good linear high bias class-A/B amp. Cheers George |
- 297 posts total