2. amps-preamps
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Class D is just Dandy!

I thought it was time we had a pro- Class D thread. There's plenty of threads about comparisons, or detractors of Class D.

That's fine, you don't have to like Class D amps, and if you don't please go participate on one of those threads.

For those of us who are very happy and excited about having musical, capable amps that we can afford to keep on 24/7 and don't require large spaces to put them in, this thread is for you.

Please share your experiences with class D amps!
erik_squires
erik_squires OP
15,990 posts
 
At $17k a pair? No. No thank you.

I’ve heard current linear amps that were about that expensive and I wouldn’t switch to them either. To me the idea that we need super technology to finally fix the Class D problem just wont’ fly.

Blame my tin ears if you must, but this was solved a decade ago.

Best,

E
erik_squires OP
15,990 posts
 
Also, the meters on the Technics SE-R1 are super cool. Wish I could buy the casework alone.
guidocorona
4,298 posts
 

@noble100 

Tim, I love your quote from the upcoming issue of Acta Philosophica Refutata (Vol XXVIII, Feb 29th, 2017.... I have not yet received this issue *Grins!*


Jokes aside, it is my understanding that this conjecture -- it is not a theory in the scientific sense of the word -- asserts that switching frequencies of at least 1Mhz are expected to reduce harmonic distortion to 0.005% or better.


It happens that 0.003% has already been achieved for the entire audible frequency band: Mola Mola Kaluga which uses enhanced versions of NCore NC1200 and its matching power supply. ROwland M925 and M825 are also below 0.005% while using stock NC1200 modules.


But let us come down to Earth from the audiophrenic stratosphere above.... The reasonably priced $2500 Merrill Teranis, based on the lower cost NC500 NCore module, declares a THD of 0.005%, thus achieving the preported distortion goal, using a trickled-down version of NCore, with is mainstream switching frequency of about 450 Khz.


G.


erik_squires OP
15,990 posts
 
Hi @guidocorona

The general principles that a higher switching frequency with better transistors yields lower distortion and higher efficiency is not really in question.

I question the audibility of anything measurably better than the current state of the art from ICEPower, nCore or Pascal. I question the importance of 0.03% distortion vs. 0.003% vs. 0.00000001%.  Having a baking scale that measures in femto-grams does not help you bake a better cookie.

If there are audible benefits, I think the answer will be somewhere else. Such as linearity (lack of compression), noise shape or handling difficult to drive speakers (complex impedance curves), etc.

I won’t get excited at all right now over an amp with a high switching frequency, or lower distortion. Especially not at high end prices.

There may be audible differences between the major Class-D technologies, but harping on things I think were solved a decade ago I don’t think will help me find a "better" sounding amp. Maybe a "different" sounding amp though.

Best,

E


guidocorona
4,298 posts
 

Hi Erik, the inability of class D amps to handle difficult loads is one more urban legend....  Most non-trickle down modules that I know have damping factors of 1000 or better, and deliver 30A or better..... NCore NC1200 for one thing drive my difficult to handle Vienna DIe Muzik, with their wild impedance curve, without batting an eye... Even the little Merril Teranis could do it without a sweat, once we raised its gain to 029dB.


In olden days, I heard a ROwland M312 (ICEpower 1000ASP) totally trashing the authority and harmonic resolution of a big Boulder 2000 series monoblock pair driving Die Muzik... Not only my opinion either... there were about 15 people in the room.



Guido

   

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