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In Reply to: RE: Are you aware the output filter in most better class d amps is part of the feedback loop and thus their posted by pictureguy on November 09, 2015 at 14:48:04
nt
try it! you know you want to!
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Please, Kur, go find a review with Measured Data.
Frequency Response FALLS more quickly with lower impedance loads on amps with the output Zobel.
This falling response ALSO induces Phase Problems which MAY be audible.
Too much is never enough
Where? Oh, you mean out past 30KHz?
try it! you know you want to!
To also cherry pick the data, the ASP 500 module, the 'big guy' in the series was down 1/2db or so at 20khz. This produces notable phase shift in the audio band. And, if it matters, really odd looking 10khz square wave response.
I'm not going to try to find the measured data. You can find it if you are really interested.
Too much is never enough
hard to prove it's audibility at high frequencies where moving your head a few centimeters produced much more phase shift.
"The hardest thing of all is to find a black cat in a dark room, especially if there is no cat" - Confucius
I stated that the ncore uses post filter feedback and thus the frequency response was load independent. The graph I posted shows that....Half dB down at 20KHz might bother the dog but I can't hear it and I doubt anyone reading this can either...
try it! you know you want to!
If you bothered to READ my post, I stipulated the B&O ASP module.
Sure, other 'd' designs, notably the ncore have skipped the output filtration.
And it's not the amount 'down' that counts, but rather the phase shift this induces. I believe this was what caused problems with my panels. There was something just not right about the highs.
Too much is never enough
If you had bothered to read my post, you might have noticed it was a reply concerning class d amps in general that contain the output filter in the feedback loop. Ncore doesn't "skip" output filtration, it's in the feedback loop, same as with Icepower, by the way....though they take feedback both pre and post output filter.
try it! you know you want to!
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