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It was $10,000 four years ago:http://www.tmworld.com/article/317063-Prism_Sound_slashes_price_of_audio_analyzer.php
Makes SpectraPlus-DT look like a genuine bargain.
Mike, the FFT looks pretty good, the higher harmonics should be attenuated by the output filter so they will look increasingly better as the frequency goes up.
It's certainly hard to find fault with how this amp measures.Thanks for the new data, this is the first FFT I have seen of Brunos's new baby.Scotty
Here is a link to a Harmonic overtone calculator. http://www.sengpielaudio.com/calculator-harmonics.htmAs you can see from the calculator about the time you reach 5Khz to 6kHz the higher harmonics above the 3rd overtone fall at or above 20kHz. The output filter will quickly become a factor in your measurements as you look at the THD the amplifier might have at frequencies above 5Khz. Of course the bottom line is, the amplifier sounds good in addition to doing well on the test bench.Scotty
For higher fundamentals (eg 6 khz) the output filter won't have an effect until the frequency of the harmonic exceeds the corner frequency of the filter, or. 20 khz, which for 6 khz will be 4th harmonic (24 khz) upwards
Thanks for posting this! Those are very good measurements. Is the noise just over -115 dB part of the noise floor of the measuring device, or is that the noise floor of the amp?
Correctamundo, Mikes 1kHz FFT will not show the effects of the filter. The filters effect however can be seen on the THD measurements presented in the Ncore data sheets. From the the online calculator the 3rd harmonic overtone falls at 24kHz.
From the THD graph in the Ncore's datasheet, the output filter's effect on the amplifiers high frequency response can partially explain the reduction of THD seen in the graph as the frequency increases.Scotty
Hi guys,on this link there is a small signal frequency response for all loads (8, 4, and 2 oHms), but I`m curious what the large signal response would tell for the same loads, specifically, what would be the electrical power into 8, 4,and 2 oHms for 20Hz, 1kHz and 20kHz?http://www.hypex.nl/docs/nc1200%20folder%20web.pdfThe reason I`m asking is I have noticed non-linear behavior at small and large listening levels with some class-D amps. Some of them sound detailed at low listening levels, but much less at higher ones.I hope I can get a straight answer.Thanks!
That`s THD versus frequency and it tells nothing about the frequency linearity into various loads at full power.I would like to see the same frequency graph as in in 9.1, but measured at full power.
Got it. Sorry, can't find an equivalent with just FR measured...might want to email Bruno directly...Anand.
Maybe, if I get some time. I already owe a friend some measurements that I haven't gotten done yet. So you want to see THD vs Freq at 200W into 8R? By definition that is the clipping point, so it would be more relevant at something less than full power, especially, IMO, as 99.999% of all listening is done at low to medium power, at least in my world.
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