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Welcome Licorice Pizza (LP) lovers! Setup guides and Vinyl FAQ.

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Spikes above about 18kHz?

Posted by mr.bear on April 19, 2017 at 12:48:41:
The spectral plots are following RIAA equalization, I assume?

MM or MC cartridge? I would have assumed its unlikely to get that much ultrasonic garbage from an MM- just considering the filter formed by the cart coils and the input capacitance)

The left screen shows a sizeable spike around 18kHz and a few lesser ones above 20 kHz; these seem totally absent on the right screen. Whatever that is, it ain't music.

Too much ultrasonic energy could have an effect in some amps, causing distortion in later stages assuming that high frequency stuff gets passed through the RIAA stage without much attenuation (I'm thinking about slew-rate limitations, in the power amp).

That HF energy crept in seemingly on the vinyl itself - since the right plot looks so "well-behaved." Or am I misunderstanding something bout the nature of these plots?