GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Analog Playback
In the Thread: Turntable speed analysis.

Post Subject: Romy's SX8000 and test LP'sPosted by N-set on: 6/11/2012

N-set wrote:
AFAIR, what was missing for comparison are "portraits" of serious belt TT's. Anyone want to recorda test signal with his big belt TT and put it up in the thread for analysis (beware: it can do more harm to your ego than a timeline)?

I haven't been to the PinkFish thread for quite a while until yesterday. I see that Romy has kindly provided test signal from his SX8000.A big surprise! Why does the speed stability look so poor? I thought it would be rock-stable and we'd all take our small TT toys and go home.Well, it seems not. In the demodulated spectrum there is a whole comb of components. The group around 8Hz is probably cart/arm resonance.The polar plot has some clearly visible low freq. speed modulation (waviness) of unknown source (belt??) as well as thewhole figure is a bit elliptic, suggesting eccentricity somewhere, maybe both things are due to the test LP.As Paul R suggested in the thread, it'd be nice to repeat the test with some better known (i.e. already analyzed several times on different machines to see what is the LP's input) test LP.It seems that the best studied one in the thread is the Ultimate Analog (I also have Clearaudio and some of my tracks were analyzed with it,being expensive, super thick etc etc, it's still eccentric and even wrapped), although it's far from perfection.
Cheers, N-set

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