SP10 vs GL75 Rumble and wow and flutter

Hahah I was reading a review of the GL75 from Hifi News 1969 and the quoted figure for rumble on the GL75 is -60db but this is not the only source for this specification.

I then thought mischieviously I would compare this against the magnificent SP10 and Vinyl Engine gave the technics specification for the rumble on SP10 Mk2 at -50db!

I will look into wow and flutter....

That can't be right! If it is that is amazing. 

I see the manufacturers' quoted specs are

Technics 0.03%
Lenco GL75 0.6%

Sounds more like it.

Here I think www.lencoheaven.net/forum/index.php?topic=2138.0

As someone points out the App is not that accurate. Although could be he has fettled it to the point where he has improved on the manufacturer's quoted spec. 

I did mention unweighted for the SP10 Yes but even weighted its not much better than the Lenco!

Hahaha, mate, if you cant hear the significance of 10db....I envy you 🤣🤣

🤣🤣

These figures were from a standard GL75. Imagine what folk are getting in different plinths with different Isolation? I have read of even better figures for rumble.

Well done Macca, you got to the right article. Dr Feickert speed calculator is used by some of the industries best for analysing wow and flutter. In fact I have the app and test record ready to do my own set up.

test record will need to be absolutely flat with the hole dead centre otherwise you've got bob hope of getting an accurate figure.

Still, it is impressive that such an old design can manage such good performance.

I still remember with awe Barrington's massively modified Planar 3, where he'd polished the bearing shaft to such precision that you could not tell whether the platter was spinning or not unless you got your eyes to within a couple of inches of it. You could hear the difference too.

LOL I'm with James on this ( as a GL75 owner ) 

I know James is well aware of my opinion of the Lenco, in that its a great bit of kit for fettling and capable of a very respectabe level of performance, as Firebottles Lenco will demonstrate.

BUT

It always makes me chuckle how the "everything matters" mantra goes right out of the window when a favourable (to the owner or enthusiast) stat pops up somewhere and then it's the purported "inaudibility" that is the benchmark.

Well, if that's all that matters, you should be able to buy almost ANY turntable or DAC and it make no difference whatsoever. But we know that isnt the case.

Truth is, it WILL affect something somewhere, and it will have an effect that you do hear, which is why they bothered eradicating as much rumble as possible. I also don't buy the bragging rights argument either.

There are better TT's for Rumble, Wow and Flutter than the SP10 BTW, so don't misunderstand this post.

The Feickert is utterly useless for measuring wow and flutter. You have no access to the internal maths and the filtering is unknown, it's a Sh#t show.

You either need an optical encoder disk, or a standardised test record, not the hifi news or analogue productions ones, a real ISO test disk, and then perform a frequency demodulation.

Rega use an optical encoder disk, glass platter, litho engraved, for setting up their p10s, this is currently the limit of testing, a 1200 mark per rev disk giving an potential 0.15 degree raw accuracy that can be massively improved by performing a FIR on the output.

Sticking a phone on the platter doesnt come close.

Probably worth mentioning the lp12 rumble is high -70db A weighted. Mag levving the bearing gave another -3db improvement when we did Ynwoans deck, which was clearly audible and easily measurable.