Grand Prix Audio Monaco Turntable

Sure, if speed stability is in question then you should be able to hear one source run a bit behind,then eventually catch up again to achieve the .00008333% error after 6 mins. That should be something noticeable during the test but it didn't happen on mine. :)

I didn't get to add, ideally I'd like to have the turntable on the left side of the headphones and the cd player on the right side of the headphones but I don't have the right cables for such.

I would think that instability such as that caused by belt slippage would show up as momentary lagging on transients that would then not catch up. Instability caused by motor issues wouldn't show up at all in terms of noticieable echo, but would be much subtler involving tonal cleanliness especially in the high frequencies. This is what Michael Fremer was concerned might be happening with the Monaco.

If one has the time(because it is an extremely long article)the Peter Montcrieff article on his E-mag(IAR)has some thought provoking information,which gives creedence to the subject.Very long winded,but very good too!
Best.

when both speed accuracy and stability is achieved to a high degree the music attains a solidity and tonal integrity which must be heard to be appreciated. my Rockport System III Sirius direct drive motor......"yields speed accuracies on the order of 10 parts per million with absolutely zero torque ripple".

it also has a servo which totally corrects groove modulation on musical peaks. this aspect of speed stability cannot be stated too strongly. every belt driven tt and many direct drive tt's will be effected by groove modulation (kickback from the additional friction) and most listeners assume the effect of groove modulation is in the recording. it is only when you hear the recording played back without any groove modulation that it's affect is recognized. on musical peaks you might assume it's your amp or speakers are distorting.....but it's only the slight speed hesitation which causes the distortion and momentary loss of musical flow and cohesivness.

hearing a concert grand piano Lp played back at high volume on the Rockport is revelatory. lots of dynamics and overtones.....any non-linearities jump right out. then on anything else.....not the same.

Peter Montcrief's article summarizes the advantages nicely.

i have played CD's along with Lps on the Rockport....and the timing is perfect.....the problem becomes the space between cuts.....which do not always match.

there is more to tt performance than speed correctness; but music is mostly a matter of timing.....getting it right is much of the challenge.

Sirspeedy, Mike, thanks for sharing and commenting on that interesting article
by Peter Montcrieff...it is pretty longwinded, but very relevant and informative
(especially to me being new to this) and to be continued too! Didn't read
anything about the Sirius III technology in it as the title might have suggested.

In the end my takeaway is that all belt tt's have no hope in hell to ever achieving
timing right, which leaves us with direct drive. Which in turns leads us to the GPA
Monaco and Alvin's unique implementation on speed control. Would any of you
care to comment on the differences in say, the Technics SP10, Rockport Sirius III
and GPA Monaco on how they deal with this? Or point to some discussion
happening elsewhere on the web.

Many thanks!