2008 RMAF – – – all things analog.

Grooves, You make an excellent and valid point. So, what do you personally think accounts for the qualitative difference in sound between the best direct-drives and idler-drive tables on the one hand and belt-drive tables on the other? We all or most of us seem to agree that such a difference exists, except maybe as regards the very best belt-drive tables (not necessarily the most expensive). Couldn't it be that we are hearing an additive effect of speed instability due to the turntable on top of speed instability due to eccentrically cut records (i.e., nearly all of them)? What might be happening is that the brain learns to accept the sound from a given LP, good or bad, as a baseline for comparison of turntable performance. Most of us use LPs with which we are very familiar in the turntable comparison process.

I'm not sure anyone has said speed perfection is the sole goal. Obviously, taking that approach would lead to problems elsewhere, most of which would mask any benefit of perfect speed.

CD = perfection? That's a whole different topic itself, but I get your intent.

We have this tiny diamond, at times wiggly back and forth and up and down at some pretty high frequencies. Assuming that the cartridge is good enough to not skip even in the slightest, that has to have some effect on something, IMO. Those of us who use the mylar belts have heard remarkable improvements with different versions of the mylar streamers and, most notably, with Paul's latest trick of etching away the metal to expose the textured side of the mylar. Something is going on.

CD = Perfection... except for jitter. Timing errors seem to be an achillies heel for both analog an digital.

Dear grooves: IMHO I don't think that that poit was missed, things are that we were argue on TT speed accuracy and speed stability and what could alter the platter speed stability.
This subject beguin with a comment that Doug posted about stylus drag and its influence on that platter speed stability and that's why we don't go in deep to any other source ( other that the TT it sef ) that affect about.

We all know that the analog source is probably the most imperfect " world " to music reproduction but at the same time I know too that the ones in this forum agree that the analog source is the most beautiful and enjoyable one for a home muic reproduction other than a live event or a Studer one with original master recordings.

As always things are that everything has its own trade-offs, take the TX-1000 that fix the eccentricity of the LP, well it is not a perfect machine from the point of view about its tonearm or about its DD motor or suspention: anyway is worth to hear it only because its eccentricity fix function.

Now, IMHO the digital source is almost perfect but like Teres point out it is not " perfect ", btw nothing is.

All that analog imperfection world makes that any one of us ( including a pro-reviewer like you ) that cares about music and about music reproduction have to take extremely care on the right set up and right choice of hardware ( synergy, the real one not for compensate errors in the audio chain. ) at each link in the whole audio chain.

Some of us are truly " perfeccionist " about ( that's why we discuss about the relationship between stylus drag and platter spped un-stabilities. ), my point of view is that pro-reviewers must be ( at least ) in the same way and for what I read through your reviews and other people reviews some are far from there.

My thoughts about pro-reviewers is that al these very special people have a great responsability: help for the analog high-end grow up faster and with real quality improvements in any step that the analog industry take it.

It is sad for me to say that certainly ( today ) that is not what is happening from my point of view ( I could name it many examples of that ). This is not the time or the thread to analyze in deep about, I hope that over the time all us have the opportunity to return on the subject because we need to improve, we need to be better, we need to " dream " again.

Regards and enjoy the music.
Raul.

I can point to one thing that no-one seems to be talking about here. If you have a servo system controlling the motor speed, then you will experience a phenomena known as 'hunting'. This is where the servo detects that the speed is off and compensates for it. Actually, in order to do that, it has to overcompensate. So now the speed is off in the other direction, so the process repeats.

If you look at the resulting speed stability, it looks a bit like a sine wave.

Now there are ways to reduce this effect, for example by cutting the motor/platter system out of the loop, so the 'speed stability' insofar as the servo is concerned is limited to the frequency stability of the servo's inner clocks. Some servos ignore the platter and simply focus on the motor shaft rpm. Whatever the approach (and I am grossly oversimplifying this whole thing), one thing that can be counted on is that if you have a servo, its likely that it is off speed while you are listening.

Technics did an admirable job with the SP10 in that it was the first and IME the *only* DD wherein the servo issues had been developed well enough that the table actually brought home the bacon. Most of the servos I see for BD tables are inadequate, but I've not seen everything out there by any means.

Synchronous motors and eddy current motors are locked to the line frequency which is regulated by the power utility company. Power utility speed stability is very exact; their hunting cycle takes a few hours under normal circumstances. That allows for the possibility for such motors to be the most speed stable. This is why, I think, that rim drive has resurfaced after decades of being the black sheep (due to noise and lack of precision). This is also, I think, why a BD table with such motors can also exhibit the same stability.

This is a far more pronounced issue than stylus drag, however I should point out that a weak servo or weaker motor will indeed have stylus drag issues- in servicing hundreds of tables over the years, I have seen the effect be quite measurable, although not on any table with a robust drive.

One thing you will see that the SP10 has in common with other 'speed stable'/'stylus drag resistant' machines is that it also has a robust drive.

So, IMO, a machine that will truly speed stable will have a heavy platter, a robust motor and either a **very well** thought out and executed servo, or none at all. What will not be a variable is the actual drive itself- belt, DD or rim, they are all going to work if properly executed.