Esoteric Grandioso T1 turntable arrives; G1X Master Clock coming.

[Mike Lavigne]

It does appear to be some form of cogging, but the rate of oscillations doesn't look right. If it were the rotor/platter interface cogging, it would occur at every "tooth" which would be much more often than what I see to be ~20° per oscillation. If it were the motor cogging, it would be even finer and IME, not visible to the naked eye (the plots I posted previously show no visible signs of oscillations, they are only detectable using an optical encoder). What ever it is appears to diminish as the speed increases, but I wonder how low it is at operating speed?

we do have some information, both listening and measuring.

i will again point out that Fremer's T1 review is clear about the significance of the speed steadiness, and it's significance on the music, and
he did measure it with the Shaknspin. "Though the Shaknspin (shaknspin. wordpress.com) isn’t a “lab-grade” test device, it’s 9 degrees of freedom sensor produces useful data. Better tables always produce better measured performance. Putting the OMA direct drive’s results side by side with the Grandioso’s makes clear that the MagneDrive system’s speed consistency (at least measured with this device) is comparable to the direct drive’s."

and i have 2 turntables sitting here next to my T1 which have excellent speed performance, the CS Port LFT1 and the NVS. as good as those are, the T1 is better.

 

[Phoenix Engineering]

we do have some information, both listening and measuring.

i will again point out that Fremer's T1 review is clear about the significance of the speed steadiness, and it's significance on the music, and
he did measure it with the Shaknspin. "Though the Shaknspin (shaknspin. wordpress.com) isn’t a “lab-grade” test device, it’s 9 degrees of freedom sensor produces useful data. Better tables always produce better measured performance. Putting the OMA direct drive’s results side by side with the Grandioso’s makes clear that the MagneDrive system’s speed consistency (at least measured with this device) is comparable to the direct drive’s."

and i have 2 turntables sitting here next to my T1 which have excellent speed performance, the CS Port LFT1 and the NVS. as good as those are, the T1 is better.

You've posted that before, but it doesn't show a measurement; Fremer used to show the actual data results in the form of a graph with actual readings. What exactly does "comparable" mean quantitatively? It's really more of an opinion.

Even the graphs he used to post can be suspect as they usually filter out the low frequency component to eliminate WOW caused by eccentric records, but that also removes important information about the drive. It would be interesting to identify the frequency of oscillations then focus specifically on that band.

 

[Mike Lavigne]

You've posted that before, but it doesn't show a measurement; Fremer used to show the actual data results in the form of a graph with actual readings. What exactly does "comparable" mean quantitatively? It's really more of an opinion.

Even the graphs he used to post can be suspect as they usually filter out the low frequency component to eliminate WOW caused by eccentric records, but that also removes important information about the drive. It would be interesting to identify the frequency of oscillations then focus specifically on that band.

please let's see that for other tt's in the 'uber' category too. i could name names.

we know that's not going to happen.

i have no interest in that anyway, but some do. they ought to buy a T1 and measure it. Fremer is careful to point out that he finds the best sounding turntables also measure the best with his Shaknspin, but he does not look for good measuring turntables and then listen, it's the other way around. so far, there is a correlation. he did publish the Shaknspin data for the OMA K3.

 

[Mike Lavigne]

This is an interesting comment from Michael Fremer. A friend and I compared the speed performance of my SME model 30 to his Technics SP 10 Mk III. This was in my system both tables sitting on the same platform. We checked both their speeds and made videos using the Sutherland timeline strobe device. The direct drive turntable appeared to measure better than the SME, though he and I both agreed that the SME sounded much better. This was with the same tonearm same cable and same cartridge.

Of course it depends what “better“ means, but in this case, the better (sounding) turntable did not produce better measured (sound) performance. That technics turntable has some of the best speed stability of any turntable made. Do people consider the Technics one of the best sounding turntables?

Perhaps I do not fully understand what Fremer is trying to say here.

he relates his personal experience since he started using the Shaknspin device. read his K3 review and T1 review and others and you will get a feel for what he is saying.

it's nothing that is a broad brush, only that he sees a correlation.

there are plenty of ways to measure things. but he likes this device as it seems to also track with what he hears.

the Timeline is a once a rotation measurement, so not really addressing steadiness or wow and flutter at all, just samples speed.

 

[Mike Lavigne]

regarding the cogging subject,

"the system can be driven with rectangular pulses, but to achieve better pole to pole transitions, the driver provides pure sine wave current to the motor coils."

 

[Ron Resnick]

Of course it depends what “better“ means, but in this case, the better (sounding) turntable did not produce better measured (sound) performance. That technics turntable has some of the best speed stability of any turntable made.

This sure can be a confounding hobby!

 

[morricab]

@Phoenix Engineering, here is a video showing a very interesting effect on the platter during start up. Go to the 8:00 mark. Is this the kind of behavior that the clock is meant to address? The effect is very pronounced during start up and hard to see at faster speeds but it still must be occurring unless corrective measures are taken. At what point does this become less audible?

Yes, looks like gears and not continuous movement.

 

[Mike Lavigne]

This sure can be a confounding hobby!

Ron, did you see my comment in my post above where i mention that the Timeline device that Peter used only measured speed once a rotation. it did not measure steadiness, wow, or flutter.

since it did not really help Peter to determine better performance that device had limited value, it could tell you gross speed differences, but that's about it. so not really too confounding.

 

[Solypsa]

In general people seem to feel this is a great sounding table. So IMHO this is a fun opportunity to ask 'why' and not 'why not' iow what is working here?

Still if @Phoenix Engineering wants to cobble up an amazon clock with ps and cable I don't see why it shouldn't be tried

 

[Mike Lavigne]

In general people seem to feel this is a great sounding table. So IMHO this is a fun opportunity to ask 'why' and not 'why not' iow what is working here?

have at it.

Still if @Phoenix Engineering wants to cobble up an amazon clock with ps and cable I don't see why it shouldn't be tried

all he needs is a T1.....and a G1X clock to compare.

 

[Solypsa]

Haven't a clue just happy it works

 

[Phoenix Engineering]

regarding the cogging subject,

"the system can be driven with rectangular pulses, but to achieve better pole to pole transitions, the driver provides pure sine wave current to the motor coils."

Cogging will not be affected by the drive signal; in fact, PWM is the preferred way to drive these motors as it allows smaller changes and slower speed where sinewave drive does not. A good analogy is model trains; if you use DC voltage to control the speed, the train stops moving at a much higher speed than most enthusiasts would prefer because the motor will lack sufficient torque to overcome losses. Using PWM, you can control the speed all the way down to stopped and small changes will take effect more accurately. The same applies to TT motors; with PWM you will be able to control small changes much more accurately than with sinewave drive and it works smoother at slower speeds.

Cogging is caused by changes in magnetic reluctance within the motor and between the motor/platter interface.

 

[PeterA]

Ron, did you see my comment in my post above where i mention that the Timeline device that Peter used only measured speed once a rotation. it did not measure steadiness, wow, or flutter.

since it did not really help Peter to determine better performance that device had limited value, it could tell you gross speed differences, but that's about it. so not really too confounding.

Actually Mike, it did help me determine better performance: speed performance. I really like the device because it is very accurate for speed, quick and easy to use. What is also showed is that there is more to great sound than just speed performance. We found that out with the Japanese DD tables from the 1980s. The SME simply sounded better to us despite it having less accurate and stable speed.

The Timeline is good because you can measure the platter speed while playing a record. This shows the effect of stylus drag. One revolution at 33.333 rpm is 1.8 seconds. The timeline blinks six times in that interval. There are six (6) dashes spread around the perimeter of the room at equal intervals. If you look at one dash on the wall, if there is any wow in flutter, the length of the dash fluctuates. Very steady speed shows a dash which is the same dimension (length) and remains precisely located (does not move) and very consistent across the room. Very few turntables can demonstrate this. It shows speed accuracy by indicating whether or not the dash moves forward or backward from a set location at a given distance away from the turntable, and it shows consistency by the size of the dash.

Putting this device on various turntables at dealerships or at an audio show can be very humbling. I went into a dealership did not allow me to use the device at all on any of their turntables.

People can certainly dismiss it. Some turntables which indicate speed showed 33.3. Other show 33.33. In some show 33.333.

The Timeline output of my table is now like that of the DD Technics SP10 III, very steady and stable, but they sound very different as would be expected.

 

[Solypsa]

Cogging will not be affected by the drive signal; in fact, PWM is the preferred way to drive these motors as it allows smaller changes and slower speed where sinewave drive does not. A good analogy is model trains; if you use DC voltage to control the speed, the train stops moving at a much higher speed than most enthusiasts would prefer because the motor will lack sufficient torque to overcome losses. Using PWM, you can control the speed all the way down to stopped and small changes will take effect more accurately. The same applies to TT motors; with PWM you will be able to control small changes much more accurately than with sinewave drive and it works smoother at slower speeds.

Cogging is caused by changes in magnetic reluctance within the motor and between the motor/platter interface.

Really appreciate your participation here - so many nuggets to glean

 

[Solypsa]

Some turntables which indicate speed showed 33.3. Other show 33.33. In some show 33.333.

Indicated speed only matters if you know the accuracy of the indicator

 

[Ron Resnick]

Ron, did you see my comment in my post above where i mention that the Timeline device that Peter used only measured speed once a rotation. it did not measure steadiness, wow, or flutter.

since it did not really help Peter to determine better performance that device had limited value, it could tell you gross speed differences, but that's about it. so not really too confounding.

Fair enough. I understood Peter to be citing only speed stability and not steadiness, wow or flutter.

I was commenting only narrowly that that one particular objective measurement -- speed stability -- is not enough, I guess, to predict subjective sound superiority.

I think Peter likes posting about speed stability because that is the one parameter he is able to measure on the AS-2000.

 

[PeterA]

Fair enough. I understood Peter to be citing only speed stability and not steadiness, wow or flutter.

I was commenting only narrowly that that one particular objective measurement -- speed stability -- is not enough, I guess, to predict subjective sound superiority.

I think Peter likes posting about speed stability because that is the one parameter he is able to measure on the AS-2000.

Ron, what is the difference between speed stability and steadiness/wow and flutter? I think of accuracy (33.333 rpm) and stability (ability to not fluctuate from xx.xxx). I have been discussing both in these last few posts.

I have always been fascinated by turntable speed, both accuracy and stability. There are many ways to measure both. I have been able to measure both using a standard strobe disk going back to college days, and I have measured all four turntables I have owned since that first Denon DD. The Micro Seiki was measured with a strobe, the RoadRunner, and the TimeLine, as was my current table.

 

[Mike Lavigne]

Ron, what is the difference between speed stability and steadiness/wow and flutter?

no difference. speed stability = steadiness. wow and flutter are mostly degrees of distortion from that state.

I think of accuracy (33.333 rpm) and stability (ability to not fluctuate from xx.xxx).

??? huh?

stability is a different concept than speed accuracy. speed can be stable at any speed. and accuracy is about units of measure. that idea then tips over into servo's and feedback and the effect of speeding up and slowing down. types of drives, etc, etc.

I have been discussing both in these last few posts.

I have always been fascinated by turntable speed, both accuracy and stability. There are many ways to measure both. I have been able to measure both using a standard strobe disk going back to college days, and I have measured all four turntables I have owned since that first Denon DD. The Micro Seiki was measured with a strobe, the RoadRunner, and the TimeLine, as was my current table.

investigate Shaknspin.

the human ear is the final arbiter of correct speed, steadiness and musical flow.

 

[Mike Lavigne]

Mike, have you tested the speed of your table with a device to confirm the xx.xx display?

the T1 speed read out goes to xx.xx.

i've seen Fremer's measurements, but they are not mine to share. you already know i'm not measuring sh*t.

Can you tell us how adjusting the distance between the drive wheel and the platter affects the speed and the sound?

only played with it twice, it's like what Fremer writes.

there is a dial with 20 steps, 4 full turns (4 x 20 = 80 steps) moves the distance 1mm, which is the total distance of adjustment. farther out is more like belt drive, a bit more spacious and laid back, then closest is a bit more torque, focused and dynamic, more like direct drive. the middle seems more idler to me, especially past center. based on my experience with different drive types.

these are very nuanced differences. nothing that jumps out. but they are musically significant. they do not effect speed or steadiness.

with only a little playing around, i prefer 2/3rds toward closer. 52 of 80 steps. only used a few cuts to investigate. but i expect in the future to play around with it more. i could see using more varied types of music to see of this setting is best when i am in the mood to go there.

i love how it sounds.

i could see maybe adjusting it for different types of music, but unlikely i would do that. but it would be a reasonable thing to do. it's very easy and precise to adjust. as long as you keep track of where you are. if you do lose track it's not a big deal to re-boot back to zero and then do it again. there is a process.

 

[Mike Lavigne]

Thank you Mike. The coupling between the drive wheel and the platter is changing and that must affect speed somehow because the sound changes.

it's not changing in the normal sense, only the gap is changing. but the speed does not change according to Esoteric. just the amount of torque behind the drive. certainly the sustain of pianos and horns is the exact same at whatever setting. to me more significant than any number on a scale.

This is one of the really interesting features of the turntable. It makes me think of thread or belt tension which is really adjusting the coupling between the motor and the platter.

i agree there is a common idea to changing belt tension, but likely many more variables, more a matter of feel, since there is actual contact. just my opinion. i have my own thread drive sitting here i can do that with too. certainly the precision and repeatability i can adjust the T1 is much greater than messing with thread tension. but the same forces are at play for sure.

I’m sure those who understand what’s going on would have a better explanation. I look forward to reading Fremer’s review when I have access to it.

got my hard copy of Absolute Sound today with the review. we are last to get stuff here on the Left Coast.....so everyone should have theirs by now.

the review was on line on a review site last week but it's gone now.