Idlers vs Direct Drive vs Belt Drive

[spiritofmusic]

Can I throw a curve ball into this argument?
Let us assume belt drive/dd/idler drive/direct rim drive could all be executed in cost no object designs to approximate perfect speed control etc. And rumble etc was made vanishingly low with again supremely executed idler drive and direct rim drive. So the lp spins consistently as good as we could want, and doesn't feedback to the stylus. Would we expect a different CHARACTER of sound with the platter being PULLED at 33.33rpm by a belt versus being DRIVEN at 33.33rpm by dd magnet/idler mechanism wheel/direct rim drive wheel?

 

[ddk]

David and Halcro both wrote that they have done this. I almost did too until I saw the "headphones" in the chain. Have David and Halcro really compared their turntables using headphones? I suspect Frantz's point is to take the airborne vibrations caused by the speakers out of the picture.

I ignored the headphone part. I haven't come across any headphone system that wasn't colored and completely deficient in bass unless artificially boosted. There's no comparison between headphones and even a decent, properly setup mid-fi system. Its absurd to think of such a limited frequency range transducer as the Reference when bass quality is the biggest difference between the three types.

No visiting audiophiles can tell (blind) which turntable is playing and neither can I really except on demanding material like full orchestral credenzas, solo piano, violin and guitar.
There are easily greater differences between cartridges than there are between these two fine decks..
I suspect the sound of these two decks might be more different than similar....?

I have become a skeptic but not a flat-earther ... I have gone through some good TTs in my audiophile life. It seems to me that the differences between the best TT is smaller than what we tend to make of them. Arms? Cartridges? Phono Stages? Vast differences.
You take some very good TT like say the SME 30, my SP10 MK3 or the Grand Prix Monaco with the same arm and cartridge , feeding the same Phono stage through the exact same system and you really think they will sound vastly different? I honestly suspect that when we look at the TTs already we start setting our minds to a certain "sound".

Gentlemen, Reference level tts this different have very distinct qualities and sound very different with exactly the same arm/cartridge, if what you say is really true then I would take a strong look at the system and setup, something is wrong.

david

 

[ddk]

I would say that all of our turntables are the same Keith. I have never once had to use the pitch knobs on the AF1

The pitch buttons are there as a convenient way feature to quickly counter balance a slow or fast recording. I like pitch control for other things too, a minor boost in speed will bring a little excitement to some duller recordings!

david

 

[ddk]

No in my opinion, if everything else were identical then the sound would be identical, again in my opinion well engineered turntables sound extremely similar, you can change the sound of course with your choice of cartridge and phono stage.
Keith.

How can that be when even the choice of oil for the bearing can make a substantial difference to the sound? I would look at that well engineered comment, only crap sound similar.

david

 

[spiritofmusic]

If one was sitting in a car, would the journey be different being pulled to yr destination at a constant 33.33mph, or pushed. Or is this a metaphysical question, the physics/mechanics being the same, but the experience different?

 

[rockitman]

I would say that all of our turntables are the same Keith. I have never once had to use the pitch knobs on the AF1

Pitch control has nothing to do with setting up the AF1. It is for adjustment if desired for a certain pressing the listener may want to tweak for whatever reason. So in affect, there is no speed adjustment for AF1 setup...only adjusting the belt tension. The micro-processor, ect sets the correct speed.

 

[Steve Williams]

Pitch control has nothing to do with setting up the AF1. It is for adjustment if desired for a certain pressing the listener may want to tweak for whatever reason. So in affect, there is no speed adjustment for AF1 setup...only adjusting the belt tension. The micro-processor, ect sets the correct speed.

I guess that was my point

 

[Mosin]

Is there provision to adjust speed?
As far as I am aware all belts stretch and contract, doesn't matter what they are made from, and it is that cumulative error .
Mosin is the Saskia belt drive, I seem to remember you experimenting with idlers ?
Keith

It uses an idler that has a very small contact area, so that any tracking error made by the wheel is extremely negligible to the point of the least possible. It has no pulleys and no shaft through the idler wheel, so run-out errors and any noise caused by mechanical friction is at the lowest level possible. It allows for pitch adjustment, and on-the-fly speed changes.

 

[rockitman]

You do realise that pitch control means either slowing or increasing the speed of the turntable, how do you initially set the correct speed ?
Keith.

you don't. The microprocessor does. Yeah, I know what pitch control is. Never touched it on the AF1.

 

[Halcro]

Gentlemen, Reference level tts this different have very distinct qualities and sound very different with exactly the same arm/cartridge, if what you say is really true then I would take a strong look at the system and setup, something is wrong.

Well...my experiences match those of Harry Weisfeld

I have an HR-X and a Direct drive next to each other with the same arm and cartridge. They sound very, very close with the speed stability of the DD giving it a hairs more breadth, depth and quietness. Small differences but that is what the high end is all about.

And suggesting that if we don't hear what you do David.....then there must be something wrong with our systems or set-ups, sounds a little condescending even if you didn't mean to..

 

[XV-1]

Gentlemen, Reference level tts this different have very distinct qualities and sound very different with exactly the same arm/cartridge, if what you say is really true then I would take a strong look at the system and setup, something is wrong.

david

100% agree, especially with a full range system.

 

[Mosin]

I have a question.

Several turntables have been mentioned in this thread that make corrections. Does anyone know how often they make corrections, and by how much they make them? Knowing these things will go a long way towards understanding how well engineered they are when it comes down to the inherent inertia qualities of their designs.

 

[microstrip]

This may help..No servo is used to control speed. The link provides full size.
(...)

Thanks Christian. It is now clear how the system works - it uses a servo until it reaches correct speed. From that moment on it is just a conventional fixed frequency synchronous motor driven by a by-phase optimum amplitude power signal. Any time you stop or disturb the platter significantly it just restarts the sequence again.

 

[ddk]

And suggesting that if we don't hear what you do David.....then there must be something wrong with our systems or set-ups, sounds a little condescending even if you didn't mean to..

Sorry if it came across that way I wasn't condescending, I was serious. I'd personally wonder why if nobody could distinguish between two such different tables in my system. The tables used in the OP aren't expensive or have any pretentions of grandeur but even at that level the differences among them are clearly audible.
david

 

[Mosin]

Sorry if it came across that way I wasn't condescending, I was serious. I'd personally wonder why if nobody could distinguish between two such different tables in my system. The tables used in the OP aren't expensive or have any pretentions of grandeur but even at that level the differences among them are clearly audible.
david

Steinway has an artist's showroom, so that pianists can hear their finest offerings. The pianos may look identical, may be built by the same guys, tuned by the same guy, etc. Still, each has its own characteristics that are noticeable by those who make them and by those who play them professionally. That not to say that even an ardent concert goer would ever notice the difference. He might, but he might not. I don't think an inability to hear the difference determines his appreciation of the concert, though.

Personally, I find the difference between turntables to be as varied as the differences between cartridges.

 

[Halcro]

I'd personally wonder why if nobody could distinguish between two such different tables in my system.

Then perhaps you should be manufacturing turntables instead of Harry Weisfeld?

 

[Halcro]

This Thread is developing the same way all similar Threads have on all the other Forums for years.
There is always a group of analogue aficionados who claim to hear "great" differences between turntables and because of the total subjectivity of their claims....there is never a resolution.
I however claim that the major differences between turntables (apart from platter mat/surface) resides with the speed consistency and accuracy they are able to maintain.
The first group never wish to involve themselves in the 'dirtiness' of scientific testing to disprove the possibility that maybe the differences they are hearing are caused by gross speed anomalies in their turntables of choice and the resulting conclusions that perhaps they are enamoured by 'distortions'?
So unless David can provide the Feikert Platter Speed App print-outs for all his turntables to establish a 'baseline' and remove doubt.....this discussion for me is at an end.

 

[Mosin]

Then perhaps you should be manufacturing turntables instead of Harry Weisfeld?

Let me get this straight...

Are you talking about that the differences you hear between a VPI belt drive and a VPI direct drive, or are you talking in general terms?

If the latter, which is the page David is on, surely you can hear a distinct difference between a Micro Seiki RX-1500, a Garrard 401, and a Technics SP-1000 mk3. If the former, I submit that the differences may be less apparent because they may be tuned to a "house" sound. Whatever the case, I am sure that David never intended to offend anyone.

 

[ddk]

Let me get this straight...

Are you talking about that the differences you hear between a VPI belt drive and a VPI direct drive, or are you talking in general terms?

If the latter, which is the page David is on, surely you can hear a distinct difference between a Micro Seiki RX-1500, a Garrard 401, and a Technics SP-1000 mk3. If the former, I submit that the differences may be less apparent because they may be tuned to a "house" sound. Whatever the case, I am sure that David never intended to offend anyone.

+1!
Thank you Win, right on both counts.
david

 

[Mosin]

The GPA Monaco whitepaper indicates: "The drive system uses a Digital Signal Processing (DSP) controller coupled to an optically encoded feed back loop to monitor and control the motor. It features an encoder disc with over 4,700 individual lines. The DSP system makes individual speed measurements and speed adjustments (if required) over 4,000 times a second. The system makes extremely sensitive adjustments to the energy being fed to the motor in a way that will maintain unparalleled speed accuracy. The system operates on a nominal 5 volts DC." The encoder disc is attached to platter and it is the speed of the platter that is controlled.

That still doesn't tell us the amount of adjustment per step. What I am trying to determine is how invasive the adjustments might be.

For example, a Saskia turntable makes 1/1000Hz adjustments. That's a change down there with normal wall current fluctuations. Then, it may go hours without needing to make any at all. What I am trying to point out is that feedback can be a good thing, but if the turntable's inertia and overall drive scheme isn't pretty much right at the outset, it's all moot.