Turntable upgrade recommendations: SME vs AMG vs Technics vs other

@mijostyn 

Thanks for your input on air bearings. I agree that air in all directions is important - how not when I can hear the sleeve bearings of my 2W precision motor? Even through a belt! 

Didn't know that air in all directions was so rare. That's quite a surprise to me. But then I don't shop at the 100k mark - I'd rather build it.

MODS - attention please.

When trying to post, I am sometimes asked to prove that I'm not a robot. But the last inch of screen is obscured, and the page will not scroll. Could you pass this bug along to the systems people, please?

@rauliruegas

"Any body in movement develops internal vibrations/resonances "

Almost true. But those resonances must be excited by vibration. Where does that energy come from? Not the air bearing - you are thinking of a conventional bearing, perhaps. The only other significant source of energy is the electronic jitter from a motor, and the worst are DD, then idler drive. And the more powerful the motor, the more energy to spill over into the platter and excite those resonances.

@rauliruegas 

"SME has nothing to envy against those air bearing TT designs."

Not even a completely silent bearing?

@alexberger

I had a similar experience with a NA Spacedeck compared to an upscale NA, the Mentor.

Happened gain when upgraded the Mentor to full NA Dais specifications.

Happened again with the modern power supply.

Happened again with air bearing.

May not be the drive system.

@mijostyn 

True, a resonance can develop. But this is easily controlled with a massive platter, a well damped air supply, and tuned air pressure. There is no reason to think that magnetic suspension is quieter, but there is good reason to be suspicious of stray magnetic fields near a MC cartridge, especially if these are sufficient to levitate a high mass platter. 

A high mass platter is important to smooth the electronic jitter from cogging at the poles of an AC motor or the constant corrections of a DC motor controller.

IMO.  YMMV

@mijostyn

"Raul mentions the heavier the platter the higher the resonance frequency and there is no practical way to dampen an air thrust bearing. All you can do is adjust the frequency it resonates at"

Not so. A properly designed platter does not resonate. Walker uses lead loaded epoxy, so I understand. Nottingham uses sculpted cast iron topped with carbon composite. TechDAS uses 5 layers of metal, according to their literature. I use sculpted cast iron topped with an inch of graphite, 45 kg, and although each section rings (near 500Hz and 2000Hz) the combination is DEAD.

Further, not all air bearings are created equal. I use porous graphite air bearings, which acts as a final damping filter.

"I think terry9 fails to realize that an air bearing and drive of any nature provide more than enough energy to get things going if the table is not well designed"

Think again. I suggest that you listen to an air TT that has been properly thought out.

@mijostyn 

After reviewing my earlier posts, I think that you were quite right to criticize them. Sorry for the aggressive tone in my response.

You may find more bang for the buck in a quieter TT than in signal processing. Ralph (of Atmasphere fame) often suggests spending a lot on the phono stage to the same end.

As a general rule, every active device (transistor or tube) in the signal path increases noise.

For example, I parallel the first (aerospace) transistors in my preamp to reduce noise.

@mijostyn

"with modern machining bearing tolerances can be very close to perfect"

Agreed. It’s the "close to" that tells the story. In the old days, bearings were machined fairly closely, and then rotated against each other in situ, with fine grit, to smooth them. The finest bearings were done with the finest grit. That’s exactly how the glass-stoppered reagent flasks from the chemistry lab were made - and they were literally air tight.

That’s also similar to how the billion dollar telescopes are made today, so I doubt that the practice can be improved upon with machining. With an air cushion, however ...

Thanks for your explanation of Raul’s point - it was opaque to me. To that point, a platter bouncing on an air column is clearly visible and audible. It can be tuned away by changing the pressure by a few psi. Ask me how I know.

Heavier than 20 lb is absolutely useful for inertia when the stylus is dragged through the groove, producing a variable retarding torque. It is also useful for resisting the irregular pulses of an electric motor, and the bearing noise in that motor.

I have tested this - with a 45kg platter, the precision 2W electric motor, run from a quadrature power supply, generates enough noise from these sources to be repeatably audible, as a slight HF glare of the CD kind. Removing the belt tells the story.

@lewm 

Agree with almost everything. But: a low torque motor (e.g. 2W - yeah, I know watts are joules/sec) simply lacks the torque to affect speed very much. It's barely enough to overcome stylus friction and belt flexion, so it's tiny irregular forces (noise) have little influence on a massive platter.

You note that 'tightness' of the servo is an issue. I do so agree. That's why I use an AC motor - an AC motor sets a constant pace, it doesn't try to correct the pace. The speed of an AC motor can be set very accurately and very stably with a quality power supply.

@lewm 

"Could be you are saying that to couple a low torque motor with a heavy platter is a good thing, because speed in such a design is primarily maintained by the rotational inertia of the heavy platter. "

YES. In my rig, the platter must be accelerated by hand, as the motor is scarcely strong enough to maintain speed. This is the 'quirkiness' that I referred to in my first post - if you don't mind a bit or quirkiness, you can improve sound and save money at the same time. The late lamented Tom Fletcher used this principle to great effect. I have one of his better efforts too, but the air bearing puts it to shame.

Agreed, the compressor must be in another room. Disagreed about intrinsic noise of the air bearing. Empirically speaking, the higher end Nottingham Analogue (improved to Dais specification and anti-resonance plinth) does not compete with the air bearing, so obviously the statement, "The amount of noise on the record far exceeds what even a mediocre belt drive makes," is false or irrelevant.

@lewm 

"The trick is to minimize the noise while realizing the gain."

Completely agree. Obviously active devices are essential. My phono/pre uses three stages of them.

My point was this: "Why introduce a host of active devices to reduce pops and clicks, when we know that pops and clicks are partially caused by instability? There's a good chance that the money is better spent reducing instability in the phono/pre, not least because every active device produces noise."

Perhaps I'm not being clear today. Is so, sorry about that.

It's a good idea to buy your analogue front end from one place, so that they can set it up properly. Unless, of course, you are already an adept.

IMO

"preferably with a member of the opposite sex sitting in the passenger seat.  "

PASSENGER SEAT?  Baby you're so square!

I find the impressions of the OP's friend to be quite plausible. In the signal path, every active device increases noise, and every reactance creates phase shift.

Too bad about the Florida show. Why not take a weekend in New York to hear some alternatives?

I agree with Dover about linear trackers / tangential trackers. There is no contest in my books - although I haven't heard any of the Durand arms - but they are many times the price. Do try to listen to an air bearing TT before you buy - and not just an air thrust bearing, but an air bearing which positions the spindle too - that is, air in all 3 dimensions, no friction at all.

I applaud you for taking your time. More fun, and better result.

@rauliruegas 

To repeat, "I don't think that you do know what his (OP) ears hear and what his system sounds like."

Could have added, "with his kind of music."

And no, I'm not going to help you derail this discussion.

I own one of those new designs. It's just not as good - in my system, on my turntable, with my tonearm, and with my arm wands - to my ears.

Matching cartridge to system is more than just considering effective mass of the tonearm. Setting up is more than VTA. When you spend time and thought and money to get it right, as the OP is doing, you get a lot further than if you omit one of those.

I don't think that you do know what his ears hear and what his system sounds like.

You are in a very good space. I suggest that for $2500 more you can avoid making a costly mistake and find audio Nirvana.

Take a listening holiday to NY and hear some turntables. Find what YOU like, not what someone else likes.

Also, suggest being clear about your needs as well as your likes. Do you need a suspended table? I don't; I live on bedrock, far from a highway. So I didn't pay for a suspension which I do not need.

What are your tastes? Do you like CD-like crystal brilliance (I hate it), or do you prefer a smooth, sweet, mellifluous journey? When tuning my air bearing turntable and tonearm, I found that most real improvements enhanced the latter.

How much hassle are you prepared for? How much quirkiness? If you are ready for even a modest amount of these, you can save a bunch of money AND improve a bunch on the sound.

Three basic technologies, each of which has adherents. Belt drive (technologically easiest, and IMO quietest), idler drive, and direct drive (every electronic twitch delivered faithfully to your ESL's). Get an air bearing if you can afford it - once exposed, there is no going back. Air in all 3 dimensions is friction-free and noise free, but costly.

Make sure that your choice of tonearm is compatible with your choice of cartridge. 

As for brands, consider some which do not advertise heavily, like Nottingham Analogue. Bit quirky but a wonderful sound - almost as good as my air bearing.

My system is all analogue, mostly DIY, with heavily modified Quad ESL's. Cartridge is Koetsu with diamond cantilever, tonearm is based on a Trans-Fi Terminator air bearing, heavily modified to accommodate the Koetsu.

Good luck!

OMG, I agree with MC. Anyone know a good shrink?

Air bearing tables are many and various - but all of them are expensive.

Mine is a DIY with air in all three dimensions. I did this with porous graphite bearing surfaces from the US company New Way, using the larger of their so-called thrust bushings. The best compressors for this purpose do not use oil (e.g. Juno) but are noisy, and should be placed in a utility room.

The air cushion is stiff and not a substitute for a suspension.

But the SOUND - quiet to the point of blackness. No noise at all. So clear!

To complete my thoughts, bearing noise in a turntable is not always recognizable. In a quality turntable, it can manifest as high frequency distortion on top of the signal, which appears to be clarity in the triangle or the harpsichord. But this is artificial, and becomes wearing.

When you hear an air bearing, preferably three dimensions of air, you hear an absence of this HF distortion, and the result may sound 'dull' - that is, until you realize that 4 hours have passed and you still want to listen. And you just don't listen to the other turntable with the conventional bearing. At all.

In a phrase: clear, but not analytical.

No maintenance problems with my setup. Several stages of air filtration solved that. 

But there's more to the initial setup than for a conventional turntable, so be prepared for that. I suggest that you listen to some turntables, including at least one high end like Walker or Techdas, and decide if it's worth it. If not now, perhaps in 5 years. Whatever. It's your money and it's your enjoyment that counts.

Good luck - and tell us how it works out!

Congratulations on your purchase! Sounds like you hit audio Nirvana. Enjoy!

And don't pay too much attention to people who know which cartridge sounds best to you in your own system. Many of the most sophisticated audiophiles use Koetsu, especially with the diamond cantilever option. Then there are exotic options like field coil and strain gauge systems. Take your time, enjoy the fine system you already have. 

Don't recall if this topic has come up, but have you considered ultra-sonic record cleaning? Big benefits right away - quieter, more revealing - and big benefits delayed - low stylus wear.

My own stylus costs a lot to replace, so the US cleaning system is paying for itself twice over.

In any case, well done by you!

I use a lab grade US tank, made by Elmasonic. Runs at 80KHz or 37KHz - I use 80, and a rotating spindle to run one revolution per 9 minutes. Usually once through is enough, but some garage sale specimens have required 3.

Two threads might interest you: one here on Audiogon by antinn, a high class expert in cleaning technology. The other is a long thread on DIYaudio. Turns out that 80KHz is a really good frequency for records.

The reasons you might want a lab machine are: 80 KHz, internal heater, enough consistent power, and generally meets spec. As you know, lab equipment has to meet spec or there is Hell to pay. Consumer audio, not so much.

Bit of a DIY approach, but that's my style ...

Thanks @pindac  . Could not remember the exact reference. VERY useful.