New TT ideas please

Pauly,

Sorry for not explaining the Newton reference in my usual mind-numbing detail. Still, let's keep Michael Moore out of this. I don't know what kind of tables he likes and you probably don't either.

The problem I've noticed with suspended tables (again, not including the more expensive ones, which I haven't heard) had nothing to do with floor- or air-borne vibrations. It resulted from the suspension allowing plinth movements in reaction to cantilever excursions and arm movements. This sapped energy from the cartridge, slewed and slowed transients, muddied bass, etc. Sorry, but that's what I've heard. More than once.

Just yesterday I received this email from a friend who just received one of Thom's tables (switching from an Oracle, actually):

Toms bang more. Kick drums hold their decay but the low end and transient response is lightning fast especially for such a massive table.

I chuckled at that last, since it is the precisely his new table's mass and stability which give his arm a stable platform, which allows the cartridge to perform better.

Hatari,

I have a friend with a Clearaudio Master Ref (I think, the one with three motors and three rubber belts). He replaced all three with one Teres motor and one non-stretchy belt, and reported better pace and cleaner, faster transients.

Acrylic? Any stucture (platter, plinth, whatever) made from a single, homogenous material is going to resonate more than an identical structure made of a mix of different materials. Materials boundaries break up and reflect energies, so more materials can result in more energy dissipation. Different materials also absorb and release energies at different frequencies. With proper implementation all the above is to the good, since it will lower the noise floor of the table. Acrylic is used because it's easy to machine and relatively cheap - and many people like its looks. Teres used to offer all-acrylic plinths and platters. They stopped because they couldn't get the performance they were seeking.

The only weakness I can think of in a Redpoint (which I haven't heard) is that floating arm pod. Puts you at risk of unintended and possibly major cartridge realignments, possibly without noticing. ;-) If you can deal with that, I'd say give one a listen. Having a dealer near is a huge benefit, better than all the internet chats in the world!

Best,
Doug

Hatari,
Dougdeacon has hit- what I'm talking about- on the head. The Lenco is a fabulous machine in every respect to timber, rhythm, pace, tapping your feet, lovely clear highs, seperation of instruments, nuance of voice and feeling. It seems to do evrything right.
The Lenco platter is 8 pounds of machined aluminum, and, as opposed to belt drives, is engaged when an idler wheel comes in contact with it and a spindle which is spinning at a high torque provided by the small, powerful Swiss motor. Vibration of this motor should be absorbed ny tthe plinth design and materials.
Dougdeacon has the words to articulate what it is that makes this table a WORLD CLASS player, when properly plinthed and armed. Your Koetsu just might fall in love.

Doug,
I am sorry I cannot agree with your assesment of suspended tables. Basis units will give you plenty of slam and low end. I have also found them to be quick, nimble and very natural sounding. I have owned both fixed and suspended and the Basis has ended up being the best. I think maybe it might be the bearing on the table and the arm.

While I agree with Doug's comments I also agree that they may be a bit oversimplified. As is often the case it's all about compromise. A stretchy belt does have all of the problems that Doug points out. But the flip side is that isolation from motor cogging and noise is also very important. For a given motor and platter combination there will be an ideal amount of coupling. And that ideal will vary widely.

The important factor is how much cogging the motor exhibits. When you start with a motor that has low cogging the motor can be more intimately coupled to the platter resulting in some major benefits. Motor isolation is only good if it solves a bigger problem than it creates. Much better to start with a motor that does not need isolation, or at least very little.

It's a similar compromise when it comes to torque. High torque is a very good thing when it is tightly coupled to the platter. It's the only effective method for eliminating the effects of stylus drag. The higher the torque the better. However, in the real world higher torque (good) almost always comes with higher cogging (bad). So as Thom pointed out the challenge is to find an ideal compromise. As with isolation using a motor with lower cogging moves the ideal torque higher with it's associated sonic benefits.

A good unsuspended table addresses the problem of floor and room vibration. It just does it differently than a suspended table. This is a common misconception. There is a big difference between "high mass" and "highly damped". Simply making a turntable heavy is useless and often makes resonance problems worse. A highly damped turntable is able to dissipate vibrational energy internally. So external vibrations are allowed to reach the turntable but are then dissipated once they arrive. The big difference is that energy emanating from within the turntable is also dissipated in a highly damped turntable. It is important to have a mechanism for dissipating internal energy as well as energy from external sources. Suspension has both beneficial and detrimental effects. And like motor isolation is only good when it solves a bigger problem than it creates. A highly damped turntable needs less isolation so in many (but not all) cases isolation ends up being detrimental. This is why most highly damped turntables tend to be unsuspended.

Chris

Doug This may a double post – I cannot see my prior response.

+++ Sorry for not explaining the Newton reference in my usual mind-numbing detail.+++

Actually you offered zero explanation and you still don't.

+++ It resulted from the suspension allowing plinth movements in reaction to cantilever excursions and arm movements. +++

Okaaaay. A couple of misconceptions here.

Cantilever excursions cannot make the plinth move. The plinth is hard coupled to the stand. In my case, the stand is on a concrete floor. So unless the tonearm has more mass than dear old earth, the plinth 'aint going nowhere'. Need to do some rethinking here Doug.

The LP rests on the platter, not the plinth. Relative movements between the plinth and platter/tonearm assembly are only relevant if they have sufficient energy to upset the tonearm/platter assembly. That would would require something like an hard thump on the rack; something that would send an unsuspended tables arm flying across the record.

Real movement of the platter + tonearm assembly is important. In real conditions, there is absolutely zero movement – the suspension is at rest (equilibrium). When sufficient energy is dump on the table to cause movement, a suspended turntable ensures said movement to be at a frequency that does not do harm. Unsuspended turntables feed all frequencies directly into the platter and tonearm. That will include all audible frequencies AND your tonearm/cart resonant frequency. Not nice.

Relative movement between tonearm and platter is important. Cantilever excursions will dump identical amounts of energy on tonearm platter interface on both suspended and not suspended tables. Any downward movement of the platter (which will be minute) on a suspended table is compensated by LESS upward movement of the tonearm. This is Newtons law. “For every action there is a EQUAL and opposite reaction.” Emphasis on equal.

A non-suspended turntables cantilever excursions effects the tonearm platter interface with EXACTLY as much energy as a suspended table. That is not black magic, but pure science. Due to the higher mass of the platter assembly, the energy dumped into it from a cantilever excursion translates into less movement. (again, no black magic but Newtons second law).

In other words, the energy is better managed by a suspended table. On a non suspended table the tonearm needs to deal with 100% of the energy, and being so much lighter than the platter assembly, will exhibit the maximum movement.

As for your friends comments, I can echo that coming from a unsuspended table to my Oracle. So my response would be to chuckle also – seems not everybody knows how to set up suspension (although I did find it straight forward)

BTW, I still have an unsuspended table. It sounds better on air bladders.

Kind Regards
Paul