"The tonearm is now the centre of this ‘Turntable System and is the most important element. It must be rigidly held on a base which is perfectly flat, non-magnetic and relatively immune to structure-borne and air-borne feedback. This base must ideally have no contact with mechanical or electrical interference and must under no circumstances, move or deflect in any manner.
This base should ideally have no contact with the drive mechanism of the platter or the plinth, sub-platter, belt, gears, idler-wheels etc.
This base should be an island."
What a vacuous discussion. Suggest if you believe this, then sell your turntable, motor and records and just listen to your arm.
Your statements above contradict themselves - for ultimate speed speed stability there must be no movement between the drive and the platter. For ultimate generation of music from the interaction of the stylus on the record, then there must be no movement between the arm mounting and platter.
Ergo the motor drive, platter, arm and cartridge must be coupled together in a closed loop system that is absolutely rigid and yet has no transfer of unwanted energy between them that smears the speed sound or whatever.
In fact there should be no cantilever suspension to ensure as much transfer of the signal as possible - much like a rally car where they remove all the rubber mounts in for the engine, gearbox, drive etc to maximise power to the ground.
|
I dont agree with pods but I have thought about mounting a cantilivered armboard off the plinth using 3 mini spikes machined from grub screws so they are adjustable ( for levelling the armboard relative to the turntable bearing ) and using a nylon nut and bolt through the centre of the triangle formed by the grub screws to anchor the board. This arrangement would give you true 3 point mounting, energy dissipation and levelling capability. |
Jonathan - nice to hear from a fellow 60kg SPZ plinth owner - only point I would debate would be the air suspension, still think the tt has to be grounded no matter how much mass you have in the plinth. Rf shielding in the wall & perhaps a sealed room with an assistant inside to turn the record over.. One point I note is the number of people who locate their turntables in resonant room corners or between the speakers where sound travels free and fast. |
Lewm, why not use monopods for your amps, with 1 foot - then we can start a thread on the best sounding elastic to balance them. |
T_bone -
I think you are wasting your time on this. This thread goes round in circles.
If I look at Halcro's system it astonishes me that for all the discussion on turntable set up I see the following issues in his system -
Turntables located on a large resonant shelf behind the speakers where there is massive feedback. There is effectively a bass trap where his turntables sit.
Gear stacked on top of each other rattling away ( yes electrical components resonate when on ).
He has a TV spewing out RF inches away from turntables and sensitive phono stages.
He has a massive glass coffee table bouncing off hi frequencies in front of the listening seat.
I also note that the speakers have huge lips around the edges which will cause a tunneling effect and restrict soundstage.
He may like a horribly discoloured sound who knows, but for me strapping a cartridge on with a rubber band might well sound better in this suboptimal set up. |
Halcro,
Whilst I do not like sprung turntables I agree with Dertonam you cant write them off. The key mistake most suspended tt's with belt drive have is that they have the motor drive on a different chassis from the suspended plinth on which they mount the platter/bearing/arm. If the motor is mounted on the floating plinth along with the arm/platter then it is possible to get speed stability - ie rigid coupling of the motor/platter/arm/cartridge loop is the key.
For isolation my non suspended high mass turntable is mounted on a wall hung shelf which lowered the noise floor and cleaned up the bottom end considerably over floor racks with various isolation devices. My floor is a sprung wooden floor, so you may not get that difference with a concrete floor. |
Wow - there are a lot of discussion points here - my points :
Sota - used to import these and my Sota Star Vacuum is still one of my favourite decks. It was far more speed stable than the Linn, Roksan etc. We use to rebuild the power supplies for the motors, knocking out the on board regulation of the papst motor and replacing it with better regulators. The improvement was massive, speed accuracy, organic wholeness of sound, but SOME CUSTOMERS DID NOT LIKE THE MODS BECAUSE THEY LOST THEIR WOBBLY BOTTOM END.
Raul - speaking from personal experience on my Final Audio ( 40kg platter ) I recently installed a wall hung shelf. Whilst the deck was in pieces, I cannot lift the tt in 1 piece ) I pulled the inverted bearing apart to check, clean and relube. The tt is 30+ years old and believe me I have seen more bearing wear on a 2-3 year old Rega, Linn, Roksan, Pink Triangle etc. There is virtually no wear, the oil is clean as a whistle. I use Motul V300 Power Racing oil which is very unctuous. I have seen it prevent a racing porsche which boiled the oil from seizing. The Final had Sine/Cosine wave generation for the AC motor along with infinitely adjustable speed AND adjustable torque 30 years ago.
I think the sad thing in audio is that the megabuck decks in many cases have been built to look different and the engineering is no better than decks costing a 1/3 their price. I think you nailed the importance of power supplies - I cringe when when I see puny power supplies on megabuck decks. Pure marketing rules these days.
Another great example is the L07D - look at the plinth design - many top end decks go nowhere towards approaching the level of detail in this plinth.
Notwithstanding that we cannot ignore the high frequency purity of a low mass tt - the best example in terms of high frequency extension for me was the Pink Triangle - woeful performance on speed accuracy but high frequency purity and extension to die for.
I prefer non suspended decks for speed stability - but the context is "within a reasonable budget". The Rega P9 is a great example of a low mass non suspended deck at a modest price.
The SME I still recommend to many friends and colleagues on the basis that it is a very good deck, a complete solution - tt/arm - and SME have been around forever. It is a lifetime purchase and an easy solution for a non audiophile who wants excellence.
Arm pods ( ugh ) - Halcro, why not use a decent engineers vice as a temporary solution for experiments. You can then have a nude rigidly mounted arm.
|
Halcro -
The easy way for you to fix the issue is to get 3 holes cut and threaded for machine screws ( grub style ) around the outside of the centre bolt in the arm board as wide as possible ( maybe just inside the edge of the tower.
Get some machine grub screws and get your engineer to put a fine radius tip on each.
That way you can level the armboard with the 3 tiptoes and just use the centre bolt to lock it down. You could go to a nylon centre bolt to get a 3 point mechanical diode if you like.
You can also check if the vertical bearings are parallel to the platter and adjust if necessary for errors in the arm with this system. |
Hi Henry,
I've mentioned the issue of incongruity between platter and armboard a number of times, but it seemed to fall on deaf ears. Your experience matches mine when I had the shop. Since most folk level their platter and assume everyone else is level, I suspect a significant portion of tonearms do not have their vertical bearings in line with the platter - probably losing about 40% fidelity in real terms. Imagine owning a Linn with a wooden armboard moving around as the temperature varies.
This is one big advantage of unipivots with self centering bearings..
The other incongruity I see a lot is the motor pulley out of level relative to the platter. When running a rubber belt I've heard big improvements from ensuring the motor pulley is dead level and aligned to the platter. |
Halcro/Lewm/Raul
You are all arguing the same points but at cross purposes.
We are measuring the groove and to measure it accurately there must be no movement between the tonearm mounting point and the platter/bearing.
Lewm's argument is simply that a rigid plinth connecting the arm and platter will minimise the risk of any differential movement.
The requirements for a nude TT approach are no different really - there must be no movement between the tonearm coupling and the platter/bearing. Placing the platter bearing on a shelf and placing the tonearm on a pod on a shelf simply means that the shelf becomes the plinth.
There are crappy plinths and there are crappy nude turntables.
Examples of crappy plinths are the Tin Sondek and the SME hollow plinth of the 60's built for the Garrard 301/401 ( they built and sold a shaker table ).
Examples of crappy nude TT's are the plethora of Garrard 301/401's running separate arm pods mounted on spongy feet that provide no rigid coupling between arm/platter.
An example of a good plinth is the Final Audio. The Final Audio has the inverted bearing/platter and gunmetal arm pod both bolted to a 40kg slab of superplastic zinc alloy that is inert - at room temperature this slab cannot be excited below 100hz, energy in this material is dissipated at a molecular level through grain sliding, it will be better than any shelf that is not of the same material.
Halcro - what category do you place the AC Raven - plinth or no plinth ? Are you going to fully nude the Raven ?
I would argue that the Record is King. That is the centre of our particular inverse. |
I can recommend floating the motor/platter in Jello. Dont knock it until you have tried it.
I found raspberry rather nice under the platter, but preferred melon fusion under the arm ( its a unipivot so it has eccentric taste ). My only concern is that I felt wild cherry opened up the bottom end on hard rock, but have settled for the more rounded and harmonically complete raspberry.
For my vintage Tannoys I found feather and down pillows fluffed up the sound just right. The trick is to place them asymmetrically to break up unwanted resonances.
For the amps, hydrogel works a treat. I used breast implants for a full and ripe sound. If you want the best the Tibreeze brand are excellent. These have a titanium coating but were discontinued in 2004 and are hard to find.
I'm still working on the cable solution at the moment. |
Halcro -
Have to concur with the wall hung shelf. This is one of the best bang for the buck upgrades for TT's of all persuasions in my view and well worth the time and effort. Biggest difference I noticed was a cleaner and more transparent bottom end. |
The Mitch Cotter that I'm familiar with had a sprung suspension just like a Linn, only more springs and controlled better with foam inserts, no pneumatics involved.
The main thrust of his design was to remove all the extraneous crap from the direct drive ( motor covers and controls etc ) which removed resonances, and the use of an extremely rigid and inert aluminium/polymer laminated chassis to bolt BOTH the arm and DD motor drive.
Some great ideas embodied in that design in terms of energy control and maintaining a closed rigid loop between platter and arm.
|
All the following readouts contain vibrations of higher frequencies (mostly above 1000Hz) which are able to be absorbed, reflected or dissipated (to a degree) within the normal provinces of footers, stands, isolation devices and depending on design....within the plinth, platter, feet and mass of the particular turntable.
Here is a readout with the Isolation 'OFF' and the turntable REVOLVING.
Here is a readout with the Isolation 'ON' and the turntable REVOLVING.
Here is a readout with the Isolation 'OFF' and MUSIC PLAYING.
Here is a readout with the Isolation 'ON' and MUSIC PLAYING.
Halcro, If I look at the Herzan readouts with and without the music playing, the correction is different. This would appear to show that the Herzan is effectively modifying the music signal playback due to the vibrations of the stylus by imparting a corrective response that has taken into account stylus vibration generated into the platter/TT. Thus the measurement of the groove by the stylus is no longer accurate because the Herzan is responding to the music and thus polluting the signal.. Could you give some consideration and response, thanks. Dover |
@halcro
Thanks for that - agreed.
Ideal would be TT in separate annex away from airborne vibrations.
For those that can't afford the Herzan I have previously had some success with sound absorption panels behind the TT in resonant environments.
|
@halcro I've noticed that both you and J.Carr have recently 'transferred' over to 'The Dark Side' by adopting the new Technics SL1200 DD turntable over your previously loved belt-drives.
The Empire in your case and the Final Labs and big Micro Seiki in Jonathan's. Halcro, As far as I know JCarr was using a Marantz TT1000 DD as a daily runner. His Final Audio TT has been in storage - last I heard he was wanting to build a new motor drive system because he found the Final too complicated due to the fact that the Final system requires an external power amplifier to drive the motor. Effectively you have a preamp (sine/cosine wave generator), power amp, interconnects and speaker cables plus external motor to drive the 26kg platter. Even worse, you can hear substandard amplifiers and cabling as clear as a bell which means you are up for decent power amp and cables plus the TT & controller. I use an Onix OA60 amplifier ( sounded much better than the Rowland power amp I previously used to drive the TT ) and all MIT cabling in my Final TT set up. Needless to say the Final Audio Research TT is not for minimalists. |
