Dear Halcro,
what I learned is that taking an active isolation vibration platform, Herzan or Accurion, the latter one is not really cheap, may establish an even less nervous and more relaxed sound stage. As I showed on my blog it is quite an investment but you will get back a lot. Great discussion and philosophy! Agreed Thuchan.... The effects on the upper frequencies are the most revealing I feel. All the records I have where the high-frequencies become brittle or screechy as the volume increases are now listenable and (mostly) enjoyable. I continue to enjoy your Blog Audiocirc ..... Wonderful equipment and comments. Keep up the good work 👍 |
Folkfreak, The Palladian is still performing exceptionally, I used to have issues with stylus muck build up but since getting an ultrasonic cleaner this is a problem I no longer have. I’m still waiting on a new arm board from EAR so I can drop the arm another .5mm which I think will be ideal but other than that no concerns. Where do you have yours riding relative to horizontal? At present I’m a hair tail up which is as low as my arm can go with the sub board I currently have to use I have my Palladian running a smidgen LOWER than parallel (at the pivot) so I think you may well find a further improvement when you receive your new armboard....? Good luck.. |
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Since i am not an engineer, the complexities of plinth and motor sub-assemblies and suspensions are largely lost on me. But I do believe that the key of vinyl is looking upon the cantilever stylus-groove contact as being analogous to a tire of a car being under load and being steered in a rough rut in a road. Allowing that tire to follow and negotiate the rut with maximum contact with the rough area in the rut without careening side to side or bouncing out is the goal. Constant speed is next. Freedom from extraneous noise is next. Pretty simple stuff.
We hobbyists sweat over turntable design and set-up because it is there to be sweated over. By that, I refer to the fact that loudspeakers are the opposite of phono cartridges in terms of being transducers but all of the compromises and settings have been pre-set for us by the manufacturer-other than placement-so we don't think about them much. For every audiophile that has given up on vinyl as obsolete, I point to their choice of loudspeaker and say, "perfect sound forever, huh?". That is before we even start with their choice of filtering algorithm and the compromises implicit in them. |
Dear Halcro,
what I learned is that taking an active isolation vibration platform, Herzan or Accurion, the latter one is not really cheap, may establish an even less nervous and more relaxed sound stage. As I showed on my blog it is quite an investment but you will get back a lot. Great discussion and philosophy!
|
Dear @downunder : The JC reference always was the SZ-1, he is in love with Micro Seiki. This TT more than a piece of enginnering " art " is a piece of machined " art ". Micro Seiki is not my " cup of tea ", to many design problems with.
Taking in count the JC prefrence for the MS designs is not " weird " that he is testing the mediocrity of the TT1000 that’s a MS design and builded by MS not Marantz. There are nothing that can tell us TT1000 is a must to have especially that Marantz choosed to use glass on the platter and even in the plinth, glass is way way resonant material and " forbidden " to use it in a TT.
In the other side and even that’s a DD its measures are really poor but you can pull the trigger for it.
Is out of my mind JC choose ( ? ) in the Marantz and if he modified other than use the carbon fiber mat that a little less resonant than the glass but resonant at the end. Yes, JC priorities/targets are different from the ones of some of us.
Regards and enjoy the MUSIC NOT DISTORTIONS,
R. |
@halcro Hi Ralph,
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.
Can you reveal why you have changed, and what the Technics does that the Empire doesn't? Actually I still run the Atma-Sphere model 208 (which looks for all the world like an Empire 208 but uses an entirely different plinth). However I also have a lot of respect for the Technics SL-1200G. We had one here in the shop recently; a customer wanted to install a 12" Triplanar on it and wanted to know if that was possible. It was. I took the machine entirely apart and since I've had a lot of experience servicing consumer electronics in the last 45 years, I was very familier with the older SL-1200s. The new machine looks the part, but is an entirely new design with many improvements. One improvement that impressed me was how much attention was paid to rigidity of the plinth, while at the same time applying five different damping systems! In addition, the speed stability is one of the very best in the world, being second to only the SP-10MkIII. Its a very impressive machine and anyone serious about high end audio and wanting a turntable should consider it. |
@halcro yes, we do share similar tastes in some regards
the Grand Prix Audio Brooklands shelf is not in any way springy or flexible -- once correctly installed and locked down it is completely rigid. The only compliance on the design is in the typical GPA sorbothane discs that sit under the shelf and with the Herzan I have defeated these by simply overloading them.
Furthermore in my current installation the shelf is not actually attached to the wall but is instead mounted on three dedicated studs that are not connected to the drywall, each stud is in turn damped by an ASC stud damper.
Herzan were concerned that this would be an installation that fought against the active isolation but I have had no issues. The main problem the active platform addresses is seismic disturbance from construction (plus traffic and quake of course) there are six active multi story construction sites within a two block radius of my house and the whole area is reclaimed wetland so not the most secure of foundations. All of my stands and my speakers are seismically isolated via roller ball type footers or Townshend podia
The effect of active isolation is to make the table sound more stable and secure. Peaks no longer overload, bass seems diminished but is in fact cleaner, lower and more detailed. Frankly all of the euphonic (and nice to listen too) distortions of LP playback are significantly reduced and my LPs sound much more like my digital system but with all the air, emotion and interior dynamics that analog always excelled at. The improvement is actually most obvious with mono recordings which become even more dynamic and clear. I would certainly put the impact of adding active isolation above either an arm or cartridge upgrade, it would be interesting to see if a sub $10k analog rig on a Herzan outperformed a $20k one without it, I suspect it would
The Palladian is still performing exceptionally, I used to have issues with stylus muck build up but since getting an ultrasonic cleaner this is a problem I no longer have. I’m still waiting on a new arm board from EAR so I can drop the arm another .5mm which I think will be ideal but other than that no concerns. Where do you have yours riding relative to horizontal? At present I’m a hair tail up which is as low as my arm can go with the sub board I currently have to use |
Halcro, As far as I know JCarr was using a Marantz TT1000 DD as a daily runner. That is correct. There was a TT1000 for sale on ebay a few years back for local pickup only very close to me. He wanted a second one. I was going to pick it up for JCarr and give it to the AU Lyra importer to ship to Jon in Japan. LOL - they were outbid on ebay by someone else. All his other turntables are in storage. cheers |
As far as I know JCarr was using a Marantz TT1000 DD as a daily runner. You're right Dover... My TT-1000 by itself has a little less mass in the platter system than stock (I needed to shave down the top of the platter to get a flat surface for the graphite mat to bond onto). Add the center clamp, and the net weight ends up pretty close to stock - not enough to warrant readjusting the servo gain. He goes on.... Dover, you have a Final Audio? So do I (grin). My unit predates the Takai-era Parthenon, but is new enough to have the SPZ plinth rather than the original granite. It also has the bi-phase motor controller. FWIW, Kitamura's preferred material for mat and clamp was chrome copper rather than gun-metal.
And then more.... Even on my Micro-Seiki SZ-1S, which has a 28kg machined stainless-steel platter and integral vacuum clamp as well as air bearings for the platter and motor/flywheel, I ended up keeping the air bearings engaged and defeating the vacuum clamp (although I did prefer to insert a mat between LP and platter surface). Impressive collection... That Micro is higher up the scale than the SX/RX-8000 I believe... http://www.thevintageknob.org/micro_seiki-SZ-1.htmlBut I wonder if he's gone over to the new Technics SL1200 in place of the Marantz...or is he a 'paid' mouthpiece......? |
@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. |
Hi Folkfreak,
We must be related.....
Palladian cartridge, Herzan.....😁
I trust you're still enjoying the Palladian..?
Your supporting shelf for the turntable is most unusual....
I can understand the reasoning behind it (assuming you have springy floorboards)....but perhaps you swapped one problem for another..?
Suspension systems (as I know from engineering) are designed to MOVE...😱
Not only side to side, but also up and down depending on the details.
I can well understand how the readouts are more severe than in my situation.
The Herzan in your case must really be earning its keep....👍
On the positive side, the differences when the isolation is 'ON' compared to 'OFF' must be night and day...?
Are you able to describe the effects you are hearing?
Regards
Henry
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Hi Ralph,
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.
Can you reveal why you have changed, and what the Technics does that the Empire doesn't?
Regards
Henry
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I'll jump in to comment only on an experience with air-borne interference with my turntable.
My listening room has a 5' wide alcove along one sidewall. Within that I constructed two full width shelves to place source components. This accommodates freestanding record storage boxes underneath.
Initially I placed my turntable at the far right end of the top shelf. Unconsidered at first was the result of the arm/cartridge being very near a corner as it's arc traced a record. One day I had reason to lean over the platter area while music was playing. I was startled to hear the amount of low frequency build-up in that corner.
Considering those air-borne vibrations were affecting my vinyl performance, I moved the turntable toward the left hand end of the shelf. Of course the table was still the same distance from the sidewall, but being close to the mid-point of the 5' shelf, the arm/cartridge now operated some distance from either corner.
The result was obvious with any music played at moderate to moderately high levels. It was overall much "cleaner", with greatly improved definition and reduce sonic smearing.
Just as we want to avoid corner placement for nearly all loudspeakers, I believe all component placements should follow the same guideline for best performance. And hey, it was free!
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The Herzan has been integrated in my system for 6 months now, and not
only is it the final 'piece' of the jigsaw for the 'Copernican'
puzzle.....but it singularly is the most significant contributor to the
elimination
of 'distortions' and the elevation of sound quality that I have
experienced in 40 years of
audio. That is because it is effectively acting as the plinth. The arm is now rigidly coupled to the platter, which is as it should be. |
Dohmann may know his onions, but that "shield" would seem to offer no more isolation than is seen with the typical Denon, Victor, Technics, etc, designs that also shield the platter by sinking it down low, nearly level with the surface of the plinth. It may be that for a belt-drive, such an elevated highly visible shield is needed to accommodate the need for the belt to circumscribe the platter proper. |
I also got me TS-150 directly from Herzan dealing with Tim -- a very easy process. I have posted the interference readouts from my installation as part of my system description ( https://systems.audiogon.com/systems/5707#&gid=1&pid=31) You can see from the traces that in my room I get a lot more background seismic activity than Halcro does. This is a wall shelf installation so that may explain why the main activity is in the vertical dimension. The time base for the scan is 165mS so the frequency of the activity is 10-12 Hz or so -- it strikes me that as this is close to the resonant frequency of arm/cartridge combinations it may be that eliminating this may be one of the reasons the effect of these active platforms is so profound.You can also see that in my setup I get some motor noise transmitted into the stand which the TS-150 does a good job of removing. My TT (EAR DiscMaster) is designed to prevent this noise making it into the platter (via a decoupled tension bearing and the give in the toothed belt) but it should help to also not have noise build up in the stand itself Anyway just wanted to add my voice to back up what @halcro says about the benefits of addressing the record player as a system and working from the ground up |
Thanks Shane.....
Not only 'cool'....the Herzan is a real listening experience for vinyl lovers.
I dealt with Reid Whitney directly at Herzan in the States.
He really knows his stuff.
Tim Rather then handles the production and delivery.
I paid what I had to plus 'extra' for a special larger top-plate (I didn't want to run out of room if I needed to mount some other 12" arms in the future) plus FedEx Delivery......it took 3 days from the factory for me to have it 👍
This is definitely not a cheap option Shane....
Thuchan is about to trial a cheaper version in Germany from Accurion...
Will be interesting to hear his thoughts.....
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Interesting thoughts Dover.... Watch this VIDEO on the Doehmann Helix 1 turntable when Mark Doehmann (who was head designer at Continuum for the Caliburn and Criterion turntables and also the Cobra and Copperhead tonearms) comes in to explain it (past the halfway mark). Apart from the other interesting design attributes.....the aluminium that you think is the platter.....is actually a 'shield' against Air-Borne Sound Transmission and the platter sits behind it....🤗 Mark knows his 'onions'...... |
Very cool Henry. did you get a decent price for the Herzan and where did your source it from?
I can pm you for ultimate details. |
@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.
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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. Not so.... The added vibrations with music playing is purely Airborne Sound Transmission. HERE is a readout with the Isolation ’OFF’ a record playing but the sound MUTE. And HERE is a readout with the Isolation ’ON’ a record playing and the sound MUTE. |
Eddy Driessen is one of the ''Dutch grandmastrs'' known by his ''Pluto'' TT's and tonearms. I am not the right person to comment on TT's designs but his ''form follows function'' TT's looks to me to satisfy most conditions mentioned in this thread. |
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 |
It's seven years since I began the Nude
Turntable Project and thus also formulated "The Copernican View of
the Turntable System".
In that time I have learned a great deal through practical experimentation and
listening.
The lessons are many but the most significant one I believe, is this:-
- Isolated
armpods around a 'nude' turntable is one of the most difficult (and
problem-frought) solutions to the turntable design imaginable...
There are only two advantages I believe, for this solution:-
- Ability
to easily adjust geometry for every (and any) tonearm
- Potentially
better sound
The pitfalls are numerous:-
- Stability
of the turntable
- Isolation
of the turntable
- Levelling
of the turntable
- Stability
of each armpod
- Isolation
of each armpod
- Levelling
of each armpod
- Maintenance
of the geometric relationships
- Elimination
of ground-loop hums
- Elimination
of EMI/RFI interference
- Cost
The fact that it has taken me seven years to fully resolve
all these issues (and the multitude levelling processes are still not perfect)
should be enough to discourage all but the foolhardy from following....
HERE is the final resolution
of my Copernican Nude Turntable...
You will notice that the whole assemblage now sits on a Herzan TS140 Active Isolation
Platform which weighs 28.5Kg(62.8lbs).
This platform in turn sits on a propped and cantilevered 33mm wall shelf made
of laminated stressed-skin MDF.
The circular blue plastic discs under the spiked footers are poker chips which
were needed to prevent a ground-loop hum caused by all the armpod and turntable
metalwork, conducting through the Herzan aluminium top-plate to the electronics
below.
These poker chips are Superglued to the Herzan aluminium top-plate to prevent
movement and 'lock' the overall geometry in place.
The Herzan provides sub-hertz active vibration isolation in all six degrees of
freedom.
Performance Details:
- Active
vibration isolation from 0.7 – 1,000 Hz
- Passive
vibration isolation from 1,000 Hz and beyond
- 90%
vibration isolation at 3.5 Hz
- 99%
vibration isolation at 10 Hz
- 99.9%
vibration isolation at 20 Hz and beyond
- Up
to 55 dB of vibration reduction beyond 20 Hz
This Active Isolation Platform has highlighted a major
weakness in the Copernican philosophy....
Because the armpods are separated from the turntable motor, they are all
subjected to the maximum Structure-Borne Acoustic feedback experienced by the
supporting floor/shelf/rack system.
With a 'normally' designed turntable.....the
tonearm mounting points are attached to the turntable's plinth and are thus
'shielded' from structure-borne feedback by the turntable's own isolation
footers and mass/material of the plinth design. The levelling of the arm
supports is also integrated with that of the plinth.
Here is a readout of the vibrations experienced by the Herzan with the Isolation 'OFF' and the
turntable/arm at REST.
The top line is vibration in the vertical plane and there are two directions of
horizontal vibrations below.
These vibrations are purely Structure-Borne Sound Transmission caused by the
flexural stresses in the supporting shelving material and are entirely ultra
low-frequency (2-10Hz). They are there ALL THE TIME....
These ultra-low frequencies can pass through and affect ALL materials
regardless of their mass or densities, and they are not successfully absorbed
or reflected by normal isolation stands, footers or springs.
Only specialised stands designed for applications such as electron microscopes
(able to provide isolation down to 2Hz or below) can prevent these damaging
frequencies affecting the turntable/platter/arm/cartridge interface.
Here is a readout with the Isolation 'ON' and the turntable at REST.
You can see how the Herzan has 'actively' absorbed and nullified these ultra
low-frequency vibrations and prevented them entering the turntable system.
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.
The Herzan has been integrated in my system for 6 months now, and not only is it the final 'piece' of the jigsaw for the 'Copernican'
puzzle.....but it singularly is the most significant contributor to the elimination
of 'distortions' and the elevation of sound quality that I have experienced in 40 years of
audio.
It must also have been a revelation to Frank Kuzma (who shares the remote armpod
design philosophy for his TOTL turntable) as in May 2017 at the Munich
High End Show he demonstrated a Herzan
(Table Stable) as a recommended part of his system. But as I mentioned....the Herzan is the last piece of the 'Copernican' jigsaw. Some of the initial 'pieces' have proven to be naive....for instance, originally I had the Victor motor unit (with its metal shroud) supported directly on Tiptoes. Whilst the sound was still good....I was disturbed that there might be movement of the turntable with this primitive supporting method. I thus designed a skeletal stainless steel cradle which I thought would prevent any possible movement. It didn't....and in the process I had removed the motor's original perforated metal shroud. This shroud (it turns out) was acting as a Faraday Shield (with ground wire attached) in protecting the platter from the motor-induced RFI/EMI which now beset the installation. It wasn't until I designed a new 8.1Kg (18lb) polished granite plinth, that I was able to reinstate the metal shroud (complete with ground wire) onto the motor unit and eliminate - Movement
- Ground-loop hum
- EMI/RFI problems
Now all of you are shaking your heads at my stupidity in not having a solid, heavy plinth as the 'de facto' starting position, knowing how many Threads there are extolling the virtues of heavier and heavier Panzerholz, slate, granite and lead-lined plinths..... I'm not sure if heavier and heavier is necessarily better and better.....but I may be wrong 🤔. In the current design, 8.1Kg of granite is the best I can do and I think it's adequate.....🤗 It's only necessary IMO, for the cradle/plinth to be heavy enough to prevent the constant centrifugal forces of the revolving platter being able to induce 'movement'. For Belt-Drive or Idler designs...I can imagine these forces (and thus mass of plinth necessary) to be greater. One thing I DID get right at the beginning, is the size and weight of the 11Kg (24lb) solid cast bronze armpods which surround the motor unit. These are immovable monoliths and are successful in keeping each arm motionless and rigidly clasped whilst providing total immunity from motor/plinth/platter noise and vibrations. This isolation of the arm-mount is a known phenomenon which Continuum tackled in their Caliburn turntable, by suspending and isolating with magnets, the tonearm mounting plate from the plinth proper. There are other isolated armpod designs which use lighter, taller and flimsier pods which, apart from defeating the purpose of the 'Copernican' concept....may be susceptible to accidental and/or vibrational movement. Those designs I don't accept, as conforming to the principle 😱. There are detractors of the isolated armpod solution (and some of them have been prominent in their opposition here, on this Thread). The theory behind their opposition is valid.....rigid connectivity between the platter spindle and the tonearm pivot is a 'sine qua non'. I agree with them..... These theorists usually share two traits:- - They have never had a functioning isolated pod in their home system
- They refuse to accept that the shelf/rack/stand/base on which the turntable and armpods sit, together with 'gravity' are sufficient to maintain a 'rigid' enough connection
They are entitled to their views and I am not about changing these... I however DO have a functioning isolated pod system in my home (alongside a normal 'all-in-one' turntable) and believe that they are wrong.
If the turntable 'base' and isolated armpods are sufficiently heavy, gravity is indeed enough (as it is with all the buildings in the world) to RIGIDLY maintain the required geometry without the detrimental effects of transmitted vibrations from the motor/belt, bearing and plinth to the tonearm. There are some notable advocates and adoptees of the 'Copernican' theory:- I don't believe that anyone could call these designers and manufacturers (especially Frank Kuzma and A.J.Conti) fools...... So here I am......seven years later with a turntable system I can honestly attest, is the best I have heard. And I have heard most of the acknowledged 'greatest' of all time....... Now I don't positively know whether it's because of the isolated armpods, the superb Victor DD motor unit or the Sub-Hz Active Herzan Isolation Stand that the results are so good....? It's most likely a combination of all three 🤗 Would I recommend others go down this same path....? In hindsight....only if an Active Isolation Stand was a 'sine qua non'.....and this elevates the cost greatly. But consider this....even WITHOUT the Active Isolation Stand....the sound quality is capable of exceeding that of 'Digital' by a large margin 👅 My turntable system (complete with admittedly expensive tonearms) is in the realm of US$30,000 (with the Herzan close to half the total). Expensive compared with the average turntable...yet not outrageous when compared to 'Uber Decks' like the Caliburn, VPI Direct, Kronos, Walker Proscenium, SME 30/2 or any of the 'Copernican' decks mentioned above. I think I'm finally done and am happy to offer help/advice to anyone brave or crazy enough to venture down the same path.....😎🎶 Happy listening.....
|
Inna, Despite the fact that Freud is dead we all(?) know that he would say
something about our 3 ego's. I myself fear the ''it'' the most. The other two
can impossible explain the number of my carts and arms.
|
Are you referring to the ground added to the pcb board or the external cage connection point?
The ground wire attached to the PCB did nothing to mitigate the RFI/EMI interference. With the Faraday Shield (metal shroud) in place and the ground wire attached.....the problem appears to have vanished. I'm not electronically/electrically savvy so can only report the effects.....it appears that the Faraday Shield 'absorbs' the electrical energy emanating from all the electronics (particularly the power supply) and the ground wire dissipates it from the screen. I used to keep the motor 'powered on' (but not operating) when mounted in the SS cradle as it tended to sound better than fully 'cold'. Within the constricted enclosure of the granite cylinder.....I found that the build-up of electrical energy if the motor was left on (without the Faraday Cage) totally destroyed the sound of the turntable rendering it unlistenable. As a precaution to the bouncing around of this electrical energy off the reflective granite enclosure.....I lined it with cork sheeting in the latest version to try some absorption.....🤔 |
halcro
Another important cure for this feedback problem is to connect the ground wire from the chassis to the preamp. Are you referring to the ground added to the pcb board or the external cage connection point? |
2 1/2 years since the last contribution and yet nearly 1.3 million views...😎 In the time since my first enthusiastic proclamation, I realise I may have been a little cavalier in my concentration on the arm-pods at the expense of the platter/motor itself. As most of us have realised after decades in audio......EVERYTHING matters.... I initially designed and had made, the solid bronze arm-pods and merely placed the platter/motor on tiptoes http://i.imgur.com/Xp97BF8.jpgWhilst the sound produced by this arrangement seemed to prove my thesis....others looked to improve on my platter support http://i.imgur.com/sPdkMWn.jpghttp://i.imgur.com/8BTXLIL.jpgRealising that the flimsy metal shroud protecting the motor unit was able to 'flex' as the platter spun....I designed a stainless steel cradle to more rigidly hold the turntable http://i.imgur.com/UuEyECm.jpghttp://i.imgur.com/Ui6trXd.jpgThis was an immediate improvement and I discovered that the Victor DD decks actually sounded better 'nude', without their protective metal shroud. In the intervening years I became a little frustrated at the tendency for this lightweight 'cradle' to be moved whenever I re-aligned a new cartridge (which was rather often 👅). The arm-pods at around 11Kg each, would NEVER shift on their spiked feet. I needed a 'cradle' with more mass, and thus was born the polished granite cylinder http://i.imgur.com/S97uGns.jpghttp://i.imgur.com/qUyVNA2.jpgThis change was as much a revelation as the bronze arm-pods.... It seems that even the SS cradle was able to 'twist' under the constant centrifugal forces of the spinning platter and this resulted in a loss of ultimate transparency and lower register control. No wonder the latest 'rave' turntable (Kronos) utilises counter rotating platters to neutralise this twisting force. https://s-media-cache-ak0.pinimg.com/736x/62/64/dd/6264dd2057a9132a141c8cfda552102d.jpgI feel a little foolish to have overlooked what must have appeared obvious to many for all these years....but the lessons have been learned. Not only must the arm-pods be massive and immovable....the platter/motor must also be held in a vice-like grip. Mass is one method of achieving this but there are obviously others....... A few problems were discovered during this last design exercise and they may be peculiar only to the Victor decks...❓ Whilst the 'nude' motor unit sounded better in my system....when I mounted it in the first granite cylinder http://i.imgur.com/xIGWxmM.jpgelectrical feedback of the 50/60Hz became apparent with the two tone-arms which were not in the 'normal' platter/arm universal relationship. http://i.imgur.com/ieD1q6s.jpgHere you can see the DV507/II tonearm/cartridge passing directly over the motor transformer. This was the most affected tonearm. The solution was to screw on the metal shroud which apart from protecting the delicate electronics and circuitry....acts as a Faraday Cage to block the RFI/EMI for the cartridge http://i.imgur.com/UAEMFj7.jpgAnother important cure for this feedback problem is to connect the ground wire from the chassis to the preamp. With all systems go.....time to sit back with a good Scotch and enjoy the fruits of my journey...🍹🎼 |
Lew, you just described what I have evolved to with my own design. Hopefully now my local woodworker can turn it out for me. |
Lewm,
And the humour was appreciated.
As always... |
Lewm,
It sounds interesting and I'd be interested to hear about the outcome of your experiment. The closed loop arrangement is precisely what I'm trying to test while optimising the isolation in light of other decoupled approaches.
Experientially, (as everyone is probably aware) I am convinced by the performance of an SP10 on pneumatic footers with a decoupled tonearm arrangement: the sound is exceptionally good and greatly exceeds all of my prior analogue experiences. However, I am really only interested in obtaining the optimum performance from my gear and that could very well lead me to share your beliefs - even though I remain quite dubious. I will give it my best shot and see what that brings.
As always... |
Dgob, Sometimes I go for humor ahead of substance. Just kidding. We all know where I stand on the issue of plinths. I have done the work to reach my conclusions, so I feel ok as regards my own preferences and my own system. However, I am beginning to think about an inert plinth that provides a lot of mass mostly under the platter/motor assembly, so there is a minimal "deck" extending out around the platter periphery. Then a pod for mounting the tonearm, like the ones some of the guys have built, that would be firmly mated via a structural member, back to the main plinth. A few commercial products are built that way. I do not back off my contention that a closed loop connection between the tonearm bearings and the tt bearings is desirable, as Dover mentioned. |
Lewm,
All too confusing an analogy for me. The SP10's peritoneum would surely be the motor case rather than the additional plinth!
Designs seem to vary but operational excellence needs to be assessed in the light of the object and function under consideration: 'just as' arthropods function well with an exoskeleton but I function best 'keeping mine' internal.
I'll just press on with my efforts to discover how the SP10 and its associates function best. Who knows, when all is said and done, I could end up sharing your anatomically grounded perspective. Time will tell.
As always... |
Dover,
Yes, and thanks for helping with my ongoing considerations, research and experimentations. Of course, Cotter's floating (aluminium/polymer laminate) baseplate and attached platter was decoupled from the main chassis. My point was that the polymer fillers and springs that sat against the baseplate served a similar function (albeit in a far less efficient way) to the pneumatic footers against the bottom of the SP10 regarding resonance control.
I didn't discuss the dismantled motor that many have already considered regarding Kenata's design etc. I do feel that the potential gains of that aspect of Cotter's approach are accommodated in a simpler way by the already noted plinth-less and pneumatic support approach, however.
Much more reflection and experimentation to be had but progress seems promising.
As always... |
Banquo363,
Many thanks
As always... |
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.
|
Dgob: your link has an errant period at the end of the url; delete it and the page loads. |
Dgob, Just as the peritoneum was once seen as a necessity to keep the stomach, spleen, liver, intestines in their proper place. I am keeping mine.
Henry, Good one, re "Tom Henrys". |
Sorry,
Just to note that the use of pneumatic footers has its antecedence in the Mitch Cotter approach that found such acclaim decades ago. However, we're adding the potential benefits of the decoupled tonearm - in our current plinth-less and decoupled set ups.
Very little seems new regarding mechanical management (the use of pneumatic footers and magnetic footers aside) but new developments regarding materials (Panzerholz, aluminium/acrylic sandwiches, viscoelastic materials and the like) do offer interesting possibilities to such old discoveries. But I begin to ramble.
As always... |
Hi Halcro,
I don't understand why it wont load. However, if you google Audio Qualia you can find the relevant plinth related sections. I've also found some use in 'The Practising Scientist's Handbook', written and compiled by Alfred J. Moses (Van Nostrand Reinhold Company, New York, 1978) as cited at http://www.soundfountain.com/amb/sp10plinth.html.
Some explorers tend to emphasise that plinths were seen as a 'necessity' in order to keep the motor and innards of old TT's in place: as well as offering aesthetic advantages. With many of our models and concerns, this is obviously not a requirement and this (along with my own extending listening to a decoupled, plinth-less set up) leads me to suspect that the pneumatic footers and stand-alone arm tower for the Technics SP10 might be the optimum option - from a performance point of view. Anyway, I will give the plinth option my best efforts in order to adequately clarify the/any performance differences.
As always... |
'Hank' is purely an American epithet for 'Henry'.
Whilst I would have preferred it whilst growing up.......in Australia, it simply doesn't exist.
Although we do have a certain eccentricity in knowing the famous actor Tom Henrys who appeared in Sleepless in Seattle? |
Hi Dgob,
Unfortunately your Link does not lead to the page you suggest?
Are you able to re-load? |
Correct Lew, my father's name was Henry and everyone called him Hank. |
"Hank" is an apparently American nickname for someone whose given name is "Henry". Thus, the famous baseball player, Henry Aaron, is better known as "Hank Aaron". Now you mention your unfamiliarity with "Hank", I am not sure that they use it as a nickname in Oz, either. By the way, there is nothing pejorative about it. Henry/Hank is probably off somewhere with a pint of Foster's, ever since Adam Scott won the Masters. One of my Australian friends emailed to me that he was in tears over this victory, the first for an Aussie. |
Hi All,
One of the useful sources that I have found for designing my own (experimental) floating plinth is: http://qualia.webs.com/plinthbuilding.htm.
Although obviously not the last word on the subject it has some useful suggestions that might help other explorers.
As always... |
To be precise: what a niggling correction. According to
Frege the same tought can be expessed in different ways.
Otherwise we would need to surpass computers in exact
repetition of the words sequence. I should not use
quotation marks however. But for the foreigners among
us; what is a Hank?
Regards, |
To be precise: "Rumors of my death are exaggerated."
Henry, I may start calling you "Hank". |
Lewm did you know that Copernicus merely revived an idea of the ancient Greeks about a heliocentric universe Yes: Aristarchos the Samian. Info acquired recently thanks to my kids... Until then, Samos was an island (it still is) and produced very goodwhite wine (muscat, "AOC Samos"). |
Dear Henry, Yes you deed and this is not called 'humour'
but 'belittle' in literally sense. Humouros on the other hand
was Lew's response. I wanted to make him a compliment
but made a typo: 'this Lew is a smart gay'. His answer was:
'the rumour that I am a gay is exaggerated'. He borowed
this phrase from Mark Twain who was suprised to read
in the paper that he passed away: 'the rumour that
I am death is exaggerated'. Aussie humour? You must be joking .
Regards, |
