There are possibly several things going on with a copper mat. My Final Audio has a 4.5kg copper mat - the copper mat in conjunction with the 15kg aluminium platter provides bi-metallic damping, tapping the platter with and without the mat demonstrates the effectiveness, and is also a calculated energy path for the stylus/record by the designer to provide a mechanical ground. All other mats I have tried are significantly inferior on this particular tt.
Vintage DD turntables. Are we living dangerously?
I have just acquired a 32 year old JVC/Victor TT-101 DD turntable after having its lesser brother, the TT-81 for the last year.
TT-101
This is one of the great DD designs made at a time when the giant Japanese electronics companies like Technics, Denon, JVC/Victor and Pioneer could pour millions of dollars into 'flagship' models to 'enhance' their lower range models which often sold in the millions.
Because of their complexity however.......if they malfunction.....parts are 'unobtanium'....and they often cannot be repaired.
TT-101
This is one of the great DD designs made at a time when the giant Japanese electronics companies like Technics, Denon, JVC/Victor and Pioneer could pour millions of dollars into 'flagship' models to 'enhance' their lower range models which often sold in the millions.
Because of their complexity however.......if they malfunction.....parts are 'unobtanium'....and they often cannot be repaired.
Showing 50 responses by dover
Hi Halcro - I suddenly realised from In_shores post that my 4.5kg copper mat is used with the recommended 1.8kg gunmetal weight. The key to successfully using a copper mat is probably the use of a weight in combination with it. Some of my friends have used Goldmund Mats with their SP10 MkIII's with some success. Have you thought about trying the original thicker Acromat or Graphite - these would be worth trying in my view, perhaps along with a lighter record weight. On the Goldmund Studio's a couple of mates had ruby thrustpads made - maybe its worth thinking about whether you can improve the existing bearing. ?? |
For those of you that have platters that have a raised lip - it is a very easy job for a competent engineering workshop to remove the lip ( without upsetting the balance) which would enable you to run any platter mat, or alternately reduce the height of the lip so the record does not touch the aluminium platter. |
Thucan - it is very simple.The stylus is measuring the groove. To accurately measure the groove the platter and arm board must maintain a constant relationship. They must be rigidly coupled via a close loop system to ensure there is no differential movement between the two. Imagine trying to measure the length of a piece of wood with the 0 point of the tape moving back and forth. A similar case can be argued for having a rigid closed loop between the motor and platter. Physics tells us that where a platter/arm are not rigidly coupled to the motor drive, then there will be speed instability. Examples are 1) Where people put TT's on air platforms and the motor is on another table 2) The motor is mounted on a chassis and the platter/arm are mounted on a suspended suspended sub chassis. |
Pod Stability 05-11-15: RichardkrebsA perusal of your numbers shows they have failed the sound check, and here is why - 05-10-15: Richardkrebs This turntable was indeed my Final Audio VTT1 - which has a 26kg platter system - Platter 15kg, Subplatter 5kg, Copper mat 4.5kg, Clamp 1.8kg all designed to be used together to provide optimum clamping and energy dissipation to ground from the record. An AC motor, driven from a sine & cosine wave generator and Onix OA60 power amplifier drives the platter via a silk thread. To be clear what was being measured in my post on the Timeline thread – the 2mm lag was generated by setting the TT speed with no stylus playing and then measuring the lag when playing. A 2mm lag at a radius of 400mm is a speed error of 0.08% If I set the speed with a record playing, which is my normal procedure, then there is no speed error at all as measured on the Timeline, and therefore the variation in stylus drag due to music playing is an immeasurable % age of the total drag. If we assumed that the variation in stylus drag is plus or minus 20% of the total drag (remember it is not registering at all on the timeline), then the string drive Final Audio VTT1 has at worst about half the wow and flutter of an SP10mk2, and about the same as an SP10mk3, without the induced negative effects of the servos. Another small matter to correct re your post on the movement of Halcro’s POD – 05-10-15: RichardkrebsThis is wrong. If a chunk of mass is removed that is in front of the feet (closer to the platter than the centre of the pod ) then the centre of gravity of the pod shifts back AWAY from the platter. This INCREASES the resistance to tilt. In summary, your maths is wrong because your calculations are based on a misinterpretation of my Timeline test results.. When the 26kg platter speed was set with the stylus playing, there was in fact no measurable retardation. |
Ct0517 Thank you, the ET2 I Beam is an excellent example of an I beam - no plywood, no lead or glue, just a piece of plastic with flanges top and bottom to give axial and structural rigidity - the whole piece being an extrusion to form the I. Richardkrebs may have forgotten what the ET2 I Beam looks like as he has removed the decoupled I Beam from his ET2 and replaced it with a much heaver M10 bolt, thus removing one of the key patented benefits of the ET2 design, the decoupled counterweight which was designed to keep the high horizontal mass of the ET2 as low as possible and minimise bass peak resonances. The ET2 is an excellent example of using I Beams and large thin walled tubes to deliver a light but rigid structure. |
Lewm, You might like to try a copper mat on your SP10 if you haven't already. In a direct comparison of the L07D stainless mat, Boston, and a few others - the copper mat came out as the most complete in my experiments. A word of caution - for DD turntables mats should ideally weigh the same as original as the speed servos are optimised for the mass of the standard platter. For example in the L07D the manual carries a warning that if you run the platter without the mat the servos will not work properly. |
Fleib - please explain what doesn't add up. If you read my post I referred to the Goldmund platter, not mat. There is no difference between your post and mine. Here is an example of the vagaries of mats - my final Audio VTT1 has a 16kg aluminium platter designed to work with a 4.5kg copper mat & 1.8kg weight. My Platine Verdier has a 15kg aluminium platter. Both are solid cylinders in shape. On the Final the original copper mat has never been bettered, yet on the Platine Verdier the copper mat sounds awful. On the Verdier I use a Counterparts System Mat ( distributed by Sota in the 80's) that is methacrylate with an embedded layer of barium lead. This is much better on the Verdier than the Goldmund mat you refer to. Conversely the Compositions mat sounds awful on the Final. I think we agree on the turkey shoot, but there is some science behind what we hear. |
Fleib - both the Final designer and Goldmund have clearly stated their design goals. In the Final design their goal is to dump excess energy from the stylus/record interaction to ground as fast as possible. They eschew any form of soft materials - rubber, plastics etc. Kenwood had similar goals with their L07D. Goldmund have a similar design goal of dumping energy to ground as expoused in their publications on their mechanical grounding systems. If I recall correctly Goldmund's use of lead in the platter was more about adding flywheel mass than the damping properties. As far as the Transfi goes, I have listened to it at length on both an SP10 & Garrard 401 ( with $15k of arm& cartridge ) and in both instances it was vastly inferior to either a copper ( TT weights ) or stainless ( L07D ) mat, missing big chunks of information and smearing notes. Unfortunately with mats most folk use them like cables - as bandaids for system deficiencies rather than try to work out the best solution. |
Fleib, Many years ago my friend took his bog standard L07D over to Richardkrebs who at that time had a heavily modified Goldmund Studio. Despite the Goldmund having had many power supply and other modifications and an ET2/Monster Alpha cartridge and the L07D a cheap moving magnet - the L07D highlighted significant speed problems in the Goldmund, particularly in timing and coherency. The Goldmund by comparison sounded like it was lurching around and struggling to get over the line. This is what I believe prompted Richardkrebs to dump the Goldmund for the SP10mk3 that he now runs. I believe that Goldmund had the JVC motor. I have heard the Krebs modified SP10mkII and to my ears it is similar to the Goldmund Studio, well down in performance compared to the L07D and SP10Mk3, again in loss of timing and coherency. I think it is significant that both the L07D and SP10mk3 utilised higher mass platters than their earlier DD's to assist with speed stability. And yes by DJ I meant radio stations and the need for quick and accurate queuing. One further thing to be aware of - out of the five people I know with L07D's, only one has had no "apparent" problems - quartz locking not working properly, hum, noise being the most common issues. So when we audition some of these decks today it is possible that we were not hearing them optimally as they were designed simply due to ageing and drift in components. Lewm I have heard both the L07D and SP10mk3 with and without the Krebs tweak and agree with your summation, the proviso being that the TT's have been serviced thoroughly and are performing to spec. Bear in mind though that the SP10 requires a lot of work to get it sounding ok - new plinth, mats etc. |
There is only one way to "redo" old solder joints, and that is to completely strip and clean off ALL of the old solder from both the eyelet and the component. This is incredibly tedious and time consuming. Some folk just wave a wand, melt the original solder and then add more solder - this is a recipe for disaster. |
10-23-15: Fleib1. There is no such thing as absolute speed. Speed is relative. 2. Wow or flutter can be measured with a rotary function generator connected directly to the platter - this is the method Thigpen uses. 3. Using a record with a fixed tone is prone to error. Any eccentricity or imprecision in the surface of the record will generate wow or flutter. 4.The timeline only measures the arrival of a single point on the platter at the same place at each time. It does not measure what happens in between. If you take points 2 and 3 above into account, then when playing records there will be more wow and flutter generated by the arm/cartridge than the TT itself. If you want to relate Direct Drive speed stability to sound quality consider this: Analogue wow and flutter is similar to digital jitter. Testing of digital systems as regards temporal errors and the effect on sound quality has yielded the following - 1. The lowest level of jitter that affects sound quality is 5 nanoseconds. 2. Using sine waves for testing showed most people could hear errors down to 10 nanoseconds. 3. On recorded music people could here down to 20 nanoseconds. I have seen some studies that suggest temporal recognition in the brain is triggered at around 4 nanoseconds. There is no way that the error correction circuitry from these vintage decks is fast enough to be inaudible. If the listener thinks that their TT "sounds" more speed stable than anything they have heard before, then their perception of their current turntable on its relative merits is limited to a relativity to the inferior tables that they have previously used in that particular system. |
Halcro - 10-23-15: HalcroThat is not correct - point 2 in my post you refer to highlights that the Feickert test record can be prone to error - evidenced by the fact that the weighted averaging process is supposed to account for eccentricities in the record ( see Feickert for confirmation ). 10-23-15: HalcroIndeed, you have confirmed that the Feickert is not accurate enough to quantify the micro changes in speed between the test intervals. I would also remind you that in your earlier testing you indicated that you got different results if you rotated the record a quarter turn. 10-24-15: RichardkrebsIn Fremers testing thus far he highlights the vastly different shapes of the raw trace between the Caliburn and the Onedof even though they measure similarly, indicating differences in micro timing vs macro timing. I would also expect for example differences in the shape of the traces according to motor type - AC motors tend to self correct sinusoidally, whereas DC motors tend to correct trapezoidally. An important point is that we can only do true comparisons where the testing instruments, protocols, and environment are constant. In other words comparing your results to Fremers is not scientifically valid. There will be differences in the test records, there are errors integral in the iPhone/computer apps that vary depending on model, and many other variables. |
Halcro, thank you for taking the time to confirm that my original assertions on the disadvantage of using a test record to measure Wow and Flutter were correct. 10-23-15: DoverAs Marcus Ribi from Feickert says.. 10-26-15: HalcroIn the final analysis the key sentence in Feickerts response is "tries to best filter away the regular changes coming from record eccentricity to provide best results". The Feickert software uses algorithms to calculate and remove errors generated by eccentricity. These are an approximation at best. If you had a faulty turntable with a regular error with each rotation, the averaged WOW & Flutter reported could understate the true WOW and Flutter if the algorithm ascribes the resultant speed issue generated by the fault to eccentricity". |
10-26-15: Richardkrebs Assuming for arguments sake that this number is correct, then given that record spindle diameters can vary from 7.09 to 7.21 then we are looking at errors of 0.2% even before we take record eccentricity into account. Richard, given that most records are eccentric to some degree, could you explain why you have increased the horizontal mass of your ET2 by 300% adding lead to the spindle and removing the decoupled counterweight, when it is clear that increasing the horizontal mass will increase the wow and flutter on playback by a significant degree on eccentric records. The testing I did on my ET2 with removing the counterweight resulted in audible degradation of the sound. |
Lewm - No they are not in agreement. Halcro does not accept that the deviations in the sine wave are wow and flutter ( as explained by Feickert ). Richardkrebs argued that the spikes were speed corrections generated by the TT error correction, but they could be caused by many things, all we know is that they are speed deviations. Other than eccentricity wow and flutter can be caused by imperfections in the record surface ( you must have heard of warp wow ) and tonearm/cartridge issues. So your statement that "The remainder would constitute w and f due to the tt only" is not correct. |
05-10-15: RichardkrebsThis is wrong. When examining dimensional stability one needs to take into account materials engineering. If aluminium is produced by a rolling or extrusion process, then the dimensional stability is directional - much lower along the roll and higher across the roll. Furthermore if a metal is produced by a casting process then it is usually substantially more dimensionally stable than that manufactured through a rolling/extrusion process. The L07D is a cast foot. I think you will find the engineers went to great cost to produce a cast for this very reason. Richardkrebs - one thing puzzles me. You made your turntable from acrylic sheet, which has a Youngs modulus 60 times lower than steel ( which means it is 60 times less rigid ) and has a temperature coefficient of expansion 6 times higher than steel. Given that your TT is a triangulated structure and the SP10 motor is mounted in the centre of the acrylic sheet, it would appear that you have mounted your SP10 motor on a trampoline. This seems at odds with your stated design goals of absolute dimensional stability. Furthermore, on the plinth you made, the arm is mounted closer to one of the three structural legs. So not only is your TT plinth expanding and contracting at a higher rate than say a cast chassis like the Melcos & Microseikis of this world, or even the L07D, your VTA is constantly changing due to the large differential in vertical structural rigidity between the centres of gravity of the SP10 motor and the arm. In layman's terms in your plinth the SP10/platter will move up and down at a greater rate than the tonearm when excited. |
05-13-15: RichardkrebsBy no stretch of the imagination could you refer to your plinth structure as analogous to an I Beam. I have never seen a lead sandwich described as an I Beam in the time I studied Engineering at University or in the 5 years I spent working for NZ's largest timber company. The middle of an I Beam has high structural integrity in the vertical direction so that the beams do not sag. The top and bottom of the "I" provide the lateral stability. Your lead spacer has no structural stability, it is not possible for this structure to work like an I Beam. Plywood in of itself is not structural, it flexes a lot. Flex in plywood plinths is reduced by running multiple layers and a lot of glue, but they still flex. If you want stiffness from plywood you would cut the plywood into strips and glue them with the board vertical ( as is done in I beams ), like Albert Porters layer of panzerholz in his plinth. The panzerholz is not used in sheet form, it is cut into strips and glued sideways. |
Fleib - both the Final designer and Goldmund have clearly stated their design goals. In the Final design their goal is to dump excess energy from the stylus/record interaction to ground as fast as possible. They eschew any form of soft materials - rubber, plastics etc. Kenwood had similar goals with their L07D. Goldmund have a similar design goal of dumping energy to ground as expoused in their publications on their mechanical grounding systems. If I recall correctly Goldmund's use of lead in the platter was more about adding flywheel mass than the damping properties. As far as the Transfi goes, I have listened to it at length on both an SP10 & Garrard 401 ( with $15k of arm& cartridge ) and in both instances it was vastly inferior to either a copper ( TT weights ) or stainless ( L07D ) mat, missing big chunks of information and smearing notes. Unfortunately with mats most folk use them like cables - as bandaids for system deficiencies rather than try to work out the best solution. |
05-14-15: Richardkrebs Richardkrebs, that is not correct. if you used sheets of plywood stacked vertically to make an I beam your house would sag and probably fall down. The essence of an I beam as I explained in my post is that the vertical component has high vertical and longitudinal strength, but can be flexible in the lateral direction. It has nothing to do with the layers of timber in the wooden I Beam. In actual fact plywood as you understand it is not used in the manufacture of I beams. I Beams use a special construct of layers of timber running in the same direction to give the structural longitudinal strength. Plywood has the layers arranged with the grain crossing at 90 degrees with each layer. It might help if you look at a metal I beam to understand the concept - there are no laminations in a metal I beam, but if you removed the top and bottom of the I then the beam will flex like a sheet of metal. |
5-14-15: RichardkrebsRichardkrebs you described your plinth as a "form of I Beam". 05-13-15: RichardkrebsAn I Beam consists of a Web with a flange top and bottom. Your plinth that you describe has only a Web and no flanges. An I Beam without flanges is structurally weak, has no axial strength and will flex. Here is a link to help you understand how I Beams work.. http://en.wikipedia.org/wiki/I-beam There is no debate. The plinth that you built is laminated sheets of acrylic and lead and is not an I Beam, nor is it even a form of I Beam as you have claimed. |
Lewm - With the various mats the L07D stainless & Micro 180g Copper were very close on the SP10. It is possible the differences may be more to do with mass & the actual surface profile than anything else, since they are both high impedance type materials. People forget that platter mats are mechanical devices that not only provide an interface and base for the stylus/record, but also have significant impact on altering the resonant behaviour of the platter itself. In particular with aluminium platters, a metal mat such as copper/bronze/stainless will dampen the platter much more effectively than say acrylic or rubber. The reason is that if you combine two materials that are close in propagation speed then reflected resonances ( which end up back in the record and stylus) are minimised. Reflected resonances - whenever a resonance or energy passes through a material junction, most passes through but a percentage will be reflected back. The closer the materials in propagation speed, the less the reflected energy. This is why Goldmnd and others went the methacrylate way with platters to get the impedance much closer to vinyl and minimise reflections. In summary the mats on an aluminium platter are trying to bridge the vast difference in the impedance of vinyl versus aluminium. None of them will be perfect. |
07-13-15: RichardkrebsRichardkrebs, It is staggering that you would be performing turntable modifications without a thorough understanding how the TT works. It is fanciful to speculate that the Kenwood engineers designed "slippage" when torque is applied by using rubber grommets. It is more likely that they employed the grommets to reduce mechanical and/or electric noise within the suspended board and coils. To help you understand the L07D servo operation, here is a link to the owners manual - http://www.vinylengine.com/library/kenwood/l-07d.shtml Page 4 gives you an overview - the L07D uses a dual mode speed control system - if the speed error is below 3% the phase is controlled with a wide lock range and large phase gain. If the speed error exceeds 3% the servo controls speed rather than phase, and applies higher torque. When the servo mode switches from phase to speed control, the coupling changes from DC to AC to minimise influences from the motor drive circuit and motor offset. Clearly the L07D relies more on platter inertia and phase locking for coping with stylus drag unless the speed error is very high. This is quite a different design to the Technics SP10 solution which relies on a much more aggressive servo speed control system with the DJ market in mind – the ability to start and stop on a dime was more important to the Technics engineers than the Kenwood engineers. I have listened to many L07D’s and SP10mk3’s at length and in my view the difference in servo design and implementation forms a significant difference in presentation, particularly in timing and coherency. |
10-28-15: HalcroHalcro, read my post again - I wrote Richardkrebs argued that the spikes were speed corrections generated by the TT error correction, but they could be caused by many things, all we know is that they are speed deviations.The statement you ascribe to me was an argument put forward by by Richardkrebs. The second half of my sentence states clearly that my view does not agree with this notion. It is not I that has a comprehension problem. 10-28-15: HalcroThat statement is not correct. That is not what Markus says. Markus says quite clearly That's what the spikes are coming from: it's a superposition of eccentricity and "real" WOW and flutter.In engineering "superposition" is the overlapping of waves. It is very simple - the raw data graphs are the sine wave generated by eccentricity (a) PLUS the wow and flutter ( speed deviations ) (b). The software uses a notch filter to remove the sine wave generated by eccentricity. In a nutshell the deviations from a pure sine wave ( the spiky aberrations in the raw data graph ) are the wow and flutter as Markus says.. To verify this I went to the Adjust+ website and downloaded their manual. On page 37 Please note: most vinyl records are not perfectly centered. You will often see periodical fluctuations of speed at an interval of 1.8 seconds. This is exactly the time for one revolution at 331/3 RPM. In order to mask these effects, the recorded data is filtered using a steep 0.55Hz notch filter (results beneath "Filtered at 0.55Hz"). But please bear in mind that problems with the turntable bearing probably may also cause similar fluctuation patterns at 0.55Hz. These are also attenuated by the notch filter. Both values – filtered and unfiltered - are displayed.This extract from the manual confirms that the unfiltered graphs are a summation of both the wow & flutter due to eccentricity and the wow and flutter to to the playback system ( TT/arm/cartridge ). Guess what - in my previous post I stated if a TT had a fault that resulted in a regular speed deviation, like a faulty bearing, this would be assumed to be eccentricity and not reported in the filtered graph. The manual confirms this. Lewm, I do not intend to be condescending, but where errors have been made they should be corrected. |
And the winner is ..... Belt drive Onedof turntable. Richard - one final correction. Halcro keeps posting the VPI Direct Drive raw graph. 10-16-15: HalcroUnfortunately the raw graph Halcro posts is in fact the Onedof turntable. Here is the link to the original graphs - VPI Direct & Onedof raw data graphs Figure 2 is the VPI Direct raw data graph. Figure 3 is the Onedof raw data graph. Interesting to note that the smoothest raw data graph by a substantial margin is the Onedof TT with stretchy rubber belt drive and high mass platter. Fremers testing and listening notes that the Onedof and Caliburn turntables have similar absolute results, but different shaped graphs They sound substantially different in character, perhaps the raw data graphs go partly to explain it. This of course is conjecture only. |
Lewm - there is no proof that the Krebs mods reduces the number of error corrections. Krebs provides no evidence that his "mods" reduce the number of error corrections. Krebs cannot provide any testing data to support the claim. Although you say you cannot imagine anything better, it is worth noting that David Karmeli classes the SP10mk3 that he owns as a toy compared to his reference tables that include the Techdas, EMT 927, Goldmund Reference, American Sound & Thorens Reference. None of these are direct drives. I share a similar view to DDK as I have heard both the Krebs SP10mk2 and mk3 and they simply do not have the resolution that my Final Audio VTT1 provides. |
Richard, I have owned the Final for 25 years and in that time you have heard it once. I clearly recall your comment at the time which was "amazing". During that 25 year period I have also had the pleasure of owning many other turntables - various Sotas including Star Vacuum, Well Tempered, Garrard 401and 301 idlers, Pink Triangle, Oracle Delphi’s, Roksan and others. I have just sold my Platine Verdier. I have personally set up many tables including various Goldmunds, VPI’s, Gyrodecks, Aura’s, Mapleknolls, Micro Seikis and others too numerous to list. I regularly have listening sessions with audiophiles/music lovers, some of whom own Kenwood L07D’s and SP10’s and have no reason to replace the Final. I recently hosted a listening session which included the owner of a Micro Seiki SX5000 loaded with Graham Phantom’s who fully concurs on the relative merits of the above mentioned decks. As regards "dynamic speed stability", there is a reason your SP10 and Halcros Victor have servos and speed correction - the SP10 and Victor cannot hold speed without the servos running. If you turn the servos and error correction off, neither of these Direct Drive TT’s will run let alone maintain speed. The previous owner of the Final, Warwick Mickell was an opera lover, played harpsichord & wrote for The Absolute Sound magazine; pitch stability was a key requirement when he set out to select the best possible turntable, cost no object, in Japan, at that time. Warwick benchmarked the Final against the Denon DP100 Direct Drive and many other turntables prior to purchase - it was no contest. I’m sure there are other great turntables such as those I mentioned in my previous post - the EMT 927, American Sound, Micro Seki’s etc - that can give great musical pleasure. |
richardkrebsIt would appear then that you agree with me now. It is surprising that you could live with DD turntables for 20 years prior to "taming the jitter". With regards to "taming the jitter" - thats what the digital guys claim each time they release some new algorithms or technology. As I said to Lewm there is no evidence that your lead and glue mods to the SP10 reduce the number of error corrections per unit of time which is what he claimed. You may have slugged the sound but the error correction is still going on. Servos and error corrections are not irrelevant as you claim - these are micro adjustments to the speed of the motor and platter. This is why you hear "jitter" with all direct drive turntables ( other than yours of course ). |
Richard - Last time I looked under the bonnet of the oscillator preamplifier on the Final, there was a bit more than a capacitor. Time to move on and focus on direct drive. A direct drive motor turns once per revolution of the record. By comparison the Final motor rotates 54 times for each revolution of the record. This means that the error correction and servos in a direct drive application are constantly error correcting over a larger time period per revolution between poles. To put it into perspective a typical direct drive with say 8 poles has only 8 pulses per revolution of the platter compared with 218 pulses per revolution ( motor speed 1800rpm x 4 poles /33.33rpm ) with the Final. This along with the high inertia generated by the Final 26kg platter results in an audibly superior sound. This same principal applies to idler drive type turntables where the platter is typically driven from a high speed motor with small pulley driving a large platter. In engineering we call this gearing. Cutting lathes also use this gearing principle, high torque motors and high mass flywheel to achieve stability. |
Lewm - Life is a constant learning exercise, that is why I read and participate in these forums. I regularly listen to and enjoy music on all types of drive ( other than digital ). You are quite wrong on the Final - I would be disappointed if there were not a better turntable out there - because I enjoy the constant upgrade process and the joy of rediscovering old records in a new light when one accomplishes gains in the playback system. I do not claim it is the best, I simply haven’t heard anything better yet. There are many TT’s I still have not heard. The comments I have made in this thread are only related to TT’s that I have heard in depth. Ditto with Rauls MM thread - I still prefer MC’s but have gleaned much knowledge and tried a few new MM’s in the past year or two. I continue to listen to other turntables in my system - it’s enjoyable and usually learn something. A few corrections on the Final - it has a very powerful AC motor, no active speed correction. Speed is controlled by precision oscillators regenerating sine and cosine waves and a power amplifier to drive the motor. It has separate controllers for 33 & 45 and I can set the speed between 0 & 85 rpm on each as well as vary the level of torque applied. Speed relies on inertia (26kg platter), powerful motor and AC phase locking. As regards belt creep the Final uses silk thread - the stretch is negligible compared with rubber belts, otherwise I agree with your comments on belt drives (rubber) and so far the only decks that have approached the Final have been idlers. Speed and power wise, the most astonishing TT I have heard in the past couple of years was a Denon RP52 Idler. The owner, a DJ, demonstrated side by side with a Technics DD in the same system that you could could start and stop the Denon with a low compliance MC sitting in the groove and hear virtually no slurring of the music on start up. Doing the same test on the Technics DD resulted in much slower start up such that you could hear the music coming up to speed. I wish I had made a video of it. I suspect the EMT 927 would be in that league - huge torque coupled with a 50lb flywheel. The Technics DD motor used for driving lathes, the SP20, was designed specifically to operate in conjunction with the Neumann 60lb flywheel and has significantly more torque and poles than the SP10mk3 - this would be an interesting DD platform to listen to. |
Fleib 12/13/2015 Fleib, you are addressing this concern to the wrong person. A review of the posts since 2011 shows that is others who are starting discussions and making comparisons on belt drives in this thread. For example - Doron & Harold-not-the-barrel started a discussion on the Oracle BD in September 2014. Halcro, the originator of the thread, started discussing the merits of various BD’s vs DD’s and their relative Feickert speed test results and graphs in October this year. You and Richardkrebs were discussing belt drives with respect to Bruce Thigpens test results on wow & flutter in October this year. I have only responded to others
comments on BD’s since Halcros Feikert discussion in October.
The FIRST person to bring up the performance of the Final Audio VTT1 thread drive to this thread was in fact Richardkrebs in this post
My first post and only post in this thread on the Final Audio VTT1 thread drive in the 4 years up until October this year was a response to the misleading comments posted by Richardkrebs -
The SECOND person to bring up the Final Audio VTT1 thread drive in this thread was Halcro in this post -
Halcros comment flabbergasted me as the only mention I had made in this thread re the Final Audio VTT1 thread drive prior to his post was the single response to Richardkrebs post. Clearly some folk feel the need to question the performance of the Final Audio VTT1 even though I never raised it in the first instance, or even the second. You will have to ask them why they keep bringing it up in this thread, but if it is maligned, then I may feel obliged to respond. As to the subject of the thread “
DD are we living dangerously” then all turntables are relevant. In order to assess this proposition one needs a reference. For example, one could argue that the Linn LP12 BD presents a very good case for being the gold standard for "living less dangerously" as it is one of only a very few turntables where one can have the manufacturer repair and refurbish any turntable they have ever made. In terms of the Final Audio thread drive – mine is around 40 years old, used every day and has never broken down, ever. The oscillator preamplifier ( speed controller ) is completely original, never been recapped or repaired in any way shape or form. The only servicing required in 40 odd years of operation has been a re-lube of the motor and a change of oil in the main bearing every few years. Cheers |
HalcroThis seems a bit far fetched - a piece of aluminium 255mm will only expand by 0.0587mm for a 10 centigrade temperature change according to my calculations. Steel and bronze would be much less than this. Perhaps Halcro, since you design bridges, you could explain your maths. |
Halcro - indeed it is quite something to have designed a bridge. When you mentioned designing a bridge in your earlier posts I thought you were a dental technician, until I found out that you were an architect. I studied engineering at university and most architects only do a couple of basic engineering papers for their degree in New Zealand. As regards vibration - yes I agree it is an issue. The Final uses a superplastic zinc alloy chassis base that dissipates any vibration between 10 & 100hz at room temperature internally at a molecular level. Both the platter and arm pod are bolted to this SPZ energy sink to achieve both loop rigidity and deal with vibration. |
The airflow paths in the Victor TT801 are visible here http://audio-heritage.jp/VICTOR/etc/tt-801.html My suggestion would be to replicate the rubber mat in delrin which is easy to machine. There is also a TT801 vacuum pump on Yahoo Japan at the moment. |
Lewm 01-22-2016Lewm If you had "digested the thread thoroughly" as you claimed, you would have understood that jpjones has comprehensively researched and measured both the original circuit and components and has carefully measured and tested his new board at every stage of development. You are wrong to claim that he "seems to infer that his circuit is actually more accurate". Jpjones provides test results and scope data that support the published results. This provision of test data is a breath of fresh air compared to the faith based changes touted by others in this thread who provide no test data and furthermore argue that test data is not needed to support their claims. richardkrebs 12-08-2015 4:00pmIt is surprising that you, as a doctor, prefer to support unsubstantiated claims whilst trivialising others who have provided extensive test data that support their observations and claims. |
From a 6 Moons Review of the Walker...More nonsense from the marketing gurus of a typical audio company - materials do not have resonance, they have bulk properties which affect the resonance of the structure in which they are used. In the case of the Walker the composition, materials used ( including epoxies and any other materials ) and the manufacturing process itself will all affect the final resonant properties. |
Lewm, I showed my tech Halcros photos at the time and he said no problem - there is enough web info to work the Halcro circuit out and you can solder through the gunk if you know what you are doing. Having said that he has a Bachelors degree in Electrical Engineering and has been designing high tech electronics commercially for some years, not one of the self taught "experts" you often find in audio. |
Halcro - yes I agree, Acoustic Plan's view on the importance of wow and flutter is a cop out, particularly for a statement product with a price tag to match. Any improvement in wow and flutter must improve the enjoyment of music per se - musical timing is fundamental. They should shed some of the bling and provide a better drive system. Unfortunately I suspect market demand for bling over substance is a driver these days. Go at stand at an audio show and see how many folk make value statements on performance based solely on looks. |
Halcro You have edited out the most significant comment by Gunther Frohnhoefer of Acoustic Signature with regard to wow and flutter But, yes, the direct-drive motor will still produce better wow/flutter values because we use belts, and belts are worse in wow and flutter than a direct-coupled motor.It appears that they use stretchy belts. I suspect they have focussed on lowest noise and the stretch belts are a bandaid. As an aside he claims the 6 AC motors get the 32kg platter on the Invictus up to speed in under 10 seconds. My Final Audio VTT1 which uses one large AC motor can get its 26kg platter up to speed in less than 1 revolution ( 1.8seconds ). So I can only conclude that the Invictus uses weaselly motors and stretchy belts. I also owned a Platine Verdier - weaselly motor and stretchy belt - the replacement of the Verdier drive system with that from the Final demonstrated clearly that low power motors are a source of instability even when using high inertia high mass platters. For best speed stability in belt drives you must have high inertia, high torque stable drive system and non stretchy belt such as silk or kevlar. I also note that he comments that compared with Direct Drive motors he can get high quality AC motors at lower cost. He seems oblivious to the possibility of using AC motors in DD's or Induction motors for that matter. Overall I am not impressed and sceptical about a TT, the Invictus, that has no published specifications on performance nor any technological information available. Furthermore their Tiderfolon bearing is simply an self lubricating material - it is not possible for it to be frictionless as claimed on their website. I use a custom self lubricating polymer bearing in my 1960 Pioneer broadcast idler drive TT ( that blew away the Platine Verdier in speed stability ), its not that radical. |
lewm Lewm, You are wrong when you say there is no such thing as centrifugal force. Centripetal force is that at a right angle directed toward the centre of the axis of rotation. Centrifugal force is the apparent force, equal and opposite to the centripetal force, drawing a rotating body away from the center of rotation, caused by the inertia of the body. Centrifugal and centripetal are opposite sides of the same coin. If you look at the platter from the outside you see centripetal force, if you sit on the platter you feel centrifugal force - get it. Newton’s First Law states that “A body at rest will remain at rest, and a body in motion will remain in motion unless it is acted upon by an external force.” If a massive body is moving through space in a straight line, its inertia will cause it to continue in a straight line unless an outside force causes it to speed up, slow down or change direction. In order for it to follow a circular path without changing speed, a continuous centripetal force must be continuously applied at a right angle to its path. |
fleib Fleib, You don’t seem to understand how a direct drive TT works. Half the motor is coupled to the platter, the other half of the motor is connected to the plinth. If you hold the TT upside down by the platter, then the plinth will spin. The mass of the relative mass of the plinth to the platter is relevant and the rigidity of the coupling of the half of the motor connected to ground affects speed and articulation. Clearly Raul is unable to here the effects of a rigid plinth and motor coupling in his system. |
Fleib, Centripetal comes from the latin words "centrum" - centre and "petere" which means to seek. I can assure you that when using centrifuges the contents do indeed fly away from the centre, not towards. If you have any doubt, at the next carnival you can attend, take a ride on a horizontal spinning wheel and leave your seatbelt off. Then you can report back to us whether you flew back towards the centre or indeed away from the centre. |