Hello Halcro,
Based on your experience, which JVC motor has morer torque,
The TT-71/81 or the coreless TT-101?
Thanks!
Doron |
|
Ok, found it!!! (The spindle height adjustment screw).
Removed the bottom black cage and it it's a brass large flat screw at the bottom.
Once I screwed it in slightly, the shaft went forward and the clearance/axial float of the spindle/shaft was reduced a bit. It still exists but just smaller. Is this normal?
The platter now rotates freely now (no scraping) and the motor locks on both speeds readily.
Thank you so much!!!
Doron |
Hello Harold,
The Oracle Delphi Mk II:
I agree with you that the new revisions of the Oracle do not bring something special to the table (pun intended:-)). The heavier platter with the o-rings on the circumference and the nylon screws to support the journal bearing does not really do anything. I especially dislike the acrylic mat which sounds hard and lean to my ears and think that the groove isolator is a much better choice.
The Oracle suspension is probably the best on the planet. You can hit with your fist on the acrylic base while it is playing and the needle would not skip.
Unlike designs like the Avid, Linn or Thorens, the springs are suspended rather than compressed, which helps getting a piston like action rather than wobble like most sprung designs. Sound wise, it is a king of micro dynamics, like the Quad ESL of the turntable world.
It retrieves air between instruments, textures and spatial information like no other.
The two main weaknesses of the design, in my opinion, are:
1. Speed stability - the oracle motor and belt were somewhat iffy in my mind. Even the turbo power supply and newer motors do not really overcome the weakness in maintaining speed stability and avoiding cartridge drag in transient.
2. The suspension is very effective at filtering noise which translates to pitch black backgrounds but it is also a source for energy drain which robs macro dynamics. Mass loaded TT always sound more impact-full and muscular compared to the Oracle, given the same arm and cartridge. |
Thanks, Halcro!
Its cooking all right. Seems to work fine once the bearing/spindle was lifted a touch. Dead quiet and knock on wood, everything seems to function correctly.
Next is to re-drill the motor cavity in my console/plinth to allow for the deeper cavity that the TT-101 requires (we originally drilled it for the shallower TT-71).
I will share my experience of the differences in sound of these two motors.
Cheers and thanks again for the invaluable help,
Doron |
Thanks for the wonderful advice, guys!!!
I cannot thank you enough.
You just saved me a huge heartache of having to ship this unit back to UPS and get a full refund when I had much better plans for this baby...
I was a happy Oracle Delphi Mk II owner until two weeks ago. Had it installed and its suspension correctly tuned (a royal pain) with numerous arms and cartridges in the last 5 years:
Carts: DV 17D3, Benz Wood SM, SAE 1000 E and LT, Adcom Cross-Coil (another Coral based cartridge), Shinon Red Boron and even EMT JSD-5 Gold and the currently installed EMT HSD-6. My previous arm was Alphason Xenon MCS and now I am working with a Zeta which I absolutely love.
Long story short, always wanted to try a properly CLD plinth with a JVC DD motor so I got a JVC TT-71 motor and with the great woodworking skills of a dear friend built a 50 lbs, 9" tall, birch plywood plinth with solid ebony arm board for the TT-71/Zeta/EMT HSD-6. Basically I have two Zeta arms so I moved the one from the Oracle (with its added counter weights so the weight is closer to the gimballed bearing - great tweak btw) to the JVC plinth. I can call this now: "removable tonearm" as a twist on "removable head-shell":-). This JVC T-71 in its new plinth, walked all over my trusty Oracle. It was bold, muscular, dynamic, full sounding and much smoother, all at the same time. Macro dynamics were explosive compared to the Oracle. The only area where the Oracle did slightly better was separation of instruments and micro-dynamics like textures retrieval (like the asperities of a cello’s bow grinding on the strings, etc).
Adding some weights on top of the JVC plinth improved the micro-dynamics retrieval so we have concluded that with mass loading its go big or go home and with the idea of a friend, decided to build a crazy plinth: 36" tall, solid baltic birch plywood, cladded with a thinner sheets of plywood for added weight and for better aesthetics. It sits on my basement's concrete floor with the help of 3 massive, 5/8" (!) steel spikes that look like M61/Vulcan rotary cannon ammunition:-)
This baby was now weighing ~280 lbs and is basically a console, very similar in concept to the Denon DP-308F recording/mastering professional TT.
Even without the TT-101 in there yet, it is the best sounding TT I have ever heard, regardless of price and I heard many, 5 figure TT's like Well Tempered, various VPI’s, Avid Volvere, Scheu, Revolver, Oracle Mk V, fully loaded Linn LP12, Jean Nantais Lenco reference and even the Kuzma Stabi XL4 with air-liner air bearing tangential tonearm and Dynavecor XV-1 cart, which is the closest to it in sound, judging from my memory (only the Kuzma is a $40K TT before the arm and cartridge...)
It has been a dream come true for me and I can only imagine what the TT-101 will bring to the table (pun intended).
Thanks again for the invaluable pieces of advice!
Re the capacitors: removing the cage from the TT-101 reveals two stories of electronic components…many capacitors. Which ones do you replace? All of them? Do they need to be the same or any similar specs of capacitance and voltage will do?
Thanks again!
Doron |
OTL driving panels is surely a very good match. I have heard McAlister Audio OTL 195 driving Acoustat 3 with great ease (not an easy feat with speakers that swing impedance from 0.5 to 40 ohm!). King sound, like wise.
The Beveridge are very insteresting design.
I am not a panel guy but do appreciate their incredible transparency, their mid-top end coherence and their big sound stage.
I still like my "box colorations" and my trusty mid-bass:-) a matter of personal taste.
The Joule OTL is fairly full bodied OTL due to some 5751 driver tubes. With the Joule LA-100 Mk III premap its a very sexy/sensual sound (not muffled but very liquid) and a match made in audio heaven for my taste. Not sure the Joule is panel material though. Maybe the more powerful monoblocks can handle the low impedance but these take a lot of real estate and you could sell your furnace...
Someone wrote a beautiful piece about the Joule OTL's. I agree wholeheartedly:
"audio shows take the romantic sheen of cute packaging and sales literature very quickly. Once fatigue and impatience set in, you discover how much mediocrity is being promoted, and how few designs rise above the fray. The Joule amps exceeded my expectations. The second I heard them, I immediately knew what was missing from nearly every other amplifier on the market. This was the only amplifier I heard that could keep all the harmonic information together in one coherent image. It sounded like other designs were suffocating the harmonics, but hiding the damage behind oversharp highs or thumpy bass. The Joule is technically underdamped, but the bass has the rare quality of being tuneful, rather than punchy or visceral. This ability to be true to tone is the great distinguishing qualty of Joule. The complexity of piano strings is fully revealed instead of glary banging. Large stringed instruments have "cavity" , as if you can hear whats happening internally in the instrument. If classical music or acoustic music of any stripe is you favoured listening, Joule will absolutely ruin you for any other amp. It is the most civilized tube design in the world, if not the coolest running or easiest to live with. This isn't a toy, and it isn't ultra-convenient. You won't want this for ear-crushing boozy gatherings or adolescent angst sessions. It is an adult experience in the best sense of the word" |
Agree. Not all panels are created equal. I agree with you on the Magnepan.
I heard Martin Logan, King-Sound, Quad ESL and various models of Acoustat including 2+2, 3, 33, 4, 66.
The best of best of the lot was 3 located between two rooms (so it had almost the same distance to the back wall as to the front wall) with very high ceiling in the listening room. Dipole powered sub (two woofers back to back) included.
Driven by push pull tube amps and by OTL's.
Sound stage is huge, clarity is unparalleled, background is pitch black and it's quite dynamic too, unlike Quad ESL 57.
Probably the best implementation of ESL I hand ever heard.
Again, depending on source material, to my ears, mid bass was missing and bass to midrange connection was not to my liking.
Its a very impressive big orchestral pieces material. Just not one that I can personally live with. I am missing the wood:-)
Its interesting that in speaker choices there are camps:
Horn guys can never settle for anything else, ESL ditto (they are very sensitive to "box colorations" and to what they describe as separate drivers rather than one coherent sound wave, at least in the mid to upper frequency) and box speakers guys are also pretty stubborn in their choice.
In the end speaker choices are like "choosing" your wife:
She is not perfect but she is perfect for you, if you know what I mean:-)
I never changed my main "lowly" Sonus Faber Grand Piano Home speakers after hearing countless other speakers, including, comparing them, in the same room to "higher end" Sonus Faber speakers. Just to show there is a reason why I chose them in the first place,
The main thing is to chose a pair of speakers that work in your room (can't over emphasize that because speakers are never one size fits all) and to work with them rather than becoming a "speaker womanizer" who swaps speakers left right and centre to never assume each spraker's potential rather than picking a pair and find out how to make them sing.
Just my opinion based on my experience. |
I have noticed that some of the members here had experience witn Lenco and other idler wheels as well and was wondering what was your impression of the results compared to a DD in a heavy plinth.
My experience is limited to a friend's JN Reference with Analogue Instruments, 12" Cocobolo, Uni-pivot tonearm and various cartridges (SAE 1000 LT, Koetsu Black, low output Elac).
On the plus side:This combo had very good flow and sounded very smooth.
On the negative side: noise floor was high, which made dynamic contrasts lacking. Air, 3D and detail were missing.
A while ago, 3 audiophiles from Canada conducted a "Lenco Challenge": building a CNC machined, heavy birch plywood plinth for a donated Lenco drive, greasing the bearing and following The Lenco Heaven instructions.
Results were not super positive when compared to modern tt's like DD Brinkmann Bardo for instance:
http://www.canuckaudiomart.com/forum/viewtopic.php?f=32&t=28246&hilit=lenco+project+brinkmann&start=285
I was wondering what was your experience? |
Hi and thanks for the thorough response!
What I meant by noise is not audible noise as much as high noise floor or lack of pitch black background which hurts the 3D and the dynamic contrast and gives you a sense of flatness to the sound.
It is still amazing that with 4 pole (!) motor, 50-60 dB S/N and wow and flutter at 0.6% one gets results that are not far off DD's with 75 dB S/N, core-less motor and 0.02% wow and flutter.
A lot of isolation, superior bearing and better platter, somewhat reminiscent of the EMT 927 and 930 idlers, I assume.
The one thing that these idlers have in spades is torque (which translates to drive, a sense of flow and PRAT) but my question is:
How much torque do you really need?
If you manage to overcome cartridge drag on transients with ease do you need the extra torque?
Does a Technics with 16kg cm sound more convincing than a TT-101 with 1.3 kg cm?
Lewm, I agree with you that opinions are just that, opinions.
At the end each of us have different reference points and preferences and what appeals to one person might not appeal to other.
I remember having a discussion with a guy who was very opinionated about things audio. He talked about turntables, about building his own record cleaning machine, about soundstage and audio preferences.
When he visited me and heard my system he said that the midrange intimacy and concentrated sound was too much to bear.
When I visited him I saw two Kef mini-monitors the size of Bose AM-5 located on the sides of a plasma TV with 1,600 watts SVS sub.
Basically a Bose sound - bloated bass and two tweeters with no midrange to be found. This is just to show you how amazingly subjective this hobby is. Who am I to judge? To each his own.
Many audiophiles will look at my gear and will say to themselves that its mediocre and that's fine with me. In the end its about pleasing our heart and not about convincing others that our sound is great.
I believe that with this understanding, when it comes to opinions, one can judge a differential (one item compared to another when all other parameters are the same).
Based on what I read between the lines, it seems that to make an idler wheel work one needs a heroic effort: see EMT 927 with its industrial washing machine sized motor and steam train flywheel sized platter and EMT themselves moved to DD once they could (once torque was sufficient to start a song in less than half a second when broadcasting). |
Hello,
Agree with comparing apples to apples, viscosity wise, when comparing the two oils.
Here is some data re viscosity of multiple grades oils:
http://www.viscopedia.com/viscosity-tables/substances/engine-oil/
The multiple grade is not crucial in our case because we are dealing with relatively low temperatures (in the 70-80F) but can relate to the viscosity in the chart.
Adding weights and comparing stop times should give some indication but the best proof is in the listening. Less friction will translate to quieter background and lower sound floor.
Hope this helps,
Doron |
Minh,
You could use the 5W20 in both oils.
Good enough for this application, in my mind.
Just make sure to clean and dry the bottom plug/oil pan and the spindle/bearing from the RP well as it tends to adhere to metal parts and maintain its lubricity.
Re the formulation of synthetic oils:
For most oil companies, oil is a by product of refining crude to fuels.
It's a thorn in their side. They buy an additive package from companies like Lubrizol who specializes in this field. The additive package will contain, anti rust and oxidation agents, anti foaming, metal deactivators, viscosity modifiers, etc, etc.
Then, oil companies will package it nicely, put a photo of a tiger or a race car or whatever and sell it with all sorts of marketing claims...
Synthetics are a bit different in the sense that the base stock is manufactured by cracking ethylene to a long chain of hydrocarbons which do not contain impurities like in the case of standard mineral oil.
The main advantage of synthetic base stock is prolonged life and flatter viscosity curve (less change in viscosity as the temperature changes, which is desirable).
Both kinds will be blended with the additive package.
Royal Purple started as an industrial oil blending facility with two main advantages:
1. They filter and clean their base synthetic stock to a high level (ISO cleanliness of 14/13/11) - most important in process compressors and rotating equipment in general.
2. They blend their own additive package and in it, they include their secret recipe to a potent anti wear agent which increases film strength and reduces friction to a very high degree.
Of course the world is full of marketing claims, snake oil and $20,000 speaker cables which makes any claim a suspect,
I just have very good experience with RP in the industrial realm, which instigated my curiosity re my audio hobby, specifically my turntable bearing (both my previous Oracle Delphi and now my TT-101).
Btw, I am not an RP representative.
I am a chemical engineer who deals with mechanical seals and rotating equipment in general. |
Mat wise, did anyone try the old Oracle groove isolator?
It's a bit smaller than the TT platter but thick enough to be higher than the edge. I have tried carbon fibre (Boston) and Acrylic hard mat and found them hard and bright sounding. The Groove Isolator seems to have a very good tonal balance to my ears without losing details/muffling the sound.
Your mileage may vary. |
Sorry Lew,
My bad, Carbon Graphite it is. In any case, didn't work for me.
Re material's expert, I'm far from being an expert on anything.
I always say: I learn everyday, I'm going to die stupid in the end, but I'll die trying...:-)
Mat sound, like cables (and maybe this whole hobby) is subjective.
A dark sounding system (define dark) can benefit from a hard mat and a bright system would benefit from a duller sounding mat.
Without references points any impression is subjective.
its just trial and error for any one of us.
Generally, I see audio as a combination of engineering, physics and cooking, all in one hobby...unlike engineering and physics, cooking and taste is a highly subjective matter. Otherwise we would all have the same system.
Not even getting into the fact that we all have very different rooms (and rooms account for very high percentage of the sound).
My personal experience in the context of my system/taste is that softer mats like cork, pig skin, delrin have better sonic results. |
Hi Halcro,
I have a few more questions if you don't mind.
Acquired a TT-101 motor on ebay.
Arrived today and I unpacked it and was shocked:
At first glance it appeared DOA.
Without the platter installed, as you press 33 or 45, the spindle is making grinding noises and never gets to the proper speed (33.33 or 45). The LED display shows the motor is rising in speed to random numbers below the required speed and then the counter goes back to zero and re-starts again.
Putting the internal counter switch on "hold" gets this re-counting to stop but again, speed never gets to either 33.33 or 45.
When assembling the platter on the spindle, the bottom of the platter scrapes against the base underneath it and when pressing the 33 or 45 does not turn at all. On a closer look you can see that the platter is eithef not concentric with the base's outside diameter, is not sitting in the centre as if the spindle is bent or out of centre or sitting too low.
On an even a closer look yet, finally picked on what's wrong:
The spindle is a cone which enter an opposing cone in the platter's hole.
It seems that either the spindle cone "shrank" from its original size and/or the opposing concical hole in the platter "expanded" or the spindle sits too low to engage and support the platter above the base.
The size tolerance could have been a temperature issue (expansion and contraction).
End result is that the platter sits too low and scrapes against the base,
So? I took a skinny tape and put on the spindle cone (like a very thin shim) and guess what? The platter locks on the right speed, it rotates quietly and stops on a dime when I press the stop button,
So few questions:
1. The spindle seems to have axial freedom/clearance. In other words without the platter, when I gently pull the spindle it comes up a few thous. I have noticed this on my TT-71 motor too. I assume it is relying on gravity and the motor bearing is not a thrust bearing but not sure.
From your experience, is this slight axial freedom normal?
2. When trying to rotate the spindle without the platter it seems noisy and doesn't lock on 33.33 (it does on 45 but takes a while).
As soon as I put the platter on, its dead quiet and locks beautifully on both 33.33 and 45. Is this normal? Does your TT-101 functions similarly?
3. What's with the spindle cone/platter matching cone clearance?
Have you ever experienced such an issue?
Could it be a shipping damage (bumped on the floor and the spindle moved down from its original place, which would have resulted in the same exact result?
Any additional thoughts/advice would be most welcome!
Thanks and kind regards,
Doron |
Hello and thank you all!!!
Much appreciate your help!
1. Re the platter/spindle height adjustment screw, do you need to remove the black upper motor cover to access this screw?
2. Any chance you could send a photo showing it? (doronor3 at gmail)
3. In addition without the platter installed, is there an allowable, slight (~1/16") axial movement of the spindle/shaft?
In other words, if I pull the spindle upwards by hand, it rises about 1/16" from its normal rest position.
Is this normal or is it an indication of excessive axial float?
Thank you kindly!
Doron |
Hello,
Finally got my TT-101 installed in my solid 40" tall birch plywood plinth with Zeta tonearm and EMT HSD-6 cartridge.
Then stayed until 2:00AM listening with fascination!
This is the best sound I have had in my system by a large margin.
So how does the TT-101 compare to the previously installed TT-71?
Smooth as butter, more refined, darker background, like voices come from outer space, so all the oracle's advantages (micro dynamics, air, pitch black background) + the macro dynamics, impact and the tonality of the TT-71, simply incredible!
Very happy and thankful to you all for your invaluable help in fixing the minor issue.
Off topic: Lewm, noticed OTL amps in your system. Great choice!
I own Joule-Electra LA-100 Mk III and VZN-80 OTL.
Heard other OTL's too (Tenor, McAlister).
OTL's are the most effortless, natural sounding amps out there, in my opinion. Closest thing to a wire with a gain...
Cheers,
Doron |
Hello Lewm,
I am well aware of the potential. Acoustat had model X which had the OTL directly driving full range panels.
My "issues" with panels are not how hard they are to drive.
I am well aware of their strengths. My issues is maybe my own personal perception but panels always make me analyze the music instead of listening to it and immersing myself in it. They give me an illusion that the voices come from outer space but the cavity of instruments are missing somehow as if the cavity was blocked or instruments were much flatter than what they really are. To me they sound like they miss the resonances of a stringed instrument but panel guys will say I miss box colorations, which is maybe the case.
Hard to explain why panels sound like that to me, but perhaps it has to do with mid-bass cancelation due to the dipole construction (destructive interference in physics). In addition, I always panels as coherent from the midrange and up but not so from lower mid-range to the deep bass.
I believe that some people are more sensitive to upper frequencies and some are more sensitive to lower frequencies and then you have the horns, which I could never warm up to due to my own preferences in sound reproduction.
In the end, at the highest echelons of audio, when clarity is achieved, our hearing and perception defers and everyone has his own preferences.
Otherwise we were all owning the same exact system, which would have made this hobby pretty boring…:-) |
Lew, re:
"I am surprised that one good oil would be noticeably superior to another good oil in a tt turning at most 45rpm", studying fluid mechanics would indicate that the toughest lubrication applications are slow speed as opposed to high speed where lubrication "wedge" can be easily generated by the fast moving parts.
That is why slow turning gears use high viscosity lubricants with extreme pressure additives to reduce wear and minute "welding" of the gear parts.
This is basic lubrication.
Viscosity is part of the equation. Another part is film strength and anti friction agents to support moving parts at high pressure.
The lubrication of a tiny ball bearing moving against a disc at slow speed is actually a tough application. It's like stilettos: The pressure of the bearing is fairly high (P=F/A) where A (area) is very small and F (force) is not insignificant and the slow 33 or 45 RPM is not sufficient to easily build a fluid film between the ball bearing tip and the disc.
A good lubricant can help since reducing friction in this point will benefit in less noise which transfers from the spindle to the platter.
Just my thoughts and personal experience.
Stop times are dictated by viscous shear (internal friction of the fluid layers) and asperity contact at the tip of the bearing. The higher the lubricant's film strength the less the asperity contact would be a factor and stop times will be dictated by viscous shear. That is why adding weight didn't really change our results with RP. |
